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April 30, 2009

April showers bring May ... showers

Look at this forecast. Nothing but clouds and showers (and maybe a thunderstorm thrown in for tomorrow) for the next seven days. Only on Wednesday of next week do we begin to see the word "sun" or "sunny" in the mix.

Sun Photo/Rachel J. Golden 2000Oh, sure. We do still need rain. The entire state remains "abnormally dry" on this morning's Drought Monitor Map. The dryness is hydrological, meaning that, thanks to recent rains, agriculture appears to be off the hook for now, but dry conditions continue to trouble water tables and wells. But it is a signal that we do really need more substantial rain - more than would appear to be in the offing in the next week from the "chance" of showers in the forecast.

Temperatures after today will remain around the long-term averages for this time of year in Baltimore - around 70 during the day. Nights will be a bit warmer than the norms, in the 50s.

The exceptions will be today, where we will once again struggle to reach 60 degrees. Yesterday's high was 71 degrees, reached right after midnight. After falling out of the 70s around 2 a.m., we dropped to 53 by 9 a.m. and stuck there, never rising above 56 degrees all day. The overnight low was 50 at BWI. And the forecast high today is only 59 degrees.

The problem is high pressure over southern New England, which is blocking warmer weather from the west, and sending cloudy, cool, damp air at the surface back into the mid-Atlantic states.

On Friday we'll catch a bit of a break, as the high drifts away, and the cold front to our south returns as a warm front, and afternoon highs climb to the mid-70s. That could come with some thunderstorms. But the frontal boundary will be back, stalling across the region for the rest of the weekend and well into next week. From then on, we're looking at cooler, "mostly cloudy" days with "a chance" for showers.

So, maybe it's a good weekend to get the gardening done. But replacing the roof, or working on that pasty winter pallor? Maybe not so much.

Posted by Frank Roylance at 10:12 AM | | Comments (0)
Categories: Forecasts
        

April 29, 2009

From the clouds to your tap; water isn't free

It may start free, but almost as soon as the rain hits the ground, it begins to cost money. The Baltimore Department of Public Works has to capture that water, protect its purity, process it, ship it to your spigot and send the sewage off for treatment.

The folks in Baltimore who make sure that water reaches the millions of people who rely on it have their hands full, especially when this old city's aging pipes begin to crack, as they have so spectacularly this week.

So maybe this is the perfect time they tried to educate the public about the often invisible work they do. May 3 to 9 is National Drinking Water Week, and the Baltimore DPW had organized a full week of activities designed to showcase the water system that produces what is arguably the tastiest and most reliable - even in drought - municipal water of any big city in the Northeast.Sun Photo/David Hobby 2005

The week kicks off Sunday from 10 to 3 at Loch Raven Reservoir, where you and the kids can learn about where the city's water comes from, and the history of the valleys and the dams and the three reservoirs that now capture and store the city's water. There's also plenty to know about the critical role we all play in making sure the watersheds that feed these reservoirs stay clean - for us and for the wildlife and the fishery that share the land and water with us.

On the 4th, at noon, there will be an event at the Ashburton Water Treatment Plant (3001 Druid Park Drive) that includes dedication of the renovated atrium, and a screening (5:30 p.m. at the Maryland Science Center) of the documentary "Liquid Assets," describing the water and wastewater systems that keep us all healthy and hydrated.

On Friday, May 8, 12:30 to 2:30, the DPW's water and wastewater employees will be honored at an "Employee Appreciation Event at the Haven Street Maintenance Yard, 804 N. Haven St. These are the guys who repair those pipes, getting wet and muddy in sometimes freezing conditions to keep the fluids flowing under the streets.

Finally, on Sunday May 9, from 10 a.m. to 2 p.m., the public is invited to tour the Montebello Water Filtration Plant 1, at 3901 Hillen Road. Learn how our water system operates, and how the mains are repaired, replaced, cleaned and re-lined. 

Sun Photo/Kim HairstonIt's a tough, expensive job, but someone's got to do it. And, of course, someone's also got to pay for it. So when the city asks for a (another) water rate increase (9 percent) later this year, at least you'll know where the money goes. The proposed hike amounts to $74 a year for a typical family of four using 39 units of water each quarter.

The new rates would mean we would pay five cents for a 10-minute shower. The increase would bump Baltimore from the second-cheapest water and sewer rates to fourth, out of seven nearby jurisdictions. The annual costs for a family of four are now the cheapest of seven eastern cities, the city argues. The increase would bump us to second, leap-frogging New York City, but still cheaper than Philadelphia, Washington, Richmond, Boston and Atlanta.

The money is needed, the city argues, in order to rebuild and replace aged water and sewer lines, and to tackle the rising number of main breaks being reported - 5,000 between January 2005 and January 2009 alone. Leaks cost us all 20 percent of all the water the city processes. Work in the queue includes $2.2 billion in capital improvements to the system.

Posted by Frank Roylance at 3:21 PM | | Comments (4)
Categories: Events
        

Heat? What heat?

NOAA

Today's radar loop shows very clearly the passage of the cold front this morning. The front, as promised, has swept away the premature summer heat that sent temperatures into the 90s this week. It has also introduced what will be a long stretch of damp but cool (or seasonable) weather for Central Maryland.

The forecast out of Sterling this morning shows showers, a chance for rain or thunderstorms right through the weekend. The coolest day will be today, with highs struggling to reach 60 degrees. The warmest is Friday, with a maximum at BWI near 78 degrees. Nights will be great for sleeping, with lows from 46 degrees (tonight) to the 50s for the rest of the period.

At least we'll be burning very little energy for either heat or cooling.

We end the week with a couple of remarkable numbers on the books. First, three straight April days in the 90s, something that has happened only three times before - in 1929, 1960, and 1976. It was 90, 91 and 91 again on April 25, 26 and 27, respectively. None of those highs tied or broke records, but they came close.

Second, Steve Zubrick, the science officer out at Sterling, points out that this week's spate of 90-degree highs came before BWI had seen any daily maxima in the 80s. That's happened just twice before, he says, on April 27, 1969 and April 20, 1927.

We finally topped out in the 80s on Tuesday, with a high at BWI of 87 degrees.

Amazing.

 

Posted by Frank Roylance at 10:33 AM | | Comments (3)
Categories: Forecasts
        

April 27, 2009

Three straight in the 90s; an April rarity

Once again the thermometer surged to 91 degrees at BWI, but once again it lacked the oomph to break past that mark and tie the record for the date - 92 degrees on April 27, 1994.

The same thing happened yesterday. We made it to 91 at BWI, but fell short of the record for that date - again 92, set on April 26, 1990.

But we did notch up a third April day in a row in the 90s today. It's only the fourth time since records began in 1871 that's happened, according to Steve Zubrick, science officer at the National Weather Service forecast office at Sterling. The previous occasions were in 1976 and 1929, and in 1960, when we managed to string together FOUR straight days in the 90s - April 23-26, 1960.

Tuesday's forecast high is 88 degrees. The record for the date is 90, set in 1957. 

It was 93 at the Inner Harbor today, by the way. And we reached 96 degrees here at The Sun.

Dunno. I may be forced to switch on the AC tonight to cool down the house. Anybody else out there still keeping hands off the thermostat? Hot as it's been, the nights have been cool. By morning under an open window it's been quite chilly.

At least it's dry. The relative humidity here at Calvert & Centre is only 27 percent.

Posted by Frank Roylance at 5:52 PM | | Comments (13)
Categories: By the numbers
        

Allergies acting up? Blame a tree

You can see it, plain as day, on your car. That greenish-yellow powder is pollen, mostly from trees at this time of year. And I'd guess mostly oaks.

Pollen counts are high. And if you suffer from spring allergies, you probably didn't need to beSun Photo/Amy Davis told. The outdoors is all in bloom, and the trees, especially, are performing their version of courtship and mating, sending out clouds of male pollen in search of female flower parts. And until they get the job done, or we get a good soaking rain, we'll be dealing with tree pollen allergies.

If you'd like to check the daily pollen counts, here are a couple of Web sites that may help. Pick your fave and check it daily.

The American Academy of Allergy Asthma and Immunology.

The Weather Channel.

WeatherBug.

 

 

Posted by Frank Roylance at 2:01 PM | | Comments (0)
Categories: Air quality
        

The heat can't last

Hang in there, Maryland. This premature high-summer weather can't last. The 90-degree temperatures will expire after today. We'll have one more warm day, and then everything will return to normal. Here, below, is how we looked Sunday from orbit, as we basked in the sunshine.

Maryland DNR/MODISBy Wednesday we'll be back in the low 70s, and Thursday will stall out in the low 60s as the next cold front slips by and stalls to our south. That will be a 30-degree drop in daytime highs, and it will also bring us better chances for showers for the rest of the week.

In the meantime, however, we'll have to contend with the heat. After threatening a record high yesterday (we fell short at 91 degrees at BWI - a degree short of tying the record), we're headed for a high of 91 again today if the forecast holds up.

As wind gusts pick up this afternoon, meteorologists are warning that the effects of heat and drying humidities (37 percent relative humidity in Baltimore at last check)will elevate the dangers of wildfires. The "enhanced fire threat" will continue from late Monday morning until early Monday evening. "If you plan to burn, please check with your local authorities before doing so," the weather service advised.

Once again, this April heat wave comes to us courtesy of the big high-pressure system still spinning off the Carolina coast. Circulation around all highs is clockwise, so we are getting winds out of the southwest and west. Already dry, these breezes are dried further and heated as they sweep down the eastern slopes of the Appalachians. And we see 90-degree readings.

We reached 91 degrees yesterday out on the WeatherDeck in Cockeysville, and 94 degrees at The Sun's weather station at Calvert & Centre streets. We're at 87 degrees here now, at about 11:30 a.m. You can check the newspaper's readings anytime. It's updated every 10 miniutes, day and night. Click here and save the link to your desktop

Although many April dates (18 in all) have record highs in the 90s, multi-day stretches of 90-plus weather like this are pretty unusual, according to Steve Zubrick, science officer for the National Weather Service's Sterling forecast office. In fact, this is the first 90-degree April weather at BWI since 2004.

Steve tells me the longest sequence of consecutive 90-plus days in April at BWI is four days, set from April 23-26 in 1960. The highs were 94, 93, 94, 91 degrees.

Baltimore has recorded three-day spells in the 90s on two occasions, in 1976 and 1929.

Today we seem likely to add a third instance, with highs of 90 and 91 degrees on Satiurday and Sunday, plus a third mark in the low 90s today. Adding a fourth 90-degree day on Tuesday will be a bit harder. The official forecast is for a high of 88. But Steve thinks it's a real possibility. 

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

April 26, 2009

890 bird strikes reported in Maryland 1990-2007

In all the reporting in recent weeks about the bird strike data recently released by the Federal Aviation Administration, I never read anything specific to Maryland. But the report is now available online and it's available to anyone curious enough to plow through it.

It's fascinating reading, full of statistics and gory photos, including a shot of one expired bald eagle, snapped after he blasted through the windshield of a helicopter, knocking a passenger unconscious and forcing the pilot to land - safely, as it turned out.

If you never really realized that a fluffy, feathery bird could pose a mortal threat to big, aluminum airliners, get a load of the photos in this report. You'll be amazed by what happens to the leading edge of a Boeing 737's wing after being smacked by a blue heron.

The data include an accounting of reported wildlife strikes on aircraft, by state. It notes a total of 954 incidents in Maryland - not just BWI, one presumes - between 1990 and 2007. The tally includes 890 birds, 6 bats and 58 terrestrial mammals. Bambi strikes back!

Posted by Frank Roylance at 1:13 PM | | Comments (2)
Categories: Phenomena
        

April heat sticks until Wednesday

Temperatures reached a high of 90 degrees at BWI yesterday afternoon, and it looks like we're in for more of the same straight through Tuesday as we remain under the influence of a Bermuda high sitting off the Carolina coast. 

Yesterday's high at BWI did not challenge the 94-degree record for the date, set back in 1960. (Ninety-four is also the highest reading on record for April in Baltimore, matched on two days in April 1960, and once each in 1941 and 1896.)

We recorded a high of 86 degrees here at The Sun on Saturday. It's already 86 here as I write Sunday morning at 10 a.m. We had a high of 91 degrees out on the WeatherDeck in Cockeysville on Saturday.

NOAAHere are some other highs reported Saturday from across the region. (Easy to forget it was 29 degrees at BWI just 12 days ago, and that we recorded traces of snow there on April 7 and 8.)

Today's forecast out of the Sterling office calls for a high again near 90 degrees (that's the 5 p.m. temperature forecast map at left), but I'll be surprised if we don't exceed that number. The record for Baltimore on an April 26 is 92 degrees, set in 1990. I'll go out on a limb here and predict a record high at the airport this afternoon.

UPDATE: Nope. The high at BWI was 91 degrees, although we did reach 93 at the Inner Harbor. The forecasters had it right.

As air at the surface heats up, it will rise, drawing in cooler air from over the bay. That bay breeze should keep things cooler along the western shore. But it may also help to fuel pop-up thunderstorms west of I-95 like the one that boomed over Baltimore Saturday evening.  

Sunny and hot weather will continue through Tuesday, if the forecast holds up, with Monday's forecast high at 90 again, and only slightly cooler - 89 degrees - on Tuesday.

That's when the next cold front will finally start to press into the mid-Atlantic states. High, cirrus clouds will start to show up on Tuesday ahead of the front. By Wednesday, we should be looking at a chance of showers and thunderstorms, with highs only in the 70s. Winds shifting to the east will bring in cool, moist air. More chances for showers will persist into the weekend.

Posted by Frank Roylance at 9:47 AM | | Comments (0)
Categories: Forecasts
        

April 24, 2009

Sky show after sunset Sunday

If skies remain clear across Maryland, as they should, we may be able to catch an unusual gathering of celestial objects in the western sky after sunset on Sunday.

UPDATE: Here's a gorgeous shot of this event.

Sun Photo/Karl Merton FerronThe first of the crowd to appear will be a slender crescent moon, just above the western horizon about 45 minutes after sunset. Sunset for Baltimore on Sunday will be at 7:55 p.m. The moon will be barely 24 hours past "new," and just about as slim a sliver of moon as you will ever see.

Next, as the dusk continues to deepen, just below the moon, you should be able to see a tiny "star" pop into view. Binoculars will help while the sky remains fairly bright. It's not actually a star, but the always-elusive planet Mercury, which is about as far to the east of the sun this month as it gets, and therefore easiest to spot.

Now, as the darkness gathers, and the moon and Mercury sink closer to the horizon, watch immediately below the moon for a delicate cluster of stars called the Pleiades to appear. This star cluster is called Subaru by the Japanese. It's also known as the Seven Sisters because it appears to the unaided eye to contain seven stars in a close grouping. With binoculars, many more appear. In a small telescope, there are hundreds. They're all in a tight bunch, fairly close by astronomical standards - about 415 light years away. (One light year - the distance light travels in a year - is about 5.9 trillion miles.) 

The moon, by comparison, will be a mere 228,000 miles away on Sunday, while Mercury currently stands about 82.7 million miles from Earth. Here's the sky map, from NASA.

NASA

Posted by Frank Roylance at 4:40 PM | | Comments (0)
Categories: Sky Watching
        

Out of the 30s, into the 80s

Sun Photo/John Makely April 2006Ya gotta love April in Baltimore. Overnight lows this morning sank well into the 30s across a good deal of the region. There was a low of 37 reported from Towson, with minimums near the freezing mark above the Pennsylvania line and even lower elsewhere to our west. Here is a map of low readings from NWS observers.

And now the forecast is calling for a Baltimore high in the 70s this afternoon, climbing well into the 80s for Saturday through Tuesday. We haven't seen the 80s around here since Oct. 16, so it's going to feel HAWT!

The "normal" (actually, the long-term average) highs and lows for BWI at this time of year are in the mid-60s and mid-40s. But hot weather in April is not uncommon. We touched the 80s on three dates in April last year, and on five dates the year before. The records at this time of year are in the mid-90s and mid-30s.

We're enjoying the nice weather courtesy of a big high-pressure system that's sitting pretty nearly on top of us. As it moves off the coast, we'll come under a more southerly and then southwesterly and westerly flow as the system circulates clockwise around the center. That brings us warmer weather.

Overnight lows over the weekend, thankfully, will remain cool, in the 50s to near 60 degrees. So just open those windows for the night and shut the house up, and close the drapes during the day. You'll sleep better, and you shouldn't have to switch on the AC yet. Plenty of time for that as summer gets near.

Posted by Frank Roylance at 10:57 AM | | Comments (1)
Categories: Forecasts
        

Tremors rattle Pa. town north of Baltimore

USGSThe U.S. Geological Survey is reporting two small earth tremors this morning centered near Franklintown, Pa., between York and Carlisle, about 60 miles north northwest of Baltimore.

The first, rated at a magnitude 2.9, occurred at 1:36 a.m. The second, rated at 2.4, was recorded at 6:26 a.m. Both were shallow quakes - barely a mile below the surface. They were centered very close together. The first was a mile south of Franklintown, the second 2 miles east northeast of the town.

Earthquakes of this magnitude would not be felt by most people. But if you live in the area, and you felt something this morning, please leave us a comment and describe what it was like. Be sure to include your location, the time, and a description of the tremor.

Posted by Frank Roylance at 7:21 AM | | Comments (2)
Categories: Phenomena
        

April 23, 2009

Rains ends drought, but we're still "dry"

USDA/NOAA 

This morning's Drought Monitor map shows that recent rains have finally ended the drought conditions that had developed over the winter in as much as 80 percent of the state of Maryland. But while no part of the state is experiencing drought conditions this week, the entire state is still rated as "abnormally dry."

After extraordinarily dry conditions in February and March, BWI has recorded 5.71 inches of rain so far this month. The average April rainfall for Baltimore is 3 inches. We continue to run a paper deficit of almost 2 inches since Jan. 1. October, November and December also all saw rainfall deficits.

On the other hand, streamflow has improved, although levels are falling again in the wake of recent rains. Groundwater levels are improving, too, but some remain well below the averages for this time of year.

Concerns about whether we're really out of the woods apparently gave the Drought Monitor folks some pause. Here is a note I received today from one of the program's authors:

"As a USDM author and reader of your blog, I thought you might find it interesting to note there was a great deal of discussion with how to classify the situation in MD.  Recent rain (see attached) has been a boon for farmers, lawns, reservoirs, and general green up.  But there is an underlying concern over the near-record-low well water levels from March that were evident over much of MD:

http://md.water.usgs.gov/groundwater/web_wells/current/water_table/counties/

"It was the consensus that the path of least regret was to hold onto "D0" (abnormal dryness) with an "H" designator ("H" being hydrologic - or in this case, more specifically, ground water).  If well tables continue to climb, then it would not surprise me to see the D0 disappear altogether.  But there is some concern that we are still treading an slippery slope, and were not totally out of the woods yet.

"I just checked on the monitoring well up the street (from Jacksonville, where I live), and have a link to the info here...

http://waterdata.usgs.gov/md/nwis/uv?cb_72019=on&format=gif_stats&period=60&site_no=392045076512501

"Some items to note:

The current depth as of April 23 is 25.35'

The max depth (worst level) in this well's brief 7-year history was in 2002, 26.58'

The lowest depth (best level) was in 2004, @ 16.79'

"So we are a little more than a foot off the all-time (albeit brief sampling history) low, despite the recent rain. I do admit it's a bit of a hard sell (D0) on many, many fronts.  But it is hard to ignore the fact that as of yesterday, we are not seeing the type of rebound locally that I (being on well water) was hoping to see. - Eric

Eric Luebehusen

Meteorologist

USDA - World Agricultural Outlook Board

Posted by Frank Roylance at 12:59 PM | | Comments (2)
Categories: Drought
        

April 22, 2009

Sun weather station is back

The Sun weather station at Calvert & Centre streets is back on line after a week of unplanned down time due to a computer upgrade. There are some gaps in the data between April 16 and 22. But everything else appears to be up and running again.

The station feeds weather data every 10 minutes to Weather Underground. You can access it anytime and search its data base for downtown weather information back to the date it was established - way back in, well, January 2008. 

 

Posted by Frank Roylance at 3:45 PM | | Comments (0)
Categories: Notes to readers
        

Wettest April since 1983 recharges water table

The abundant rain that began falling on March 28 (the day The Sun ran my story on the state's deepening drought) is beginning to have an impact on groundwater supplies across the state, according to the U.S. Geological Survey.

USGS streamflow mapUSGS hydrologist Wendy McPherson reports today that water levels in monitoring wells and streams tracked by the agency are rising nicely. Many groundwater wells are now near normal levels for this time of year, and seem likely to continue rising.

That's the streamflow map at left. Dark blue indicates streams flowing at 90 percent of record levels for the date. Black indicates record flows. 

Wells that typically respond more slowly to rain events are behind the pace in their recovery, McPherson says. She cites a monitoring well in Baltimore County that has risen only a half-inch in the past week. It remains two feet below the level considered normal for this time of year.

"Fresh water is our most valuable resources because it is needed for all life on Earth to survive. The supply is not unlimited and we need to give water the respect it deserves and use it wisely, even when it is raining," she said.

April has so far produced 5.65 inches of rain at Baltimore-Washington International Thurgood Marshall Airport. That makes it the wettest April for Baltimore in 27 years, still short of the 6.55 inches that fell during the next-wettest April, in 1983. The long-term average for April is 3 inches, Baltimore's driest month.

Ten of the 15 wettest Aprils since 1871 occurred before 1950:

1889:  8.70 inches

1952:  8.15 inches

1937:  7.92 inches

1910:  7.76 inches

1933: 7.58 inches

1895:  7.42 inches

1940:  6.99 inches

1918:  6.79 inches

1929:  6.73 inches

1874:  6.65 inches

1983:  6.55 inches 

1973:  6.41 inches

1928:  6.26 inches

1924:  5.89 inches

2009*:  5.65 inches

* Through April 21

That said, the rain is expected to continue today and this evening in the form of scattered showers and perhaps a stray thunderstorm or two late today - much like last night's window-rattler.

We're also looking at a couple of cold nights as temperatures drop toward 40, and maybe into the 30s in some spots.

But the big picture is bright. These cold, rainy disturbances being dragged out of the northwest by the northern jet stream are on their way out with the jet itself. High pressure is on tap, with sunny skies Thursday and right through the weekend. As winds around the high shift to the south and southwest, daytime highs will start to rise, reaching the 60s on Thursday, the 70s on Friday and the 80s through the weekend and on into next week.

Break out the shorts!

Posted by Frank Roylance at 9:44 AM | | Comments (2)
Categories: Drought
        

April 21, 2009

Bad luck on Lyrid meteors, Venus occultation

Sun Photo/Karl Merton Ferron

Tomorrow morning could have been a triple jackpot for stargazers in Maryland - a nice, spring meteor shower, a rare close encounter of Venus and the crescent moon, and a nice flyby by the International Space Station - all in the hours before dawn. But, alas, bad luck in the form of clouds are conspiring to spoil the view.

The annual Lyrid meteor shower occurs as the Earth plows through the dusty trail of the comet Thatcher. As the sand-grain-sized bits of comet dust strike the atmosphere, they heat up the air around them and create fleeting trails of light across the sky.

NASAThe Lyrid meteors appear to emerge from the constellation Lyra, the lyre, because that's the direction toward which the Earth appears to be moving at this time of year. It's like snowflakes in the headlights. If the forecast were for clear skies, we could all gather in some dark place far from city lights, in the hours before dawn, and watch 10 to 20 meteors per hour - with higher rates possible if we got really lucky. 

But forecasters are calling for showers before 3 a.m., and mostly cloudy skies and a chance for more showers Wednesday morning.

The other attraction before the dawn on Wednesday was to be a close conjunction of the planet Venus and the waning crescent moon, low in the eastern sky around 5 a.m. For observers in the western U.S., the moon will actually pass in front of Venus, eclipsing its light for more than an hour. It's called an occultation. Here's a video of a recent one. For Marylanders, it is only a very close encounter, probably best observed with binoculars.

But given the forecast, the most practical equipment may be an umbrella. 

Finally, the International Space Station, appearing daily in the morning sky this week, will make a very bright pass just north and west of Baltimore on Wednesday morning. If skies were to clear in time, you could look for the ISS to appear above the western horizon at 5:32 a.m., rising like a bright, steady star to more than halfway up the northwestern sky by 5:35 a.m. before slipping off to the northeast and disappearing at 5:38 a.m.

All this information is for the optimists who may be willing to rise and shine and give it a go. For the rest, sleep tight.

Posted by Frank Roylance at 10:49 AM | | Comments (0)
Categories: Sky Watching
        

Thunderstorms possible today; 80s by the weekend

NOAA 

As the fog burns off and this morning's sunshine breaks through, it's tempting to expect a sunny day, all day. But forecasters out at Sterling say the solar heating and cold air aloft could set off some thunderstorms this afternoon and into this evening. Small hail and gusty winds could be part of the mix.

Showers - at least chances for showers- also remain in the forecast into Wednesday. But once these disturbances push through, we're set to break into some clear air and southwest winds that may push daytime highs into the 80s at BWI for the first time this year.

Curiously, there is mention of snow showers on the western slopes of the Alleghenies tomorrow and again Thursday morning.

The unsettled weather today and tomorrow is the result of a low-pressure system spinning over the Great Lakes, drawing cool air and precipitation south and east into our region as the atmosphere spins counter-clockwise around the low. As solar heating triggers convection from the surface, the warm air rises into the colder air aloft, setting off convection and the potential for thunderstorms.

The chances for precipitation are set at 40 percent today and 60 percent tonight, dropping to 30 percent tomorrow.

Today's thunderstorms could produce pea-sized hail, with penny-sized stones possible in some spots. The risk continues into the early evening. And, say the forecasters, "A few showers along favored slopes of the highlands overnight ... may mix with snow showers as colder air oozes into the [forecast area]."

Snow showers? What is this? Colorado? Actually, as the polar jet stream continues to dig deep into the Eastern U.S. there is a second mention of snow showers on the western slopes for Wednesday night into Thursday before the precipitation issues dry up for the weekend.

High pressure returns to the region Thursday, bringing mostly sunny skies through the weekend. The forecast high for BWI on Saturday is 82 degrees, with 80 degrees expected Sunday. The last time we saw 80 degrees at the airport was on Oct. 16.

Whatever your plans, remember your sun block and hats. And lets get some hats on those babies, people. There was an awful lot of bad-looking red skin in the locker room Monday morning. Saturday's high of 76 degrees drew a lot of pasty-looking people out into the sunshine. The instinct is understandable, but skin cancer is no joke. And we're just 60 days from the strongest sun of the year.

Posted by Frank Roylance at 9:59 AM | | Comments (0)
Categories: Forecasts
        

April 20, 2009

Did Yankees build a home run stadium?

AccuWeather.comThe flurry of home runs being smashed into right field at the new Yankee stadium has got meteorologists at AccuWeather.com wondering whether the geometry of the new ballpark may be enhancing the prevailing winds in ways that are blowing the balls over the wall.

Check out this story from AccuWeather.com


 

Posted by Frank Roylance at 1:49 PM | | Comments (2)
Categories: Observer reports
        

Forecast: See last week ...

This week is setting up to look a whole lot like last week as far as when we'll see rain and (eventually) sunshine. What you see out your window is what you get for the next couple of days, although the heavy rain and (possible) thunderstorms will give way to more showery events Tuesday and Wednesday.

Sun Photo/Frank RoylanceBut by Thursday, like last week, we will break into a warmer and drier pattern, with highs crowding 80 degrees by Saturday. The weekend, at least from this distance, looks much like this past weekend, which was terrific.

So far, here at Calvert & Centre streets, we have clocked in more than 0.6 inch of rain since it began around 7 a.m. Rain rates have topped 0.4 inch an hour at times. I'd link you to our station, but our data logger remains off line.

The airport has reported about the same amount. Add that to the total for April so far, and we're looking at just over 4.6 inches for the month to date. A "normal" April (the average for the 30-year period from 1971 to 2000) produces 3 inches of rain. Surprisingly, April is, on average, Baltimore's driest month. This time, it is the wettest month here since September 2008, which dropped 7.72 inches at BWI.

We could get as much as another three-quarters of an inch out of this storm before the low drifts off to the east. If thunderstorms develop as a warm front lifts through the region this afternoon, there is also the possibility of large hail and damaging winds, forecasters say. Keep a weather eye out between 3 and 9 p.m.

Then there's yet another low due in on Tuesday, with more showers along the associated cold front. Showers may linger into Wednesday before skies begin to clear out. 

In the meantime, we remain unseasonably cool, with highs today about 10 degrees below the long-term average for BWI at this time of year. By Friday, we'll be in sunshine again, and temperatures will rise well into the 70s, with weekend temperatures 5 to 10 degrees above the averages. Nice.

Posted by Frank Roylance at 10:50 AM | | Comments (0)
Categories: Forecasts
        

April 19, 2009

Ask, and ye shall receive

On today's print weather page, reader and frequent question-submitter Jeff Brauner asks why he hears the term "occluded front" so seldom these days:

"What is an 'occluded front'? Is that sort of an old-fashioned term that modern meteorologists don't use much anymore?" Occluded fronts occur when cold fronts sweep counterclockwise around a low-pressure center and overtake slower warm fronts on the other side, lifting the warmer air. Meteorologists do use it. Maybe they skip it in forecasts to avoid explaining it."

As luck would have it, there is a low-pressure system drifting our way today and, lo and behold, it has an occluded front extending southward from the center. It's the purple line in the weather map below. So as the showers arrive later today, you can amaze your friends by saying, "Hmmm, seems like rain associated with an occluded front."  And please report any instances of weather broadcasters actually using the term.

You ask. We provide. Your full-service weather blog.

NOAA/occluded front

Posted by Frank Roylance at 8:25 AM | | Comments (0)
Categories: Forecasts
        

April 16, 2009

Sun weather station is offline; a fix is coming

For the thousands of you who check downtown Baltimore weather conditions each month via The Sun's weather station at Calvert & Centre streets ... The regular (every 10 minutes) bursts of data from the station to the Weather Underground site, were cut off at 8:30 this morning.

The problem was an upgrade to the hardware on my computer, which also happened to remove the weather station software. The IT folks are busy doing similar upgrades on computers throughout the newsroom, so we're not sure when we can get the weather data moving again. But we're working on it. Honest.

 

Posted by Frank Roylance at 4:31 PM | | Comments (1)
Categories: Notes to readers
        

Space Station in full flower

NASA 

The most recent space shuttle mission to the International Space Station included the installation of the fourth and final pair of solar panels on the growing outpost. And that brought the station, finally, to the appearance that we have until now had to rely on NASA artists to provide.

So here it is (above). You can read more about it here. And here (below right) is how the place looked in September 2000.NASA

The ISS is, of course, visible from the ground with the naked eye in the early morning or the early evening after sunset, when the station is in sunlight and the observer on the ground is still in darkness. It's brighter than ever now with its new solar panels. Unfortunately, the next chance to see it from Maryland will be in the early morning hours next week - between 3:45 and 6 a.m. That's too early for my blood. But we will post the next good evening flyovers when they get closer.

Many amateur astronomers love the challenge of capturing recognizable images of the station through telescopes during these flyovers. Some are truly remarkable. Here's one that captured one of the spacewalking astronauts as he worked on the construction project during the recent mission. Amazing.  

Posted by Frank Roylance at 12:58 PM | | Comments (1)
Categories: Cool pictures
        

Is the drought over, already?

USDA/NOAA 

BWI airport has reported 4.11 inches of rain so far this month, the first monthly rain surplus since September, with more rain to come early next week. We're already 2.61 inches over the long-term averages for April to date in Baltimore. So surely the drought that began last month is over. Right?

Well, maybe. Or maybe not. This surplus has certainly reduced the moisture deficit we'd been building since October. Our garden dirt is wet, streams looked very high yesterday (although they are falling rapidly today), reservoirs surely got a boost (if they even needed one), and sagging water tables must be responding to these last three days of rain.

On the other hand, the Drought Monitor Map out this morning (above) shows no change in Maryland's status from last week's report. One hundred percent of the state remains at least "abnormally dry" on the map, and nearly 80 percent of that is still reported in "moderate drought" conditions.

But we need to take the Drought Monitor with a grain of salt. While the new map is reported on Thursday mornings, it reflects measurements that cut off at 7 a.m. on the previous Tuesday. This latest three-day rainfall began on Monday, so today's map misses most of the rain that fell on Tuesday, and all of yesterday's precipitation. So things may not be as dry as they look on the map. We only need to look outdoors to reach that conclusion.

So we may need to wait until next Thursday to get a truer reading on where we stand. And by then we will have received more rain, some of which will probably not show up on the next map for all the same reasons.

Whatever. The rain has certainly been good news. It's helped. A lot. And there's more on the way. That's all good.

As for the numbers, Pasadena wins the rainfall lottery for Wednesday, reporting more than 1.5 inches this morning for the last 24 hours. We had 1.17 inches here at The Sun. And out on the WeatherDeck in Cockeysville, my total for the three days came to 1.9 inches. Here are some measurements from across the state.

The forecast, meanwhile, remains terrific. Sunny skies into Sunday, with temperatures in the 60s to low 70s.

One caution: clear skies tonight will mean rapid radiational cooling. Some normally colder locations west of the metro areas could see some patchy frost tonight as temperatures sink into the 30s. If you already have tender plants growing outdoors, you know what to do.

Posted by Frank Roylance at 10:13 AM | | Comments (1)
Categories: Drought
        

April 15, 2009

Sunny and 72 degrees ... but not yet

Had enough rain and drizzle yet? Doesn't matter. We're in for another day of it today, although the menu should change to showers this afternoon and taper off overnight as this coastal low finally moves out to sea, and drier air slips in behind it.

The consolation prize will be a glorious weekend, with highs near 60 tomorrow rising to near 70 degrees for Friday and Saturday - all in sunshine. Springtime for Baltimore, at last.

Sun Photo/Frank RoylanceBut first, the rain. We've added another 0.64 inch in the last three days, on top of the 0.87 reported from BWI for Saturday. The month of April has seen almost 3 inches already, more than 1.5 inches ahead of the average pace for the month at its halfway mark.

Some locations have reported more, some less. Here are some 24-hour totals from across the state. 

Beyond the weekend, forecasters are looking at - more rain. A storm system now gathering itself together in the intermountain west is expected to spin this way by late Sunday or Monday. They're not sure how intense the system will turn out to be, but they're looking for more steady rain over two or three days.

Speaking of rain forecasts, researchers at the University of Washington have reported on surveys that suggest only half of us really understand what it means when forecasters say there is a 20 percent (or 50 percent, whatever the number) chance of precipitation.

An article in the Bulletin of the American Meteorological Society says many of the college students answering the survey believed, for example, that a 20 percent chance of rain means readers should expect rain over 20 percent of the forecast area, or for 20 percent of the time covered by the forecast.

What it actually means is that on 20 percent of the days with identical atmospheric conditions, there was rain. It's a probabilistic forecast, meaning there is also an 80 percent chance there will be no rain at all. Including that extra bit of information - the chance of no rain - greatly enhanced the students' understanding of the forecast, the study found.

And that understanding can have real economic consequences for people making decisions about such things as school closures, crop protection and snow clearing, the authors assert.

"A person who thinks that a probabilistic forecast means that a weather event will occur (in some percent of the area or for some percent of the time) may be more likely to take expensive precautionary action than someone who realizes that there is only a chance of that event occurring," according to a news release on the study.  

You can read the entire release by clicking the link below.

From the University of Washington:

If Mark Twain were alive today he might rephrase his frequently cited observation about everyone talking about the weather but not doing anything about it to say, “Everyone reads or watches weather forecasts, but many people don’t understand them.”

He’d do that because new research indicates that only about half the population knows what a forecast means when it predicts a 20 percent chance of rain, according to researchers at the University of Washington.

Writing in the Bulletin of the American Meteorological Society, the researchers said the confusion comes because people don’t understand what the 20 percent chance of rain actually refers to. Many people think it means that it will rain over 20 percent of the area covered by the forecast or for 20 percent of the time period covered by the forecast, said Susan Joslyn, a UW cognitive psychologist and senior lecturer.

“When a forecast says there is 20 percent chance of rain tomorrow it actually means it will rain on 20 percent of the days with exactly the same atmospheric conditions,” she said. “With the exception of the probability of precipitation, most weather forecasts report a single value such as the high temperature will be 53 degrees. This is deterministic because it implies that forecasters are sure the high temperature will be 53 degrees. But forecasting is probabilistic and 53 degrees is in the middle of the range of possible temperatures, say 49 to 56 degrees.”

To probe people’s understanding of the more familiar probability of precipitation, a technique used in public forecasts since the late 1960s, Joslyn and her colleagues tested more than 450 Pacific Northwest college students in three experiments.

The first experiment evaluated forecasts of either a low or a high percentage chance of precipitation accompanied by a series of icons, or “precipicons,” that were visual representations of the chance of rain. In addition to using a simplified cloud icon that is shown in many TV and newspaper forecasts, the researchers also used pie charts and bar graphs to indicate the chances of rain. Each student only saw one icon and forecast, and filled out a questionnaire.

Two of the questions asked how much of the time it would rain and over approximately what area of the region would it likely rain today. The correct answer for both questions was “can’t tell from this forecast,” and only 43 percent of the students correctly responded to both questions. Those who responded incorrectly were more likely to indicate they would wear a hooded jacket or carry an umbrella, actions suggesting they thought they were getting a deterministic forecast for rain.

The procedure was similar in the second experiment except the students were asked open-ended, rather than multiple-choice, questions, about similar weather forecasts. When asked to explain the probability of precipitation, few of the students did so and the percentage who correctly answered was close to the results of the first experiment.

The third experiment was similar to the first one. This time the participants received one of three forecasts. On one, the conventional chance of rain forecast appeared. On another, the chance of rain as well as the chance of no rain was given. On the third the pie chart icon appeared beneath the chance of rain.

This time 52 percent of the students knew that the forecast did not predict how much of the time and over what area it would rain. In addition, the odds of making an error were significantly lower if the phrase about a chance of no rain was included in the forecast.

Joslyn said the third experiment provides the first evidence that percent of time and area misconceptions can be weakened by an explicit statement that there is a chance it won’t rain.

She added that if the misunderstandings uncovered in this research exist among a college-educated group of students from the Pacific Northwest, where it frequently rains, then similar error probably occur in similar, or larger, numbers elsewhere among the general public.

The researchers believe that the errors are caused by the difficulty in making decisions when uncertainty is involved.

“In dealing with a forecast about rain people must simultaneously consider several hypothetical outcomes, their corresponding levels of uncertainty and their consequences. For some people it may be easier to commit to a single outcome, reducing cognitive load, and proceed as through the uncertainty has been resolved. In some cases they may not be aware of this simplification,” Joslyn said.

The research also has financial implications for forecast uncertainty and misinterpretations about such weather-related decisions as school closures, agricultural crop protection and highway and road clearing during storms. A person who thinks that a probabilistic forecast means that the weather event will occur (in some percent of the area or for some percent of the time) may be more likely to take expensive precautionary action than someone who realizes that there is only a chance of that event occurring.

The National Science Foundation funded the research. Co-authors of the study were Limor Nadav-Greenberg, a UW psychology doctoral graduate who is now in Israel, and Rebecca Nichols, a former UW undergraduate who is now a graduate student at the University of California, Irvine.

Posted by Frank Roylance at 10:36 AM | | Comments (1)
Categories: Forecasts
        

April 14, 2009

Wet, dreary and most welcome

NOAA 

Back in the saddle after a week off, during which I managed to catch a vacation cold, which I converted into an extra day off. But the good news is that despite the dreary skies - or rather because of them - we have returned to find a beneficially wet April underway. Writing about the drought two weeks ago seems to have helped. No charge.

The rain total for the month so far at Baltimore-Washington International Thurgood Marshall Airport stands at 2.76 inches. That's 1.44 inches wetter than the average April (through the 13th). Most of that rain has come from two very wet days - on the 3rd (1.55 inches) and on Saturday (0.87 inch). My new cherry tree seems quite happy.

Here are some daily totals from across the state. They've seen more than an inch in the last 24 hours in parts of Southern Maryland and the Eastern Shore, where they need the rain most. We've had more like a third- to a half-inch around Baltimore in the last 24 hours.

Keep your umbrallas handy. The forecast promises still more rain through Wednesday night - more than an inch of additional moisture - and maybe as much as two if we get lucky. That could make this the first month in Baltimore with a surplus of precipitation since last September. Depending on when you start counting, we are still working with as much as a 6-inch rainfall deficit. The total deficit since Jan. 1, 2009 is almost 4 inches. The slow, soaking nature of this precip helps even more than a heavy downburst would.

We can thank a low-pressure center just to our south and west. Its counter-clockwise spin is drawing cool, wet air in off the Atlantic Ocean. We'll get still more rain in the next 24 hours as the low moves off the coast and drags still more marine moisture our way, along with increasing winds into the late evening Wednesday.

It's all good, though. The rain we're getting this month should help Maryland's farmers get their planting done and get the seeds germinated properly. What's really needed now are some sustained surpluses to bring the water tables and streamflows back where they need to be to set up for summer.

All this and a good extended weekend forecast, too: Forecasters out at Sterling are predicting sunny skies from Thursday through Sunday, with highs in the 60s. Then another storm system could bring more rain by Sunday night into Monday.

Posted by Frank Roylance at 10:17 AM | | Comments (1)
Categories: Forecasts
        

April 6, 2009

Gone fishin'

Always figured April was the most beautiful month of the year, so the WeatherBlog will be off the air for a week while I re-acquaint myself with the planet in springtime, and with my favorite teacher. Against my better instincts, I will likely be back on the job by April 13.

In the meantime, you may talk amongst yourselves.

Sun Photo/Barbara Haddock Taylor 2008

Posted by Frank Roylance at 7:52 AM | | Comments (4)
Categories: Notes to readers
        

April 3, 2009

Hubble snaps galaxy triplets

 NASA/Space Telescope Science Institute

A while back NASA and the European Space Agency invited people to vote on which of a selection of never-before-imaged (by Hubble) celestial targets they'd like the Hubble Space Telescope to photograph. The voters chose something called Arp 274, a system of three galaxies in the constellation Virgo, 400 million light years from Earth.

The stunt was part of NASA's and ESA's celebration of the International Year of Astronomy, commemorating Galileo's early work with the telescope. Although he did not invent the telescope, as many people imagine, nor was he the first to aim it at the heavens, Galileo was the first to publish the findings of his telescopic stargazing, which had a profound effect on science and man's concept of his place in the universe. 

The Hubble photo was shot over the last two days, and it's now been published on the Web. It's a beauty. Enjoy.

Click here for more Hubble photos

Posted by Frank Roylance at 3:33 PM | | Comments (0)
Categories: Cool pictures
        

Drought affecting lower Susquehanna

The Susquehanna River Basin Commission has taken official note of the scarce rainfall and falling streamflow and water tables during the past three months in the lower part of the river's watershed, including northeast Maryland.

AP Photo/Chris GardnerThe commission has convened its interagency Drought  Coordination Committee in the face of the statistics, and called on residents in the region to start thinking about water conservation. The Susquehanna can become important to those of us on Baltimore City water, because when the city's reservoir system comes under pressure, its managers tap into the lower Susquehanna to augment supplies. If the river's water is low, water quality can decline, and our access can be restricted.

The commission warns:

"If below normal precipitation persists through spring, there could be water challenges that impact domestic water supplies, agriculture and other water-dependent businesses, aquatic habitat, recreation and other activities."

Click below for the full text of today's SRBC release.

HARRISBURG, Pa. – The Susquehanna River Basin Commission (SRBC) this week convened its interagency Drought Coordination Committee to assess growing impacts to water resources in the Susquehanna basin due to ongoing precipitation shortfalls.  Three consecutive months of shortfalls have caused streams and groundwater levels to drop well below normal for this time of the year, particularly in the Lower Susquehanna region in Pennsylvania and Maryland. 
The Drought Coordination Committee assesses five main parameters to determine emerging drought conditions: precipitation deficits, stream flows, groundwater levels, soil moisture and water-supply reservoir levels.  Precipitation deficits in the most impacted counties in Pennsylvania and Maryland range from 4 to 6 inches below normal for the past 90 days. 
“SRBC and other water management agencies are especially concerned about unseasonably low groundwater levels,” said SRBC Executive Director Paul Swartz.  “We are fast approaching the time of the year when groundwater recharge naturally ceases.  If we don’t get sufficient amounts of rain in the coming weeks, levels will continue to drop.  This means residents and businesses dependent on groundwater sources will have to rely on already-diminished supplies to get them through summer and late fall, when groundwater recharge normally picks up again.”
The interagency committee is coordinated by SRBC and includes representatives of water management agencies from the federal government and the states of Pennsylvania, Maryland and New York.  Committee members exchange technical information, assess current hydrologic conditions throughout the Susquehanna basin and offer management recommendations as appropriate.  
While NOAA’s National Weather Service is predicting slightly above normal rainfall in the early days of April, it will not be sufficient to address existing deficits.  Committee members will continue reassessing conditions and communicating over the coming weeks.  
If below normal precipitation persists through spring, there could be water challenges that impact domestic water supplies, agriculture and other water-dependent businesses, aquatic habitat, recreation and other activities. 
Given the current stresses on water resources in the lower Susquehanna region, SRBC is encouraging water conservation.  Water conservation tips for residential water users include:
-          Repairing leaking toilets (a leaking toilet can lose up to 200 gallons per day);
-          Repairing leaking and dripping facets (a leaking facet can lose up to 11 gallons per day);
-          Installing new shower heads and sink faucets equipped with water saving devices, such as aerators or spray taps;
-          Installing water saving appliances and devices, such as low-consumption toilets;
-          Taking short showers instead of baths;
-          Using dishwashers and washing machines only when filled to capacity;
-          Not letting the water run continuously while shaving, brushing teeth or washing dishes by hand;
-          Refrigerating tap water to avoid running the faucet waiting for the water to get cold;
-          Sweeping sidewalks and driveways, not hosing them down; and
-          Selecting more drought-tolerant vegetation and plant species for landscaping and using mulch to retain soil moisture.
Swartz said, “Without the return to a more normal precipitation pattern, we will undoubtedly experience water supply challenges and stresses on aquatic habitat later this year.  This makes water conservation that much more urgent.”
For more water conservation tips and other hydrologic information, go to SRBC’s Drought Center at: www.srbc.net/hydrologic/drought_center.htm.  This site also contains the Susquehanna River Basin Drought Coordination Plan that details: (1) the three drought stages and their purposes – watch, warning and emergency; (2) the proper procedures for monitoring droughts, issuing drought declarations and responding to drought conditions in the Susquehanna basin; and (3) the drought management activities of each member state and the U.S. Army Corps of Engineers.
SRBC (www.srbc.net) is the governing agency established under a 100-year compact signed on December 24, 1970, by the federal government and the states of New York, Pennsylvania and Maryland to protect and wisely manage the water resources of the Susquehanna River Basin.  The Susquehanna River starts in Cooperstown, N.Y., and flows 444 miles to the Chesapeake Bay at Havre de Grace, Md.

 

Posted by Frank Roylance at 12:17 PM | | Comments (0)
        

April showers ... finally

Sun Photo/Frank Roylance 

Now THAT's rain we can use. As I write, instruments here at Calvert & Centre streets downtown have clocked just over three-quarters of an inch since the rain began falling overnight. The airport has reported more than an inch. And it's still coming down pretty well - more than two inches an hour at times.

Creeks are rising, too. And here are some early rain totals from around the state.

The ride in to work this morning required switching the wipers to "fast." This would all seem to be more than the "showers" and maybe a quarter-inch total predicted by the National Weather Service for the day. Good for us. We need it. So does my new cherry tree.

All of this rain arrives out of the southwest ahead of a cold frontal passage, which could kick off some thunderstorms, gusty winds and hail along the I-95 corridor before it's over this afternoon. The weather service has posted a Hazardous Weather Outlook to that effect for the region.

The weekend still looks fine.

UPDATE: Rain total at The Sun, at 12:30 p.m. Friday:  1.25 inches. The airport: 1.41 inches.

Posted by Frank Roylance at 10:27 AM | | Comments (2)
Categories: Forecasts
        

April 2, 2009

Rain flops; next chance comes tonight

Yesterday at this time the forecasters out at Sterling were predicting rain showers were "likely" during the day Wednesday and into Thursday, with a tenth- to a quarter-inch in the cards for BWI. Well, a check of the rain gauge at the airport this morning finds a whopping 0.01 inch of water wetting the bottom.

NOAAThe forecast clearly flopped. The cold front slipped by with little more than a spritz and fog.

Here at Calvert & Centre streets, we did a little better, but not much. We picked up 0.04 inch overnight. The Eastern Shore did better, too, recording as much as a third of an inch.

Too bad. More than half the state remains in moderate drought this morning, with the rest rated "abnormally dry." No change from last week's drought map. The inch of rain we picked up along the way hasn't hurt, but it hasn't helped, either.

So today the prognosticators are calling again for showers after 1 a.m. tonight, but with less than a tenth of an inch expected. Showers and thunderstorms are forecast for Friday, with a tenth - to a quarter-inch due before the next cold front passes and skies clear for the weekend. Sunday night and Monday show more possibilities for showers and thunderstorms. But we'd best see it before we believe it.

Posted by Frank Roylance at 9:51 AM | | Comments (2)
Categories: Forecasts
        

April 1, 2009

Scientists baffled by sun's deep quiet

Where have all the sunspots gone? Solar scientists thought 2008 was the quietest year for solar activity on record. But 2009 has started out even quieter. The percentage of days without any sunspots visible on the sun's disk has increased this year to 87 percent, up from 73 percent in 2008.

NASAThis now ranks as the quietest ebb in the sun's 11-year cycle of rising and falling activity in almost a century. Among the notable effects so far:

* a 50-year low in solar wind pressure, which is allowing more galactic cosmic rays to penetrate the solar system, endangering space-walking astronauts. Lower solar wind pressure also produces fewer auroras.

* a striking slump in solar irradiance, or brightness. It's only 0.02 percent in visible wavelengths, but 6 percent in the ultraviolet. It's cooled and shrunk the upper atmosphere, extending the orbital lifetimes of satellites and junk in low-Earth orbit.

* a 55-year low in solar radio emissions. Nobody seems to understand this one.

You can read more about this odd solar minimum here.

Posted by Frank Roylance at 1:04 PM | | Comments (2)
Categories: Phenomena
        

Astronaut's head replaced with computer

NASA 

Frustrated by the quirks, flaws and general squooshiness of the human brain, NASA decided to replace an astronaut's head with a computer. It seems to work just fine, although it could use some additional miniaturization. That's astronaut Heidemarie Stefanyshyn-Piper performing a spacewalk with her new head during a mission last November.

Sorry. NASA started it. Happy April Fool's Day from the WeatherBlog.

Posted by Frank Roylance at 11:28 AM | | Comments (1)
Categories: Cool pictures
        

Winter's last gasp: Snow mix in western Md. forecast

Sun Photo/Amy Davis 2007 

It does take another breed to live in Western Maryland. It's cherry blossom time in the Chesapeake region, but forecasters are still dropping the S-word into their weekend forecast for the far western slopes of the Alleghenies. Is this a great state, or what?

But first, the immediate forecast for us lowlanders.

A look out the window this morning makes it clear that skies are darkening as clouds thicken up and rain approaches. There's a strong cold front draped along the Appalachians, from the Great Lakes to the Gulf, all trailing down from a deep low in Canada. As that front moves our way, the low is drawing warmer, moist air north off the Gulf and the Atlantic, and that spells a deepening cloud cover for us, and rain.

We are already getting some showers at Calvert & Centre this morning, although they have not shown up yet on our rain gauge. Forecasters say they could drop between a tenth- and a quarter-inch today, and a bit more this evening. The front should pass by late this afternoon, stalling well to our south. Look for fog in the morning.

Then the front reverses direction and returns as a warm front late Thursday, bringing another tenth- to a quarter-inch of rain before yet another cold front reaches us Thursday night into Friday morning, perhaps with some thunder.

Then skies begin to clear later on Friday as the front moves by us. But moisture in the air moving up the western slopes of the mountains could fall as a rain/snow mix before ending Saturday morning.

The weekend, at least, still looks great, with mostly sunny skies and highs in the 60s. Showers return late Sunday into Monday.

Posted by Frank Roylance at 10:40 AM | | Comments (0)
Categories: Winter weather
        
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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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