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September 30, 2005

New tropical depression in the Atlantic

The seasons' 19th tropical depression formed today in the eastern Atlantic Ocean, and it could become a tropical storm over the weekend, the National Hurricane said. If so, its name would be Stan.

The bad weather was located 665 miles west southwest of the Cape Verde Islands, but its predicted track suggests it will not become a threat to land. Here is the advisory. Here is the view from space. (The satellite image will go dark as night falls over that part of the Atlantic.)

Posted by Frank Roylance at 5:30 PM | | Comments (0)
Categories: Hurricanes

Flooded manhole swallows rickshaw driver

Here's a new twist on "Turn Around. Don't Drown" - the National Weather Service's admonition against driving through flooded roadways. It's an item from a newspaper in Dhaka, capital of Bangladesh, where torrential monsoon rains today dumped up to 90 mm of rain (that's 3.5 inches). Click here.

Posted by Frank Roylance at 2:41 PM | | Comments (0)
Categories: Events

October: Can snow be far behind?

It's been 26 years since Baltimore has seen snow in October. Maybe global warming has erased the possibility. But the fact that it CAN snow in Baltimore in October is enough to rate a mention as we welcome the new month, which starts tomorrow.

A total of nine snow events have been recorded in October, record-keeping in Baltimore began in 1871. The earliest ever recorded occurred on Oct. 9, 1895. It was just a trace, nothing measureable. And that record was matched with another trace on the same date eight years later - in 1903. 

The earliest measureable snowfall was 0.3 inch, on Oct. 10, 1979. It's been much longer since we've seen any appreciable accumulation in October. The weather service records show a 1.3-inch snowfall on Oct. 19, 1940. And 2.5 inches fell on Oct. 30, 1925. That's the record for October.

I've always felt October was the prettiest month in Maryland, perhaps in a tie with April. The temperatures are comfortable, the sun is warm, the leaves are turning and we generally shed all the humidity that can make summertime unpleasant.

Average daytime highs in October - using the 30-year average at BWI - range from 73 degrees as the month opens, to 62 degrees by Halloween. The average overnight lows slide from 50 down to 39 degrees.

But it can also be pretty warm, and very cold. The record highs range from 97 degrees (on Oct. 5, 1941) to 80 degrees (Oct. 25, 1902).  The record lows start at 36 degrees (Oct. 1, 1947), and slip on down to 25 degrees (on Oct. 24, 1969 and Oct. 31, 1966).

The average October produces 3.16 inches of rain. It will be interesting to see how long this current mini-drought continues into the autumn. BWI has seen just 0.67 inch of rain since Aug. 28.  The wettest October day was Oct. 10, 1929, when 4.38 inches were measured in the city.

The driest October was in 1963, when only a trace was recorded at BWI. The wettest was in 1976, when 8.09 inches were measured. We'll sum up September tomorrow.

For stargazers, October promises an increasingly impressive view of the planet Mars. We're moving toward the Earth's closest approach to the Red Planet since 2003 (on Nov. 3), and the nearest we'll see it again until 2018. It's already a brilliant spectacle in the eastern sky in the late evening. It's the biggest, brightest, reddest star-like object up there. You can't miss it.

Venus will remain a bright presence in the western sky after sunset all month. Look for the crescent moon to join her on the 4th or 5th.

Posted by Frank Roylance at 11:21 AM | | Comments (0)
Categories: Almanac

September 29, 2005

Arctic summer ice is shrinking

Scientists say the ice cap on the Arctic Ocean is shrinking. Each summer it melts back some. But long-term observations show that the maximum extent of the summer ice - its total area - is getting smaller over time, and this summer reached a new record. Here is a graphic representation of what's been happening in recent years.

The experts blame human-induced global warming for at least some portion of this phenomenon. And there is concern about its impact on habitat for polar bears, seals and many smaller creatures that depend on the ice and cold waters. The phenomenon appears to feed on itself. Ice reflects solar energy back into space. The more dark, open water becomes exposed to the summer sun, the more the Arctic Ocean heats up, slowing the formation of more ice in winter, speeding its spring melt, and opening still more ocean to the sun.

This could all have a profound impact on climate and weather, not to mention commerce if shippers one day find an ice-free summertime shortcut, through the arctic, between the North Atlantic and the North Pacific. Explorers looked for one for centuries. They may finally get it.

The Sun carries a New York Times wire story on the latest discoveries on page A3 today.

Posted by Frank Roylance at 10:35 AM | | Comments (0)
Categories: Climate change

Gusty cold front blowing through

1:20 p.m. Update: The front has passed, producing gusts to 31 mph at BWI, but barely a drop of rain. Just 0.01 inch was recorded at BWI. Skies should clear up nicely now for the weekend. The strip charts show clearly how the front passed between 10 and 11 a.m. The wind speaked, the temperatures began to fall, and the barometer began climbing again. Click here for a look, and scroll toward the bottom.

The National Weather Service earlier issued a wind warning for gusts to 50 mph as this cold front moves through the area. There was a clap of thunder in downtown Baltimore about 10:15 this morning. Here's the current radar image.

The good news is that this front should move through quickly, with rapid clearing and nice, clear, cool weather right behind. The bad news is we won't get much rain out of it. I've had just one tenth of an inch all month in Cockeysville. The airport reported just .66 inch in September as today's front approached. We'll see shortly how much more we get this month, and how September 2005 will rank among the driest on record here.

Update: With just 0.01 inch more in the rain barrel, BWI ends the month with 0.67 inch of rain, making it the 10th driest September on record.

The dry weather could dull the display of fall colors along the Blue Ridge, according to the Richmond papers.

Meanwhile, the air behind the front is sending temperatures below freezing in the upper Midwest. Here's the newspaper report from Minnesota

(Which makes me wonder.... Where will "online news" come from if declining newspaper circulation forces cuts in the newsroom staffs of newspapers around the country? The fact of the matter is, most of the news we read "online" is originally reported and written by newspapers. Wire services get most of their content from member newspapers. Broadcast outlets rely heavily on local and national papers.

(No other news organizations have the trained manpower - sheer numbers of reporters and editors - to get the job done. If newspapers decline, everyone's access to information, and our vital checks on government power, will decline along with them. We can't turn back the clock. People are going to get more of their news from the Web, and less on paper. If you're reading this, you're a case in point.

(So newspapers need to find a way to capture a significant income stream from their online products, and readers (or advertisers) will need to be willing to pay something for the service. I notice the New York Times has begun to charge for online access to some columnists. There's no free lunch. But I digress. Your thoughts are always welcome.)

Posted by Frank Roylance at 10:18 AM | | Comments (0)
Categories: Forecasts

September 28, 2005

Almanack's snow forecast

The new (2006) Hagers-town Town and Country Almanack just arrived in my mailbox, with its forecast for the winter to come. The news isn't too bad if you don't like snow. The "conjecturer's column" predicts more "cold days" (with highs below 46 degrees) than last winter but fewer "wet days" and fewer "cyclonic storms." On the whole, about average.

November and December will see just "average" temperatures and precipitation. January looks like it could be the snowiest month, with below-average temps and above-average precipitation. February will be colder than average, too, but with only average precip. And March will bring both above-average temps and below-average precip.

The old Conjecturer - Bill O'Toole, a Mount St. Mary's math and computer science prof. - says the season's first snowstorm, at least for Hagerstown, will begin Dec. 19, with more chances for snow on Christmas Eve and New Year's Eve.

To their credit, the folks at the Almanack are straight about their track record, noting that last winter's forecast was about half right. Or half wrong. "This was not one of our best years," O'Toole confessed. He forecast 111 cold days and got 80, of which 66 fell on the predicted dates. He expected 62 wet days and got 56, including 32 on the right dates. And of the 21 cyclonic storms that showed up, 14 arrived on the right dates.

But when he's right, he's right. In the 2004 edition, O'Toole forecast a "tropical storm" between Sept. 16 and 19 and posted a tornado watch for those dates. On the 17th, the remnants of Hurricane Ivan passed through town after triggering a large outbreak of tornadoes in the region.

Then again, my old railroad pocket watch hasn't run in years. And it's still right twice a day.

Posted by Frank Roylance at 6:48 PM | | Comments (1)
Categories: Forecasts

Tropical weather

The tropical disturbance in the Caribbean has fallen apart, for now. But the National Hurricane Center continues to watch what could still, as conditions improve, develop into the next tropical depression. The good news is it's the only bad weather in the wings for the Atlantic basin. We can use the break. Here is the advisory. And here is the view from space. (It's the smudge of clouds east of Jamaica and south of eastern Cuba. Not too impressive.

Posted by Frank Roylance at 10:46 AM | | Comments (0)
Categories: Hurricanes

Cold front, rain, then autumn

If you need some outdoor time, for raking leaves or cleaning up the garden, or just a mental-health walk in the park, take it today. The forecast calls for a cold front to pass through tonight and tomorrow, bringing a 60 percent chance of rain and gusty winds on Thursday.

But it will pass quickly, and the rest of the week, while cooler and more autumnal than we've seen so far, will be sunny and beautiful. The nights will be clear, too, this weekend, So if you missed Venus and Mars last night (see previous post) the show continues each night, with only slight changes in the curtain times.

Posted by Frank Roylance at 10:37 AM | | Comments (0)
Categories: Forecasts

September 27, 2005

A great night for planet-gazing

The skies have cleared beautifully, making this a perfect night for planet-spotting. Step outside this evening after sunset, turn toward the west and take a gander at Venus. No need to book it out of town. It's the brightest object in the western sky, and it won't set until about 8:30 p.m.

Then, take a break, but get yourself and the older kids back outdoors by 9:30 or 10 p.m. Turn toward the east this time, and take in Mars. The Red Planet will be the brightest thing in the eastern sky - brighter even than Sirius, the brightest true star in the winter sky. I've already had one call in the past week from a reader wondering what that big red beacon was. Mars is cruising toward its closest approach since August 2003, and by the end of October it will shine bigger and brighter than we'll see again until 2018.

For more on Mars and this fall's brilliant show, click here. And for a nifty audio-visual primer on the fourth planet from the sun, click here.

Posted by Frank Roylance at 6:26 PM | | Comments (0)
Categories: Sky Watching

New storm brewing in the Caribbean

The National Hurricane Center is watching the development of a new tropical system in the Caribbean. It could become the next tropical depression in the next day or so, and could eventually become a new tropical storm threat to the Gulf of Mexico. Here is the tropical outlook. And here is the view from space.

Posted by Frank Roylance at 11:01 AM | | Comments (0)
Categories: Hurricanes

Just a wetter

Asked if she wants another beer before she goes, my mother-in-law rarely declines. But "Boom Boom," as the kids call her, is never greedy. "Just a wetter," she says. Only enough to wet her whistle.  Well, that's about all we got yesterday as a cold front passed through. The rainy change in weather systems banished the humid, tropical air that came through with the remnants of Hurricane Rita, and delivered this beautiful, dry air from the northwest.

I recorded just 0.08 inch on the back deck in Cockeysville. That brings the month's total for my sorry old tomato plant to a whopping tenth of an inch of rain.

At BWI, Rita's farewell "wetter" dropped just 0.11 inch of moisture. That brings the official month's total to 0.66 - just two-thirds of an inch in all of September, with three days to go and little prospect for more. Central Maryland is now experiencing what the US Geological Survey classifies as a "moderate drought" that stretches from the New York City area southward to central North Carolina." Here's the drought map for Sept. 20.

The forecast offers just a 40-percent chance of rain late Wednesday into Thursday. The numbers could change, but for now, this month still stacks up as the 10th-driest September on record in Baltimore.

Looks like we'll be running the sprinklers again this weekend. On the other hand, it's great weather for painting.

Posted by Frank Roylance at 10:42 AM | | Comments (0)
Categories: By the numbers

September 26, 2005

Satellite view of Rita flooding

The flooded coastline of Louisiana darkens from green to dark blue in these before-and-after photographs from a NASA Earth-observing satellite.

Posted by Frank Roylance at 6:24 PM | | Comments (0)
Categories: Cool pictures


Umbrellas sprouted today in downtown Baltimore as a light rain scattered sprinkles across the region. It is the first rain we've seen, officially, since Sept. 15. And it's only the third day of rain this month.

None of it has yet registered, as of this writing, on the National Weather Service web page. But it's looking plenty wet out the window. Puddles, raindrops, the works. More serious rainfall may be in the wings, as the National Weather Service warns in this hazardous weather advisory, issued earlier today. An approaching cold front could spark some gusty winds and thunderstorms overnight.

Motorists would be wise to slow down. After 11 rainless days, the roads are no doubt slick with a thin sheen of oil. Driving will be hazardous until the rain and traffic can scrub it away.

Posted by Frank Roylance at 5:57 PM | | Comments (0)
Categories: Events

Happy Anniversary to us!

The Baltimore Sun's WeatherBlog is celebrating its first anniversary this week. Since going live on Sept. 24 last year, the Blog has published 540 posts and 144 comments from our readers.

In all, we have logged about 150,000 blog visits, and 250,000 page views.

Snow, or the threat of snow seems to be our biggest activity generator. Our busiest week was the one beginning on Feb. 21, when we clocked 15,862 visits and 26,962 page views.

And for some reason people have better things to do on Christmas vacation week than to browse the Internet and visit the WeatherBlog. On the week of Dec. 27, we registered a record-low 717 site visits, and 1,290 page views.

We hope we're providing a useful service, and some interesting insights into the weather that affects our region, the nation and the world. We also attempt to alert readers to other interesting things that are happening in the sky, especially at night. We welcome any and all suggestions and queries. Just post a comment or drop us an email at 

And thanks again for visiting the Baltimore Sun's WeatherBlog, at

Posted by Frank Roylance at 11:58 AM | | Comments (0)
Categories: By the numbers

Rita rain relief

Rain from the remnants of Hurricane Rita could bring the Baltimore region some needed rain later today. And the chances of rain in the forecast increase to 80 percent tomorrow.

Most of the storm's moisture and energy has already been swept up into northern New England and Canada, as is clear in this infrared satellite imagery.  And that is not at all what hurricane forecasters were saying last Friday. The prediction then was that Rita would stall over Louisiana and drop rain across the East Texas/western Louisiana region for days. Instead, the storm drove inland, got caught up in the movement of continental weather systems and booked. So much the better for the Gulf Coast, which has had quite enough.

Posted by Frank Roylance at 11:12 AM | | Comments (0)
Categories: Forecasts

September 23, 2005

Gulf "loop current" stoked Rita

Scientists say hurricanes in the Gulf of Mexico are often stoked to Category 4 or 5 strength as they pass over the warm "loop current" that flows through the Gulf. Here's a satellite image showing the current's present location, and Rita's path across it. The data is based on altitude measurements by the joint U.S.-French Topex/Poseiden satellite and NASA's Jason satellite. Because water expands with higher temperature, warm water in the Gulf is actually 1 to 2 feet higher than cool water, allowing radar altitude measurements to provide a good measure of water temperature.

The image makes it clear why Rita blew up after passing through the Florida Straits, and why its top winds have slowed in the past two days as moved past the loop current's heat. Cool.

Posted by Frank Roylance at 4:02 PM | | Comments (0)
Categories: Cool pictures

Rita a Cat. 3, still dangerous

Hurricane Rita is bearing down on the Texas-Louisiana coast with top winds now slowed to 125 mph. That makes it a Category 3 on the Saffir-Simpson Scale of Hurricane Intensity. That's still a "major" hurricane, and still following forecasts issued days ago by the National Hurricane Center. Landfall is expected late tonight or early tomorrow morning.

Whatever damage the storm does at landfall will be aggravated by heavy rains. Rita is expected to stall after landfall, hanging around until Tuesday and dropping as much as two feet of rain. Major river flooding in the region is expected, especially in the area within about 100 miles of the Texas-Louisiana state line.

New Orleans is forecast to receive 3 to 5 inches of rain or more. That won't help matters there. The levees patched after Katrina have already broken, and water is pouring back into the city. On the other hand, most everything that's vulnerable to flooding is already ruined,  by Katrina.

Here's the latest advisory. Here's the predicted track. And here's the view from space.

Posted by Frank Roylance at 3:47 PM | | Comments (0)
Categories: Hurricanes

September 22, 2005

Houston, before the big blow

Here's a God's-eye view of the Houston/Galveston area on the day before Hurricane Rita moves in. Click on the images enlarge them.

Here's the weather forecast for Port Arthur, Tex. Be thankful it's not yours.

Posted by Frank Roylance at 6:00 PM | | Comments (0)
Categories: Cool pictures

Rita slows, but not enough

Hurricane Rita has continued to slow today, spinning down to 150 mph, according to the 2 p.m. EDT advisory. That's down from 175 last night. But it remains an extremely dangerous strong Category 4 storm that seems certain to do severe damage to life and property along the Texas coastline. The impact on the economy from a direct strike on the oil, gas and refining industry in that part of the Gulf can only be imagined.

Hurricane warnings are now flying from Port O'Connor northeast of Corpus Christi to Morgan City, La., due south of Baton Rouge. That puts the bullseye a bit east of Galveston and Houston, and the worst onshore winds and storm surge from there eastward through the heart of the petroleum industry's Gulf infrastructure. The hurricane-force winds extend 85 miles from the center, spanning a front 170 miles wide. Tropical storm winds reach out 100 miles farther. The stormwill arrive with a 15 to 20-foot surge, and 8 to 12 inches of rain. The region battered by Katrina could see 3 to 5 inches of rain - enough to outpace the pumps and reflood parts of New Orleans.

The good news, if there is any, may be that the farther the track moves east of Houston, the more likely it is the city will avoid the worst onshore wind and storm surge. The bad news is, a track farther east puts Louisiana, its fragile bayou country and New Orleans in deeper danger of a repeat disaster. We will all be reading and hearing about this storm for a long, long time.

Here is the latest advisory. Here is the latest forecast track. And here is the view from space.

Posted by Frank Roylance at 12:31 PM | | Comments (0)
Categories: Hurricanes

Fall arrives tonight

The Autumnal Equinox occurs this evening at 6:23 p.m., officially the end of Summer and the beginning of the Fall season in the Northern Hemisphere. For more, click here.

Posted by Frank Roylance at 10:08 AM | | Comments (0)
Categories: Almanac

A September for the record books

It could rain some more this month, especially if Rita's remnants head this way. But for now, with a bit more than a week remaining, September 2005 ranks as the 7th-driest on record in Baltimore. Only .55 inch has fallen, in two days. That makes it the driest September since 1970. Only 13 Septembers have seen less than an inch of rain since record-keeping began in 1871. It seems to average out to once a decade. Here's the list:

Year       Rainfall (in inches)

1884: .09

1967: .21

1906: .32

1930: .37

1970: .46

1941: .50

2005: .55*

1955: .56

1986: .58

1977: .62

1925: .75

1959, 1878 (tie): .82

* Through Sept. 21      

As the creeks have dried up, water levels in the city's reservoirs have gone down since June. It's the first time they've been significantly below capacity since June 2003. Here's how they stood on Wednesday:

Prettyboy: 86.78 percent

Liberty: 88.37 percent

Loch Raven:  89.19 percent

Combined: 88.2 percent

Posted by Frank Roylance at 10:06 AM | | Comments (0)
Categories: By the numbers

September 21, 2005

Rita is 5th-most-intense ever

The National Hurricane Center now says Hurricane Rita has become the 5th-most-intense storm ever measured in the Atlantic basin.  Katrina was the 4th. Here are the details.

Posted by Frank Roylance at 7:28 PM | | Comments (2)
Categories: Hurricanes

Texas takes cover as Rita approaches

Here are the warnings and advisories currently being issued by the National Weather Service for residents of the Houston area. Evacuations have begun in Galveston and Brazorias counties. The University of Texas Medical Branch hospital in Galveston has closed. People seem to be taking this storm very seriously. As they should.

Posted by Frank Roylance at 1:43 PM | | Comments (2)
Categories: Hurricanes

Coastal La. and Miss. also in peril

Although Rita appears headed for the Texas Gulf Coast, her winds and tides still threaten coastal Louisiana and Mississippi. Starting this afternoon, forecasters say, stiff hurricane-driven winds reaching 30 to 40 knots (23-34 mph) from the east will pile water onto low-lying stretches of southeastern Louisiana and coastal Mississippi. They're expecting storm tides 3 to 4 feet above normal. That could re-float debris all along the coast, and would easily threaten the hastily patched levee system around New Orleans, putting the city in danger of re-flooding just as the pumps seemed to be getting the job of drying the city done.

Officials are warning residents to be prepared to flee to higher ground. Here is the flood watch advisory issued this morning for New Orleans and the surrounding communities:






Posted by Frank Roylance at 11:21 AM | | Comments (0) | TrackBacks (1)
Categories: Hurricanes

Rita is a Cat. 5 - 165 mph

As forecast - maybe even more rapidly than anyone expected - Rita has exploded over warm Gulf waters. It reached Cat. 3 at 2 a.m., and after daybreak today was estimated to have grown into a Category 4 storm, with top sustained winds of 135 mph. When the sun went down yesterday it was a 100-mph, Cat. 2 storm as it squeezed through the Florida Straits.

UPDATE: Rita now has top sustained winds of 165 mph, making it a Catgeory 5 on the Saffir-Simpson Scale of Hurricane Intensity. For what that means, click here.

People living along the Texas coast have good reason to fear this storm, and every incentive to get out while the getting is good. Looks like a really bad time for them - somewhere on those shores - by Friday and Saturday.

The National Hurricane Center says the consensus of forecast models there point to a peak intensity of 125 knots within 24 hours. That's about 144 mph. But they say they would not be surprised to see Rita reach Category 5 strength - more than 155 mph. Katrina grew to a 175-mph Cat. 5, too. And like Katrina, which slowed to a 145-mph Cat. 4 storm at landfall, Rita is expected to weaken somewhat, too, either because of a process called eyewall cycling, or because water near the Texas coast is cooler than the deeper portions of the Gulf. But we're talking about a difference between awful and horrible. As NHC meteorologist Robbie Berg said yesterday, there are no best-case scenarios.

The best we can hope for is that Rita spins herself out over the Gulf or, failing that, goes ashore someplace where there are fewer people and less infrastructure. Avoiding Houston and Corpus Christi and Brownsville would be a welcome gift. AccuWeather sketches the coastal population.

Here is the latest advisory. Here is the latest forecast track. And here is how Rita looks from space.

Posted by Frank Roylance at 10:28 AM | | Comments (0)
Categories: Hurricanes

September 20, 2005

Rita now a Category 2 storm

Top sustained winds at Rita's center have reached 100 mph, making it a Category 2 on the Saffir-Simpson Hurricane Scale. Another 11 mph and it will reach Category 3 - a "major" storm - as forecast by the National Hurricane Center. Forecasters  expect Rita's top winds will reach 105 knots - 121 mph - over the Gulf in the coming 24 hours.

Thankfully, this storm seems to be moving much faster than Ophelia did. It's trucking along toward the west at close to 15 mph, limiting the time that wind, waves and rain can batter any given location. Ophelia poked up the coast last week at 4 mph, giving the Outer Banks a pounding for two days.

Here is the latest advisory. Here's the forecast track.

Posted by Frank Roylance at 3:16 PM | | Comments (0)
Categories: Hurricanes

Follow conditions in Key West

The weather instruments at Key West are still working, making it possible to track conditions there as Hurricane Rita passes through the Florida Straits. At last check, the winds were howling at 46 mph at Key West Airport - strong enough to make standing difficult. Gusts reached 56 mph, with some reports of gusts above 90 mph, although that did not show up immediately on the NWS data page. But, for what it's worth, the storm's eye appeared to be passing south of the island. The storm's highest sustained winds were clocked at 85 mph. With Rita already abreast of Key West, perhaps the worst will soon be over.

Here is the National Weather Service forecast page for Key West.

Here is the local radar image.

And here is a history of conditions there.

Posted by Frank Roylance at 1:14 PM | | Comments (0)
Categories: Hurricanes

Please, a drop of water?

Today may be our only chance for the rest of the week for some badly needed precipitation. The forecast offers only a 30 percent chance of rain today and tonight if a thunderstorm happens to develop, and happens to pass nearby. And even at that forecasters can see no more than a few tenths of an inch of rain in the offing.

So far this month the airport has clocked barely a half-inch of precipitation. Many locations across Maryland have seen even less. I've recorded just 0.02 inch on my backyard weather station since Aug. 27.  The USGS streamflow maps are showing more and more oranges and red as creeks dry up. The latest Palmer Drought Index maps show parts of Maryland - though not yet Central Maryland - are already experiencing moderate to severe drought conditions.

With no more rain in sight, September is beginning to look like a very dry month. The last time a September has looked this bad was in 1986, when the airport recorded just 0.58 inch. On the other hand, perhaps Rita will come ashore (with minimal effect, we hope), swing around and sweep across the U.S. with some serious rain. That's usually how these autumn dry spells end - with a tropical storm or its remnants. We can hope.

Posted by Frank Roylance at 10:38 AM | | Comments (0)
Categories: Drought

Rita now a hurricane

The National Hurricane Center this morning upgraded Tropical Storm Rita to a Category 1 hurricane, with top sustained winds above 73 mph.  Here is the most recent advisory on the storm, which is expected to pass over the Florida Keys today.Here is the predicted storm track, which might suggest that New Orleans and the storm-wracked Gulf Coast towns in Louisiana and Mississippi will be spared.

But when you look at the probability map for tropical storm-force winds, things get a little dicier for the Big Easy. The chances for TS winds (39 mph or higher) are between 20 and 30 percent - about one chance in four. That's why public officials there are so nervous this morning. Weakened levees and the city's hard-pressed pumping system won't be able to handle heavy rains and a sizable storm surge. So, Mayor Nagin has ordered everybody out of the pool. Again.

Here's the view from space as the sun was rising today over the Gulf. Here are the sea surface temperatures. They show the Gulf is still close to 30 degrees Celsius, which translates to 86 degrees Fahrenheit - more than enough to fuel Rita's growth. Forecasters expect her to reach Category 3 after she clears the Straits of Florida. That means top sustained winds in excess of 111 mph.

The National Hurricane Center told me last night that Katrina had sapped the Gulf of some of its warmth, leaving less fuel for Rita. But the storm will pass over what they call the Gulf's "loop current."  That's the deep river of warm water that flows out of the Caribbean, through the straits between Mexico's Yucatan Peninsula and Cuba, loops around the Gulf, through the Florida Straits and up the East Coast as the Gulf Stream. It's a very deep current, and a continuing source of heat for Gulf storms. So there's still plenty of room for Rita's development. And no matter where she goes ashore, the damage will be significant.

Posted by Frank Roylance at 10:10 AM | | Comments (1)
Categories: Hurricanes

September 19, 2005

Is this crazy, or what?

Not only are the Florida Keys and the Gulf Coast states once again facing a deadly encounter with a hurricane - Rita - but there is another storm, Phillipe, swirling harmlessly in the Atlantic, and THREE spinning like pinwheels across the Eastern Pacific.

Here are Rita and Phillipe. And here are Jova, Kenneth and Max.

The tropical seas are hot this summer, and we're seeing the results. Scientists say they've seen more of the most powerful Category 4 and 5 storms world-wide in the last 35 years, but no clear pattern of increase or decrease in the NUMBER of hurricanes. That's "not inconsistent" with the predictions of global warming theorists, they say. But they insist they have too little data to be sure whether human-induced global warming is at work here.

What do you think?  Post a comment and let it all out.

Have we brought this on ourselves? What, if anything, should we be doing to make things right? Or, is this just Nature doing what she has always done, except that we now have more people and property in her way? Should property owners be allowed to rebuild on the Gulf Coast beachfront? And if so, should state and federal taxpayers continue to pay the tab for rebuilding the coastal infrastructure - the water, sewer and roads needed to serve them?

Posted by Frank Roylance at 7:40 PM | | Comments (0)
Categories: Hurricanes

Rita threatens Keys, Gulf Coast

With Louisiana still staggering from Katrina, the last thing they need is another hurricane. But worries are mounting that Tropical Storm Rita, now bearing down on the Florida Keys, will reach hurricane strength soon and become an even greater threat as it enters the extremely warm waters of the Gulf of Mexico. That's Where Katrina blew up into a 175-mph Category 5 hurricane before crashing ashore as a Cat. 4.

The storm track looks for now like it will carry the bad weather further west than Katrina's landfall, toward the Texas coast. But forecasters are fretting over a possible turn northward as surrounding weather systems begin to shift. Here's the strike probability forecast. Almost any amount of tropical rainfall and storm surge would surely tax and threaten New Orleans' fragile levee repairs and emergency pump system.

Here is the latest advisory. Here is the storm track. And here is the view from space.

Posted by Frank Roylance at 3:50 PM | | Comments (0)
Categories: Hurricanes

September 16, 2005

Sunday: Space Station and Harvest Moon

Put this on your weekend to-do list: The International Space Station will fly high over the Mid-Atlantic states Sunday evening, giving taxpayers and stargazers another good look at their $80-billion-or-whatever-it-is investment.

The space station is orbiting the planet once every 90 minutes or so, zipping along at 17,500 mph and 230 miles above where the rest of us live. There are two people on board, Commander Sergei Krikalev and Flight Engineer John Phillips, referred to by NASA as Expedition 11. They're due for replacement Sept. 30 when a Russian Soyuz spacecraft stops by with a fresh crew. They'll land Oct. 10.

The weather forecast looks promising, with "mostly clear" skies predicted. Here's what to do:

The station will first appear above the northwest horizon at 8:08 p.m. EDT, moving briskly toward the southeast. It will look like a steady white star. If it has colored lights or a winking strobe, it's an airplane. Keep looking. At 8:11 p.m., it will be about 60 degrees above the western horizon. That's about two-thirds of the way from the horizon to the zenith - the point right over your head.

Moving swiftly toward the southeast, the station will disappear at 8:13 p.m. as it flys out of the direct sunlight and into the Earth's shadow. There's a bonus - a full Harvest Moon just rising in the east.

These flyovers are fairly common. But many are in the morning before dawn and not very enticing for people who like to sleep in; or the visible track is so close to the horizon, or so brief, that it's not worth the effort. This pass is relatively long, bright and due at a convenient time. And the weather should cooperate.

You can get flyover predictions for your locations anytime by visiting  Just register (or simply click on "select"), and follow the instructions for entering your location. In addition to satellite flyover predictions, there is a wealth of information for backyard stargazers.

Posted by Frank Roylance at 3:07 PM | | Comments (0) | TrackBacks (1)
Categories: Sky Watching

Watching the tropics and Martha's Vineyard

The National Hurricane Center is watching an area of stormy weather far out in the tropical Atlantic that could become the season's next tropical depression, and later a tropical storm. If so, it would be named Phillipe, the 16th tropical storm of the season. The experts have forecast between 18 and 21 for the season.

In the meantime, Ophelia continues to pull, slowly, away from the Carolina coast today. All tropical storm warnings there have been dropped. It's all about the cleanup now. But the tropical storm warnings are posted now from Watch Hill, Rhode Island to Plymouth, Mass., including Cape Cod, Martha's Vineyard and Nantucket. That means those folks can expect winds topping 39 mph within the next 24 hours. The probability map seems to put the risk at about 40 percent. Here's the forecast for Edgartown, on the Vineyard. Batten the hatches.

Here's Ophelia's forecast track. And a view from space.

Posted by Frank Roylance at 11:35 AM | | Comments (1)
Categories: Hurricanes

September 15, 2005

NASA images of Katrina damage

Here's an amazing gallery of images - including many before-and-after shots taken rom space and from aircraft - of the damage caused by Hurricane Katrina.  Look for links to even more galleries, like this one.

Posted by Frank Roylance at 11:41 AM | | Comments (1)
Categories: Cool pictures

Comet Tempel 1

Here's the most striking and detailed image of Comet Tempel 1 I've seen so far, shot by NASA's Deep Impact spacecraft in July. The mission, led by scientists at the University of Maryland at College Park, sent a 700-pound projectile to smash into the comet, allowing astronomers to study material from the comet's interior as it was blasted into space by the impact. 

Posted by Frank Roylance at 11:16 AM | | Comments (0)
Categories: Cool pictures

Ophelia from space

NASA's Terra Earth-observing satellite snapped a nice color picture of Ophelia yesterday, showing the storm's position relative to Maryland. We're clearly under her influence. Just click on the image to enlarge it. Thanks to the Smog Blog folks at the University of Maryland Baltimore County.

Posted by Frank Roylance at 11:06 AM | | Comments (0)
Categories: Cool pictures

Into some lives, a little rain

It still hasn't rained on my gauge in Cockeysville. But BWI did pick up another .27 inch around breakfast time today. That makes a half-inch on the nose for the month - all in the last two days, and courtesy, it appears, of Hurricane Ophelia. It's the first rain we've at the airport seen since Aug. 28.

The forecast holds out hope for a bit more over the next few days, as Ophelia makes her way up the coast, and a cool front approaches from the west.

In the meantime, the scarcity of rain seems to have had some beneficial effects on bay grasses and the aquatic life they sustain in the Chesapeake Bay - at least in the Susquehanna Flats near Havre de Grace. See Candy Thomson's report in today's Sun.

Posted by Frank Roylance at 10:47 AM | | Comments (0)
Categories: Drought

September 14, 2005

Ask Mr. WeatherBlogger: Where's the rain?

Heather Moyer writes from Columbia:

"I love reading the Baltimore Sun weather blog. My question is this: is the state's rainfall amount below normal? I ask because it seems as if many of the trees and lawns are turning brown and looking stressed - at least where I live. Thanks!"

Thanks for writing, Heather. Yes, it's been very dry lately. In fact, until nearly a quarter-inch fell today, we had recorded no rain at all at Baltimore-Washington International Airport since Aug. 28 - more than two weeks ago. We're now about 1.5 inches short for the month. It's the first significantly dry month since May. I think we're all hoping for a little blast from Hurricane Ophelia. The forecast says we may get some.

Posted by Frank Roylance at 6:15 PM | | Comments (0)
Categories: Ask Mr. Weatherblogger

Storm tides on the Western Shore

A strong onshore wind from Hurricane Ophelia and a surge of water into the Chesapeake Bay are expected to cause unusually high tides Thursday - 2.5 to 5 feet above mean low low water. That could mean minor flooding on the Western Shore of the Bay, according to the  National Weather Service. Here is the advisory. It should be nothing like the coastal flooding that accompanied Hurricane Isabel two years ago this weekend. But don't turn your back on this one.

High tide at the Inner Harbor is at 5:03 p.m.; Annapolis at 3:24 p.m.

Posted by Frank Roylance at 4:17 PM | | Comments (0)
Categories: Forecasts

Northern Lights tonight?

Ophelia's storm clouds will likely spoil the view for most Marylanders, but if you're far enough north or west and out from under the hurricane's cloud deck, you may get a chance to see the Northern Lights tonight. Here's a look at the clouds, from space.

More blasts yesterday from active sunspots crossing the sun's disk have sent clouds of solar particles and magnetic energy speeding toward the Earth. They are expected to begin interacting with the planet's atmosphere as soon as tonight, producing displays of Northern Lights. You'll need clear, dark skies and a view of the northern sky. You can read more about it by clicking here.

It's been an active week on the sun. Lots of folks around the world have been snapping photos of the Northern Lights for days. Here's a gallery of their work.

Posted by Frank Roylance at 12:53 PM | | Comments (0)
Categories: Science

Ophelia spins up to 85

Top sustained winds near Ophelia's center have picked up to 85 mph, according to Hurricane Hunter aircraft. The storm was centered 85 miles southwest of Pt. Lookout, NC. Here's the latest advisory. Here's the latest track prediction, which shoots the storm off the Outer Banks and out into the Atlantic. Here's how she looks from space.  Those clouds out on the storm's northern fringe must not be very dense. The sun's out again in Baltimore.

Posted by Frank Roylance at 12:35 PM | | Comments (0)
Categories: Hurricanes

We feel ya

After weeks of clear, dry skies, Marylanders are finally feeling the outer reach of Hurricane Ophelia. The clouds and tropical humidity moved in over night, and there were even a few sprinkles in the air this morning. Here is a satellite view that clearly shows the storm clouds that have overspread the region.

The storm has also strengthened during the night. Its top sustained winds are now blowing at 80 mph. Here is the latest advisory from the National Hurricane Center. Here is the latest storm track forecast. The tropical storm watches extend northward to the mouth of the Chesapeake Bay. Baltimore should start feeling some wind and perhaps more rain by this afternoon. But there is only a slim chance - less than 10 percent - Baltimore will feel any tropical storm-force winds. The worst of this storm seems fated to brush through the Outer Banks and accelerate out to sea without setting foot in Maryland. The weekend looks fine.

Posted by Frank Roylance at 9:37 AM | | Comments (0)
Categories: Hurricanes

September 13, 2005

Ophelia a hurricane again

Hurricane warnings have been extended northward to Cape Hatteras after hurricane spotter aircraft this afternoon found sustained winds at the storm's center of 75 mph, with higher gusts. That makes the storm a hurricane again. Here is the latest advisory. Here is the latest storm track. And here is the view from space.

Tropical storm warnings and hurricane watches are now posted as far north as the North Carolina/Virginia border. The tropical storm watches reach to the mouth of the Chesapeake Bay.

Wrightsville Beach, NC looks pretty stormy in this beach cam shot.

Ocean City, MD still looks great in this one. Wish I were there.

But I'm not. I'm stuck here in town, but at least we have little to worry about locally from the storm. Here is the Special Weather Statement from the folks at Sterling for the Baltimore-Washington region.

Posted by Frank Roylance at 5:26 PM | | Comments (0)
Categories: Hurricanes

Hot, but no record

Sure, it was 88 degrees at Baltimore-Washington International Airport yesterday. And it's 88 today and could go higher. But it's still officially summer for 10 more days, and there have been plenty of September days that have been hotter. The record for Sept. 12 is 96 degrees, set back in 1931. And the record for Sept. 13 is 97 degrees, set back in 1952. In this case, our elders really DID have it worse.

Posted by Frank Roylance at 2:11 PM | | Comments (0)
Categories: By the numbers

Waterfront interests watching Ophelia

Wind and waves, and minor flooding on the western shore of the Bay are all in the cards for Marylanders as Tropical Storm Ophelia approaches landfall in the Carolinas. The National Weather Service has posted a Marine Weather Statement for the Chesapeake. It says small-craft advisory conditions are expected late Wednesday and Thursday. With a slight twitch in the storm track, minimal tropical storm winds (39 mph) could develop in the lower part of the Bay, with gusts and heavy squalls. High tides could also cause minor flooding on the western shore.

Strong onshore winds that could reach tropical storm force will also mean rough surf and coastal flooding for Marylanders at the beaches, according to a Special Weather Statement issued today.

Here is the latest Ophelia advisory from the National Hurricane Center. Here is the latest storm track.  And here is the view from space. And another view, in color; just click on the image.

Posted by Frank Roylance at 10:21 AM | | Comments (0)
Categories: Hurricanes

September 12, 2005

What if we run out of names?

With Tropical Storm Ophelia menacing the Carolina coast, we're struck by how many of the season's 21 storm names we've run through this year.  Ophelia is the 15th named storm of the season. There are just six more names on the list: Phillippe, Rita, Stan, Tammy, Vince and Wilma. After that, the National Hurricane Center will have to turn to the Greek alphabet: Tropical Storms Alpha, Beta, Gamma, Delta and so on. It's never happened before. But then again, we're just halfway through the season, and 71 percent of the way through the name list.

We've reached the letter "O" in the Atlantic hurricane season four other times during the current more-active cycle of tropical Atlantic storms, which began in 1995. That first year, 1995, was a whopper, with 19 named storms. The last one named that year was Tanya. (Forecasters this year are predicting 18 to 21 named storms. Those numbers were posted in August after the experts revised their May forecast for 12 to 15 named storms in light of the season's extraordinarily busy start.)

The "O" storms of the current cycle have always arrived much later than this. (Click here for the archives.) Ophelia earned her name on Sept. 7.

The "O" storm in 1995 was Opal, which formed on Sept. 27 and lasted until Oct. 5. The 2001, 2003 and 2004 seasons also reached "O" or beyond. The last storm in 2001 was Olga (Nov. 24 - Dec. 4). (The Atlantic hurricane season ends Nov. 30, but storms don't always play by the rules.)

In 2003 we got all the way to Peter. The "O" storm that year was Odette, a real late-bloomer (Dec. 4-7). And last year the final named storm was Otto, which formed Nov. 29 and faded away Dec. 3.

On the other hand, hurricane specialists say they're also running out of storm systems in the Atlantic. It could be the end of the season. Or, it could be a lull.

Posted by Frank Roylance at 5:16 PM | | Comments (2)
Categories: Hurricanes

Solar storm triggers Northern Lights

Some of the biggest solar storms ever recorded ripped through the solar corona late last week. The results were evident in the skies over northern states yesterday. Here is a gallery of images shot by photographers from North Dakota to Cape Cod. The large sunspot group responsible for the violence is rotating across the sun's disk, and could blast additional matter and energy our way in the coming days, producing more Northern Lights. We're not in the best position to see them in Maryland. But if they're strong enough, we might. The best time to look is local midnight. Get away from city lights and look toward the north. Eyeballs are best.

And while you're out there, get a load of Mars, (scroll down to "planets" and then "Mars") which is getting bigger and brighter each night as we approach opposition in late October. The Red Planet is now rising in the east at about 10 p.m. You can't miss it.

Posted by Frank Roylance at 12:27 PM | | Comments (0)
Categories: Sky Watching

Ophelia, we may feel ya

The National Weather Service says Maryland may feel the fringes of Tropical Storm Ophelia after she brushes by the Outer Banks around mid-week. Here's the statement. The forecasters at Sterling have also posted small craft advisories on the Chesapeake, and in coastal waters from Fenwick Island, Del., south to the Carolinas.

The National Hurricane Center downgraded Hurricane Ophelia to tropical storm status again today after spotter planes clocked its highest sustained winds at about 70 mph. But it may be just a technicality. The storm is expected to continue to move toward the Carolina shores, and could well regain hurricane status later today. It's a distinction without a difference at this point. Ophelia is fluctuating between about 70 mph and 75 mph - a meaningless difference if you're in the storm's path. But the rules of the Saffir-Simpson Hurricane Scale say top sustained winds of 73 mph makes a tropical storm, but at 74 it becomes a hurricane.

Whatever. Here is the latest forecast track, as best they can figure it out. Tropical storm warnings and hurricane watches are posted from South Carolina north to Point Lookout, N.C. And here is the view from space. That's a good-looking storm.

Posted by Frank Roylance at 11:12 AM | | Comments (0)
Categories: Hurricanes

Rain, maybe, at mid-week

There's a slight chance we'll get some relief from this mini-drought by late Wednesday. But don't bet the lawn on it. Forecasters are thinking that, with Hurricane Ophelia expected to pass to our southeast, and a weak cool front due to move through at mid-week, we may get a little rain from one or the other. Or both. But it's only a slight chance. Here's their discussion:



We could sure use some moisture. The airport has recorded no precipitation at all since Sunday. Aug. 28.  That's 15 days ago. A number of area streams are slipping into below-normal categories, including Savage Run near Barton, Md.; the Jones Falls at Sorrento; and Winter's Run in Harford County.

It's beginning to look like the 20-day dry stretch we saw in June. Between June 7 and June 26, the airport recorded only 0.2 of an inch of rain. On the other hand, what a gorgeous weekend. The sunny, dry days and cool, starry nights have made it easy to ignore the straw in my yard that passes for grass. Is anybody complaining ?

Posted by Frank Roylance at 10:45 AM | | Comments (0)
Categories: Forecasts

September 9, 2005

Perfect weather, unless you're a plant

Still no rain or clouds in sight. The days will remain sunny and dry right into next week, continuing a glorious stretch of fine late-summer weather. Think of it as paybacks for all the the humid, 90-plus days in August and July.  But lawns are getting brown. We've had no rain at all this month at BWI.  In fact, the last we had was on Sunday, Aug. 28 - twelve days ago.

You can thank Canada for our good fortune. But the high-pressure system to our north is moving out, and more high pressure from the southwest is moving in. The weather will stay fair, but it will get hotter early next week - 88 - well above normal for this time of year.

Posted by Frank Roylance at 6:50 PM | | Comments (0) | TrackBacks (1)
Categories: Forecasts

Ophelia a hurricane again

Ophelia is a hurricane again after being demoted to tropical storm overnight. She now has top sustained winds close to 75 mph. And forecasters warn it could become a threat again to the coast from Florida to the Carolinas. Here is a color satellite photo of this oddball storm, which developed close to the Florida beaches and reached hurricane strength there twice without ever coming ashore.

The National Hurricane Center is predicting the storm will take a weird left hook toward the coast in the coming days. Here's the forecast track. Here's the latest advisory.

Posted by Frank Roylance at 6:23 PM | | Comments (0)
Categories: Cool pictures

September 8, 2005

Ophelia haunts Fla. coast

After spinning off the east coast of Florida all week, gradually gaining strength, Ophelia finally became a hurricane today. The storm is the seventh of the season to reach hurricane strength, with top sustained winds nearly 75 mph. It continues to idle off the east coast of Florida, about 75 miles north northeast of Cape Canaveral.  Its hurricane winds are fairly limited in breadth, so no hurricane warnings have been posted yet on shore. The storm is expected to strengthen, but seems likely to move slowly north and east, avoiding a continental landfall.

Here is the storm track. And here is the view from space. This one, too, looks like a miss.

Posted by Frank Roylance at 6:23 PM | | Comments (0)
Categories: Hurricanes

Cool morning at BWI

The mercury at Baltimore-Washington International Airport dropped to 52 degrees early this morning. It's no record. The low mark for a Sept. 8 in Baltimore is 46 degrees, set back in 1962. But it's the coolest it's been at the airport since June 20, and a harbinger of what's ahead.

It was colder elsewhere. The instrument on my back deck in Cockeysville read 48 this morning.  It was 45 in Frederick and 47 in Martinsburg, W. Va.

Posted by Frank Roylance at 10:10 AM | | Comments (0)
Categories: By the numbers

All clear ahead

Whatever bad things must be said about Hurricane Katrina, Marylanders, at least, have had nothing but spectacular weather since her remnants passed through last week. And the forecast holds nothing but the finest late-summer weather anyone could wish for. Clear, sunny skies, and starry nights are lined up as far as forecasters can see. Of course, the grass is drying out, and we could use some rain. But it sure has been beautiful. Enjoy. And be thankful.

Posted by Frank Roylance at 9:58 AM | | Comments (0)
Categories: Forecasts

September 7, 2005

Escape Earth's dismal weather news...

... and have a look at weather on Enceladus, a moon of Saturn, as photographed by NASA's Cassini probe now in orbit around the ringed planet. Or, if you'd rather not stray so far from home, here's a view from a mountaintop (Husband Hill) on Mars, climbed by NASA's intrepid Spirit rover. (If the Mars link has changed to something else, click on "Archive" and you'll find it there.)

Posted by Frank Roylance at 1:17 PM | | Comments (0)
Categories: Cool pictures

Tropical update

Overnight, Tropical Depression #16, which had been collecting itself in the northwest Bahamas, matured into a tropical storm. Dubbed Ophelia, it is now spinning about 85 miles northeast of Cape Canaveral, with top sustained winds of 50 mph. It is threatening the heavy rains and rough surf along the east coast from central Florida to the Carolinas. It continues to move slowly northward up the coast. Here is the latest advisory. Here is the storm track. And here is a satellite image. That's Ophelia hugging the Florida coast, Nate to the east.

Meanwhile, Bermuda residents are under a tropical storm watch. Tropical Storm Nate, now more than 200 miles south southwest of the island, strengthened today to hurricane force, with top sustained winds of 80 mph. Here is the latest advisory. Here is the storm track. And here is the view from space. (Nate is on the right)

Tropical Storm Maria also strengthened today to hurricane force. But at least it's not threatening any land mass. Hurricane Maria is now far out in the Atlantic, 1,300 miles west of the Azores. Its top winds are near 80 mph, and it is headed northeast at 14 mph. Here is the latest advisory. Here is the storm track. And here is the satellite photo. Maria is at the extreme upper right of the image, headed out of the picture, thank goodness. But it's a busy ocean in this photo.

Maria and Nate are the 5th and 6th hurricanes of the season. Hurricane forecasters in Miami are watching some stormy weather in the western Gulf of Mexico, but they say conditions there are not favorable for tropical storm development.

Whew! The good news - or maybe the bad news - is that the 2005 hurricane season is almost half over.

Posted by Frank Roylance at 12:28 PM | | Comments (0)
Categories: Hurricanes

September 6, 2005

A normal summer

The meteorological summer - the months of June, July and August - have ended with little departure from the long-term averages across the region. Click here for the National Weather Service's take on the late, great Summer of '05. BWI saw pretty nearly normal average temperatures, even with 27 days that topped 90 degrees. Rainfall was about 4 inches above the norm.

Here are the charts for June, July (which ended extraordinarily wet thanks to a 2.79-inch deluge at the airport in mid-month, and a tad hot, due to 12 days that hit 90 or more) and August at BWI, which was 3 degrees hotter than the long-term average.

Posted by Frank Roylance at 7:58 PM | | Comments (0)
Categories: By the numbers

Ask Mr. WeatherBlogger

Joyce writes to ask: "Could you explain the pressure to me? I have vestibular neurocity (a form of vertigo). When the pressure drops there is a real increase in my symptoms of light headedness and nausea. Storms send me to bed for days. For fun info, can you tell me the best and worst states to live in? I thank you so much!"

Thanks for the query, Joyce. You can think of atmospheric, or "barometric" pressure as the weight of all the air above your head pressing down on the Earth's surface - including people like you and me walking around on it. It's much like the pressure of water on the bodies of scuba divers as they descend to the bottom of a pool or a lake. The weight of the air pressing down on us at sea level amounts to about 14.7 pounds per square inch, or roughly a ton per square foot.

Fortunately, the pressure in our bodies pushing out is about the same as that pushing in, so we aren't crushed. But we can feel the change of pressure in our ears when we ride up or down on the elevators in tall buildings, or when we drive up or down mountain roads. The higher we get, the lower the atmospheric pressure.

When we're going down, there is more air pressing on our eardrums, and we feel a need to "clear" or "pop" our ears by swallowing or yawning. What we're actually doing is stretching our throats, allowing air at the increased pressure to enter our eustachian tubes, which lead from high in the back of our throats into our inner ears. That equalizes the pressure on the inside and the outside of our eardrums.

The same thing happens in reverse when we go up the elevator. The atmospheric pressure on the outside drops, and the pressure of air in our inner ears becomes higher than that of air on the outside, and it presses against our eardrums. When we yawn or swallow, the air escapes and the pressure is relieved.

Weather systems are much slower than elevators, but they have a similar effect. Where atmospheric pressure is low, the weather becomes stormy. Clear, sunny weather comes with high pressure systems. Scientists have long noted the link between changes in atmospheric pressure and physical symptoms, such as arthritis and Meniere's disease. So you're probably not imagining it, especially since our inner ear is where our balance control mechanisms are located. When something affects those balance centers, we can experience vertigo, nausea and similar symptoms. 

If you think your symptoms get worse is stormy weather, it might make sense to live somewhere where the weather is clear and dry, and atmospheric pressure typically is high, perhaps in the Southwest. High-altitude states like Colorado would appear to be out, however, as would stormy places like Seattle. Far-northern places like Canada or Alaska might work. Cold air is dense air, which is also heavier. Some of the highest atmospheric pressures ever recorded have been in far northern regions. Ideally, though, I guess what you're looking for is a relatively comfortable coastal desert. Maybe Lima, Peru or Casablanca, in Morocco.

Posted by Frank Roylance at 11:39 AM | | Comments (2)
Categories: Ask Mr. Weatherblogger

Maria, Nate and now Ophelia??

The tropics haven't rested over the long Labor Day Weekend. Tropical Storm Maria became the 5th hurricane of the season early Sunday morning, and spun up to more than 100 mph by Monday morning. It has since weakened somewhat as it drifts north and east in the open Atlantic 500 miles northeast of Bermuda. It's a threat only to shipping. Here is the latest advisory. Here is the storm track. And here is a satellite image. (It's the spiral in the upper right-hand corner of the photo.)

Meanwhile, the 15th tropical depression of the season formed about 350 miles south southwest of Bermuda. By Monday night it had become Tropical Storm Nate, the 14th named storm of the 2005 Atlantic season. It was 275 miles south southwest of Bermuda this morning, blowing at about 60 mph. It could threaten Bermuda by week's end, but is a threat only to shipping for now. Here is the latest advisory. Here is the storm track. And here is a satellite image. (The swirl at upper right-center.)

The latest addition to the Class of 2005 is a new tropical depression that formed this morning in the northwest Bahamas, the 16th tropical depression of the 2005 season. And if it makes it to tropical storm strength later today, would become TS Ophelia. It poses a threat this week to the east coast of Florida, where as much as 15 inches of rain is possible. Here is the latest advisory. Here is the storm track. And here is a satellite image.

Here is the fast-dwindling list of names for this season.

Posted by Frank Roylance at 11:04 AM | | Comments (0)
Categories: Hurricanes

September 2, 2005

All clear ahead, for Maryland

When was the last time Baltimore saw a forecast like this one. Clear, sunny, clear, sunny ... as far as the eye can see. Have a great Labor Day weekend, remember the people suffering as a result of Hurricane Katrina, reach into your pocket and do what you can for them. The ordinary comforts of home suddenly don't seem so ordinary any more, do they?

Posted by Frank Roylance at 6:07 PM | | Comments (0)
Categories: Forecasts

New Orleans flooding, from space

The floodwaters that gushed from Lake Pontchartrain into New Orleans and other surrounding communities during Hurricane Katrina are clearly visible in this shot, taken from orbit on Tuesday by NASA's Terra Earth observing satellite. Another photo shows what it looked like before the hurricane.

Posted by Frank Roylance at 5:58 PM | | Comments (0)
Categories: Cool pictures

New tropical storm forms

The National Hurricane Center today reported the formation of the 2005 season's 13th named tropical storm, far out in the Atlantic Ocean. Her name is Maria, and fortunately for everybody she does not appear to be a threat to land.

Here is the latest advisory. Here is the predicted storm track. And here is a satellite image. (It's the fuzz-ball at center-right.) The swirl to its north is the remains of Tropical Storm Lee, now a dissipating tropical depression.

Next up: Nate

Posted by Frank Roylance at 12:03 PM | | Comments (0)
Categories: Hurricanes

September 1, 2005

September promises a cooloff

September arrived today with a promise of cooler weather. The average daily high temperatures at Baltimore-Washington International Airport drop from 82 degrees to 73 degrees during the course of the month. The average overnight lows sink from 61 to 51 degrees. Windows open, air conditioning bills go down, and summer ends. The Autumnal Equinox occurs this year at 6:23 p.m. on Thursday, Sept. 22.

That's not to say we can't still have some very hot days. The record daily highs run from the low 90s into the 100s this month. The hottest September day on record in Baltimore was Sept. 7, 1881, when the mercury reached 101 degrees. But it can also get pretty cold. The coldest was Sept. 25, 1963 (almost two months before President Kennedy was shot), when the thermometer at the airport sank to 35 degrees.

Average precipitation in September at BWI is 3.98 inches, according to the National Weather Service. It has never snowed here in September since record-keeping began in 1871. (We can't say that of October.) The wettest September was in 1934, when 12.41 inches fell in Baltimore. The driest was 50 years earlier, when only nine hundreths of an inch was recorded.

Posted by Frank Roylance at 10:51 AM | | Comments (0)
Categories: By the numbers
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About Frank Roylance
This site is the Maryland Weather archive. The current Maryland Weather blog can be found here.
Frank Roylance is a reporter for The Baltimore Sun. He came to Baltimore from New Bedford, Mass. in 1980 to join the old Evening Sun. He moved to the morning Sun when the papers merged in 1992, and has spent most of his time since covering science, including astronomy and the weather. One of The Baltimore Sun's first online Web logs, the Weather Blog debuted in October 2004. In June 2006 Frank also began writing comments on local weather and stargazing for The Baltimore Sun's print Weather Page. Frank also answers readers’ weather queries for the newspaper and the blog. Frank Roylance retired in October 2011. Maryland Weather is now being updated by members of The Baltimore Sun staff

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