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March 31, 2008

April showers ahead

Back from vacation and feeling about like the weather looks outside these windows. Gloomy. I'd rather be on a sunny beach. Oh well. Looks like Wednesday may be our only sunny day this week. The rest is showers, drizzle, fog, and maybe a thunderstorm Tuesday night. That's April for you.

You can blame a high-pressure system over Boston. It's dragging cold, damp air in off the Atlantic. And once that's gone, we'll come under the influence of a storm system that will bring heavy rain to the Ohio Valley, Michigan and upstate New York. Points north of that will see heavy, wet snow. We get showers Thursday and Friday. The weekend - at least from this distance. looks nice - sunny, in the low 60s. That's if the forecast holds up, of course.

Despite some chilly days, March 2007 is winding up on the warm side. Temperatures averaged almost 45 degrees, a degree and a half above the long-term averages. Precipitation was low, just 2.34 inches, or an inch and a half below the norm. For the calendar year to date, we're 2.7 inches in the red. What rain we got in March was mostly skimpy showers. a few tenths, or hundredths of an inch here and there.

April in Baltimore sees average daily high temperatures rise from around 60 degrees to 69 by month's end. The average daily lows climb from 38 degrees to 47. But while the air warms up, and days grow longer, we're still at risk of a surprise snowstorm. We've had snow on Opening Day before, although that won't be an issue this year.

The biggest April snowstorm was on April 1, 1924, when 9.4 inches were recorded downtown. There are 12 other April dates with measurable snow on the record books - the latest on April 28, 1898. The most recent was just last year, on April 7, when 2 tenths of an inch fell at BWI.

The record high for an April day in Baltimore was 94 degrees, matched on four dates - in 1896, 1941 and 1960 (twice). The record low was 15 degrees, on April Fools Day, 1923.

But enough of such thoughts. Let's have some sunshine and balmy, fragrant April breezes. Pear blossoms, azalea riots, steak on the barby!

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

March 29, 2008

The space station and a bonus ... Maybe

Skies over Baltimore look a bit more promising tonight - at the end of a disappointing week for those who like to catch a glimpse of the International Space Station as it flies over Maryland with our money. ESA - Jules Verne ATVAnd this time, the sharp-eyed among us may get a bonus - a glimpse of the European Space Agency's Jules Verne automated transport vehicle - a cargo drone on a test run to the ISS this weekend. That's it at left. Here's more, with a video.

The forecast says partly cloudy. I guess we'll have to wait and see which part is cloudy, and whether we get enough of a break to spot the ISS. The station itself is plenty bright to be visible in hazy, twilight skies, but the Jules Verne is much smaller and therefore dimmer. And, it will be flying within about 10 miles of the ISS, so we may not be able to separate the pair except perhaps with binoculars.

Anyway, here are the specifics for tonight.

Watch for the ISS to rise above the western horizon at about 7:57 p.m. It will look like a bright star, except that it will be moving briskly toward the northeast. It will climb as high as 47 degrees above the northwestern horizon - that's about halfway between the horizon and the zenith (straight up) at 7:59 p.m. At that moment the station will be about 300 miles northwest of Baltimore.

From there is will zip off toward the northeast, passing above the W-shaped constellation Cassiopeia, and north of the Big Dipper. It will disappear from view at about 8:04 p.m. If you spot it, come back and leave us some comments.

Here's a link to more information about the Jules Verne. This will be our last shot at the ISS for a while. The forecast ahead looks rainy, and evening passes by the ISS will be very brief and low on the horizon, at least through April 7.

Posted by Frank Roylance at 3:34 PM | | Comments (1)
Categories: Sky Watching

March 28, 2008

Space Station flyover tonight, if skies clear 

No promises here. The forecast is still not very encouraging. But if we get lucky, the International Space Station should be visible over Baltimore just after 7:30 this evening.

Here's the scoop:  The ISS, with three astronauts on board, will be tracking northeast tonight, from North Florida to Cape Hatteras, and then out to sea. It may sound geeky, but lots of people have gotten a kick out of watching their tax dollars zip across the sky. Drag the kids away from their video games and get them to help you watch for the flyover. They're often the first to spot it. Young eyes.

As seen from Baltimore, the ISS will first appear above the southwest horizon at 7:34 p.m. Watch for what looks like a steady bright star, moving brisky toward the east. If it has multiple, or colored lights, it's an airplane. Keep looking.

It will reach it's highest point - about halfway between the southeast horizon and the zenith (straight up) at 7:37 p.m. From there, the station will track toward the northeast, appearing to pass very close to the planet Saturn and the bright star Regulus, which are side-by-side above the eastern horizon at that hour. The ISS will then disappear on the southeast at about 7:40 p.m.

Regular satellite watchers say the ISS has become very much brighter since astronauts have added new modules, solar panels and radiators. It can be the brightest object in the night sky.

After watching the flyover, come back here and leave us a comment, and share the experience with those who missed it. If this one is clouded out, we'll have a better shot tomorrow night. Stay tuned.

Remember, you can calculate ISS predictions for your own location at

Posted by Frank Roylance at 7:47 AM | | Comments (3)
Categories: Sky Watching

March 25, 2008

Space station views this week washed out

And here I thought I'd have a nice series of bright flyovers by the International Space Station to enjoy during my vacation. Alas, the arrival of a cold front tonight - and forecasts that it will stall over the region with clouds and showers for the rest of the week - have washed out those plans.

The astronauts aboard the ISS will be flying over a solid deck of clouds. And we'll be beneath it. We might even have caught a glimpse of the shuttle Endeavour, which has undocked from the ISS in preparation for the ride home.

Had the forecast been for clear skies over the next few nights, we could have enjoyed nightly, early-evening flyovers. Instead we get this

That's the cold front - the blue line draped along the Ohio Valley on this weather map. It extends from a low now over eastern Canada. Once it gets here, it will hang around way too long. There's no sunshine predicted again until Sunday.

Our temperatures will depend on which side of the front we find ourselves on. Could be in the 60s. Or, not.  The forecast discussion suggests there is a "potential for a huge bust in temperature forecast given usual uncertainties with exact position of front..."

Bummer. I'm takin' a nap.

Posted by Frank Roylance at 2:20 PM | | Comments (1)
Categories: Sky Watching

March 20, 2008

Gone fishin'

Spring is in the air. The peepers are singing down by the creek and blossoms are busting out all over. It's time the old Weather Blogger took some time to get out and enjoy it, instead of sitting in here writing about it.

I may pop up during the next week to post a notice about a space station flyover (there are some nice evening passes coming up), or some other event I can't resist. But mostly I will be spending time with my favorite teacher, and watching Sam Zell on You Tube. 

Happy Spring!

Posted by Frank Roylance at 5:37 PM | | Comments (2)
Categories: Notes to readers

March winds put a chill on

Just back from a reporting trip to the Maryland Zoo, where Felix has finally given birth to her new calf. Standing out in the wind with the zoo folks and the elephants, we all felt colder than we have all winter. That cold wind out of the west and northwest cuts right through you, and the bright sunshine does little to compensate for the wind chill.

Winds here at The Sun have been gusting as high as 29 mph this morning. With temperatures around 50 degrees, the wind chills are running a bit less than 40 degrees. Out at BWI, they've clocked sustained winds in the 20s, with gusts as high as 39 mph this afternoon. 

There are gale warnings on the Bay, where data bouys at noon were reporting winds and gusts over 30 knots.

Wind advisories have been posted across most of Maryland, advising of gusts as high as 45 mph through 10 p.m. today.

AccuWeather.comIt will get colder tonight, with lows just below freezing. Friday, the next low-pressure system will start to approach from the northwest (left), bringing us a renewed chance for precipitation on Friday night. Garrett Countians may see a few more inches of snow, and even the northern tier of Maryland counties could see some flakes mixing in as we catch the clipper's last gasps.

Longer range, forecasters are watching the computer models as they wrestle with the track of a potential snowstorm expected to visit the East Coast next week. One model has the storm taking a more westward track and visiting snow upon the mid-Atlantic and New England states. But the rest keep the storm to our south, and along the coast, sparing the urban corridor. Here's's Henry Margusity on the topic. Even he seems to be doubtful about this one.

Posted by Frank Roylance at 1:38 PM | | Comments (1)
Categories: Forecasts

March 19, 2008

A half-inch of rain already; more to come

The rain gauge here at Calvert & Centre streets has already clocked in nearly a half-inch of rain at this writing. BWI has seen nearly as much. This is just the start of a rainy, and possibly stormy night tonight ahead of a cold front.

The same weather system has caused heavy rains, flooding and 10 deaths in the Midwest. Some spots have recorded 10 inches of rain or more. Here's more on that, plus some video.

We won't likely see anything close to that.  But forecasters out at Sterling are calling for up to another half-inch tonight before the front goes by, winds shift, and cooler, drier air pushes in from the west. Here's the radar loop.

Here's why we're so socked in:




Posted by Frank Roylance at 5:48 PM | | Comments (0)
Categories: Events

Wind, rain, high water in Annapolis ahead


Strong winds out of the south later today are piling up water in the northern end of the Chesapeake Bay. That, coupled with lunar tides (the moon will be full on Friday) will produce unusually high tides this evening along the Western Shore. Gale warnings will go up at 2 p.m. on Maryland's portion of the Bay.

The graph above shows tides are already running well above predicted levels at Baltimore.

The National Weather Service has issued a Coastal Flood Advisory through 6 a.m. Thursday,  alerting coastal interests to high tides as much as two feet above predicted levels, with minor flooding possible in the usual vulnerable spots, including City Dock in Annapolis and Old Town Alexandria in Virginia. We could see the water lapping over the bulkhead at the water taxi dock at Harborplace, too.

Here's the advisory, with high tide times along the Western Shore.

And as a cold front approaches from the west tonight, we can expect showers, and maybe a thunderstorm and damaging winds - perhaps even an isolated tornado - until the front goes by. The severe weather, if it materializes, would reach us sometime between 11 p.m. and 3 a.m., forecasters said.

Once the front passes, winds will shift to the west or northwest. That will drop temperatures sharply, and take the pressure off the Bay, returning tides to more normal levels. Here's the forecast.

Posted by Frank Roylance at 10:58 AM | | Comments (0)
Categories: Forecasts

March 18, 2008

A windy day in Texas

I have no idea what this TV news interview today was all about. CNN does not provide any context. But we can say one thing for sure: it was taped on one heckuva windy day in Texas. Have a look.

I wonder who the roofing contractor was on that job. Yikes!

Posted by Frank Roylance at 5:09 PM | | Comments (0)
Categories: Cool pictures

March 17, 2008

Big Asian export to U.S.: air pollution

Measurements of air pollutants over the North Pacific have documented one of Asia's biggest exports - air pollution. A NASA study has concluded that some 40 billion pounds of aerosols - smoke, ash, and acid droplets from forest fires, coal stoves, automotive and industrial exhaust  - drifted out across the Pacific between 2002 and 2005. About 10 billion pounds of that reached North America.

That incoming pollution is about 15 percent the volume of the pollution we generate ourselves. The study's lead author, Hongbin Yu, of the University of Maryland Baltimore County, said, “This is a significant percentage at a time when the U.S. is trying to decrease pollution emissions to boost overall air quality. This means that any reduction in our emissions may be offset by the pollution aerosols coming from East Asia and other regions.” Yu is an assistant research scientist at UMBC, currently working at the NASA Goddard Space Flight Center in Greenbelt.

Satellites have tracked the pollution during its journey from East Asia and Russia, and provided scientists with data for their estimates of the volume and contents of the brown clouds. Rapid industrial growth in China has made matters worse, the study found.

Here's how it looked to the satellite's instruments on one day in 2003. You can read all about it here.


Posted by Frank Roylance at 6:14 PM | | Comments (0)
Categories: Air quality

Atlanta tornado video

There are some amazing online videos of the Atlanta tornado. Here is a sampler:

Here's one from CNN: 

Here's some local TV footage, from an airport webcam:

More local TV video, from a helicopter:

A walking tour of downtown Atlanta:

Here's video of the hailstorm as the tornado approached: 

Another walking tour, with MalaniKai:





Posted by Frank Roylance at 12:23 PM | | Comments (0)
Categories: Tornadoes

Rain/snow mix back in the forecast

Really. You'd never guess it with the bulbs popping up, tree blossoms ready to burst, and highs in the 60s forecast for mid-week. But this is springtime, and the cold air to the north and warming sunshine to the south are clashing, and we'll feel them both this week.

First, we can enjoy the sunshine today as highs edge into the 50s. Things will cloud up tonight, though, as the high pressure moves off the coast and we get into the return flow from the south. The southerly flow will bring us a chance for showers tomorrow. Forecasters say some areas up near the Pennsylvania border could still be cold enough to see snow mixing in with the showers early tomorrow.

Things will stay mild Tuesday night as an approaching warm front brings more light showers and gusty winds. The south winds could produce some minor flooding along the bay shore.

All this is prelude to what forecasters expect will be a sharp cold front late Wednesday. They're comparing it to the front that blew through with heavy rain and wind on Mar. 4-5, dropping temperatures 10 degrees and roughing things up in Carroll County.

Maryland's western mountains could see some snow showers in the wake of the front late Wednesday, followed by clearing skies and gusty winds. Thursday and Friday look sunny and seasonable. 

The forecast for late in the week includes hints from the computer models of a storm off the Pacific Ocean that will cross the continent and bring us showers by the weekend, with temperatures cold enough to mix some snow into the brew. There's also talk of a Gulf storm figuring into the weekend forecast. But it's way too early to know how all this will evolve for us.

Whether you see flakes this week or not, the snow is not far away. Here's the snow and ice cover across the continent, as of Sunday, from the National Ice Center:

National Ice Center



Posted by Frank Roylance at 11:26 AM | | Comments (0)
Categories: Forecasts

March 14, 2008

March showers bring ... more March showers

This morning's sunshine will fade as the day wears on. We're stuck beneath a boundary between cool marine air to the north, and warmer air to the south. This line becomes a pathway for a series of disturbances that forecasters say will bring us a few isolated showers this afternoon, and more showers tonight, mostly in the northern counties and Western Maryland.

"A rumble of thunder cannot be ruled out," forecasters said in this morning's discussion from Sterling. On the other hand, it will be a mild day, with a high in the low 60s.

This initial patch of showery weather will fade as the system moves off to the east early Saturday. Saturday will start drier, but another, stronger batch of rain will move in to replace it late in the day, increasing the chances for more showers Saturday night into Sunday morning.

Once THAT bunch of rain moves off, more high pressure will move in behind another cold front. We'll see cooler, more seasonable temperatures later on Sunday, with more sunshine, highs in the 50s and breezy conditions. That will make for a sunny day on Monday, too, before the next weather-maker brings in more showers on Tuesday or Wednesday.

So pack an umbrella and smile.  Spring (almost) showers are a good thing.

Posted by Frank Roylance at 10:51 AM | | Comments (0)
Categories: Forecasts

March 13, 2008

Last week's rain helped; drought persists

 Drought Monitor

BWI picked up almost an inch and a half of rain last week. Other parts of the state saw even more, and the impact can be seen on this week's Drought Monitor map. It's out this morning, and reflects soil moisture, rain, and streamflow as of this past Tuesday.

The numbers show significant improvement, but extreme southern Maryland and the Lower Eastern Shore remain in some drought distress.

Rain reduced the "severe" drought zone in parts of Worcester and Wicomico counties. The percentage of the state experiencing severe drought slipped from 11.5 percent to 9.6 percent.

Conditions in the Baltimore area also improved. The northern tier of counties from Garrett, through Carroll, Baltimore, Harford and Cecil are once again enjoying normal moisture conditions, an increase from 31 percent of the state on last week's map, to 49 percent today. The gains allowed Baltimore City last week to shut off the flow of supplementary water from the Susquehanna River.

"Moderate" drought conditions, which prevailed last week from the Chesapeake Bay Bridge southward to St. Mary's County and Hooper's Island on the Eastern Shore, is limited now to extreme Southern Maryland and Dorchester County on the Shore.

Overall, just 51 percent of the state is still contending with "abnormally dry" or drought conditions, down from almost 69 percent last week.

On well water? Groundwater conditions are slowly improving, too. Here's a fresh look at the water table in a USGS monitoring well in Granite, Baltimore County. The record low on this well is 28.2 feet, reached in 2002. The median for this time of year is between 22 and 23 feet below the surface. It's currently at 25 feet and change. Still low, but climbing.


Meanwhile,'s long-range forecaster Joe Bastardi is predicting the La Nina-related dry weather we've seen since last April will continue. Here's what he said in a release issued today:

"While precipitation this winter was not as far below normal as during the fall and summer in the Southeast, the La Nina pattern still suggests the drier-than-normal trend will continue, probably into at least the summer," said Bastardi. "Combining this with the general trend of drought produced by the warm phase of the Atlantic Ocean water temperature cycle, much of the Southeast will remain in dire straits for the longer term."

"As a warning to farmers and gardeners, Bastardi added that dry weather may combine with occasional cold air charging into the Southeast from Canada to produce a late frost threat in the Southeast, perhaps into mid-April."

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

March 12, 2008

Mild, showery, boring


Not much weather news to write about this morning, at least not around here. Forecasters are looking for seasonable-to-mild temperatures as the week unfolds. The long-term average high temperatures for Baltimore in mid-March are in the mid-50s. And that's what we'll see for the next week or so.

The photo above was shot from orbit yesterday. It shows plenty of overcast over Maryland, and lots of snow on the ground in upstate New York and New England.

The air will dry out over Baltimore later today, and provide some more sunshine, a high around 55 degrees. We should get some nice stargazing in after 10 p.m. tonight, with a low around freezing under the clear skies. Temperatures will rise into the high 50s Thursday, and even into the mid-60s on Friday as we fall into the return, southerly flow from the fair weather system as it moves out to sea. But after another cold front moves past on Friday the temperatures will drop back toward the norms.

Look for showers on Friday into Saturday along with the next frontal passage. But we can still use the moisture, so we'll take it. The rest of the week - from Sunday well into next week - we'll see plenty of sunshine. 

Like I said. Boring. Nothing like the weekend's amazing roller coaster. You saw the Sunday rainbow photo we posted yesterday. Wind gusts on Saturday reached near-hurricane force in some places, with a high of 73 mph in Westminster. Here are some wind gust figures from the National Weather Service.

Posted by Frank Roylance at 11:02 AM | | Comments (0)
Categories: Forecasts

March 11, 2008

Dangerous water on the Potomac

Great Falls of the Potomac - National Park Service

Runoff from heavy rain and snow melt are not a problem just on the Susquehanna this week. The Maryland Natural Resources Police have issued an advisory, warning against most recreational uses of the Upper Potomac River, through Friday.

Based on data from the National Weather Service and the Maryland Emergency Management Agency, the DNR said hazardous river levels persist this week on the Upper Potomac all the way from Cumberland, in Allegany County, to Little Falls, in Montgomery County. Here's a look at data from Point of Rocks.

Wading fishermen, swimmers (in March!?) and anyone venturing onto the river in non-whitewater boats or tubes runs a risk of life-threatening hypothermia, wave action, high-velocity or treacherous currents, the DNR police said.

These hazardous conditions exist along the Potomac itself, as well as on adjacent rivers and creeks.

The advisory does not apply to "professionally guided river trips," or "teams of experienced whitewater paddlers," the police said. All the same, be careful out there. We don't need to be writing any search and rescue stories.

For river condition updates, call 703 260-0305.

Here's another shot of the Potomac as it can be when the water is high and fast. It was shot at Mather Gorge by Emmy Truckenmiller. No date is provided. Used here with permission from American Whitewater.

Mather Gorge - Emmy Truckenmiller 

Posted by Frank Roylance at 3:52 PM | | Comments (0)
Categories: Events

Rainbow spectacle over Baltimore

Back doing the NEW journalism this morning after a day doing the OLD journalism and chasing the Goob down in College Park. Got back to Calvert Street and had a chat with Kurt Kocher, the spokesman for the city's Department of Public Works, about the easing drought conditions.

Kurt sent me this terrific photo he shot of a rainbow that appeared over Baltimore during Sunday's wild weather transitions. The location is Belair Road, near the county line.

Kurt Kocher

 The rainbow appeared as a cold front swept across Maryland. A broad gap in the cloud cover allowed sunshine to beam through the departing rain showers, producing the rainbow. Then another bank of clouds and showers moved in.

Here's what the gap in the clouds looked like from space.


In the meantime, rain and snowmelt to our north was sending huge volumes of water down the Susquehanna River. Operators of the Conowingo Dam were forced to open the floodgates to let the water pass. Frances Bowman, of Perryville, took the opportunity to drive up to the dam and shoot some pictures. Here's one she sent us. Wow.

Frances Bowman

The Susquehanna remains high, and flow rates through the dam continue well above - looks like five times - the norms for this time of year. Here's the chart:


Posted by Frank Roylance at 10:08 AM | | Comments (2)
Categories: Cool pictures

March 7, 2008

Susquehanna crests, more rain due

The Susquehanna River, swollen by recent rains and melting snow in Pennsylvania and New York, appears to have crested at the Conowingo Dam, with only minor flooding overnight in Port Deposit. Flood warnings for Harford County have been dropped, but a watch continues in Cecil County, largely because of heavy rains expected late today and tomorrow. 

Folks along the river remain on watch. Flooding continues in Marietta, Pa., about 35 miles upstream from Conowingo, but the water is receding. The water levels remain high, but discharge from the dam had slowed by this morning to less than 300,000 cubic feet per second. It is also well below the record daily discharge for this date - March 7 - of 462,000 cf/s in 1979. Here's the discharge graph:


As a pair of potent storms approach the region this afternoon, we all can expect heavy rain through the night and into tomorrow. 

The barometer at BWI and here at The Sun has already begun to sink sharply ahead of the approaching storms. Forecasters at Sterling say we can expect as much as an inch and a half of rain before it's over late on Saturday. Then the sun comes out for most of next week, with seasonable highs in the 50s.

The problems this weekend come to us thanks to a low developing over Alabama this morning. That one will get here tonight. "In a nutshell, it's going to rain," said NWS forecaster Andy Woodcock in this morning's discussion.

Here's the radar loop. The heaviest rain will hit tonight as the low moves into Virginia. As much as an inch could fall, with the potential to bring the Potomac River to flood stage above Harper's Ferry by Saturday morning.

After a lull, the rain will pick up again later on Saturday as another storm center moves in with a cold front. We'll get more heavy rain and then gusty winds behind the front, continuing into Sunday, even as skies clear off.

Looking ahead, Woodcock says, there's a chance we'll see a "strangely similar" procession of rainstorms exactly a week from now, developing along the Gulf and zipping up the East Coast with a peck of rain for the mid-Atlantic. And that's a good thing so long as your basement stays dry.

Posted by Frank Roylance at 10:19 AM | | Comments (1)
Categories: Flooding

March 6, 2008

Pack an umbrella Friday

No, we can't complain about it. Almost half the state remains in a moderate to severe drought. But we need to be aware that there's more rain ahead tomorrow and Saturday as another strong late-winter storm spins up the Appalachians and threatens heavy snow to our north and west, and significant rain for us.

Forecasters out at Sterling are calling for rain beginning after 3 p.m. Friday, continuing through the night and into Saturday morning. Total accumulations - rain - could exceed an inch and a half before it's all over. Forecasters are considering a flood watch for the I-95 corridor, but there may not be quite enough rain in the system to warrant that. Here's's take.

And once the cold front behind the bad weather passes, temperatures will drop from the 50s on Saturday, into the 20s Saturday night. Out on the ridges to our west, they may see a few flakes mixed into the precip before it's over.

If you're still looking for snow, this would have been a good snow-maker for us had the storm tracked farther south, or the temperatures been colder to begin with. But alas, you will have to travel to Ohio, Pennsylvania, upstate New York or Ontario to get in on the snow action.

From Sunday through Thursday at least, we can look forward to mostly sunny weather and seasonable temperatures. But never lose hope. My colleague Jacques Kelly still thinks we'll see a decent snowstorm before we're done. The Capital Weather Gang is recalling March of 1960, which capped a similarly snow-starved winter with a good, last blast in March. Here's more on that.

Posted by Frank Roylance at 3:46 PM | | Comments (2)
Categories: Forecasts

Record runoff discharging at Conowingo Dam

Flood warnings remain in effect in Harford and Cecil counties today as record rain and snowmelt in Pennsylvania and New York send high water down the Susquehanna River. The river has already passed flood stage at Marietta, Pa., about 35 miles upstream from Conowingo. It appears to have crested at Harrisburg.

UPDATED: The water below the Exelon Power Corp.'s Conowingo Hydroelectric Station is forecast to reach 25.5 feet by this evening, then begin to fall. At 10:30 a.m. it was at 24.5 feet. That is a foot above flood stage (23.5 feet). Minor flooding is occurring, according to the National Weather Service; "moderate" flooding is expected.

The forecast, if realized, would bring the river to Notification Level 5, with 21 to 25 of the dam's 53 gates open. At Level 5, backyards and basements on Main Street, and Tome's landing in Port Deposit begin to flood.

An earlier NWS forecast had predicted the river level would reach Level 6. An earlier version of this post indicated that level had already been reached. It has not. Your weather blogger regrets the error. Here's more on the Notification levels..

The webcam photo was taken in June 2006, during runoff from heavy rains. If anyone snaps some pictures there today, send them along and we'll post them.

Webcam photo of Conowingo in June 2006Water was rushing through the dam this morning at a rate of 323,000 cubic feet per second. The previous record for a March 6 was 320,000 cf/s in 1979. The average for this date is 70,500 cubic feet per second. The all-time record high flow was 1.13 million cubic feet per second, on June 24, 1972, in the aftermath of Tropical Storm Agnes.

Below is a graph of the discharge rate at 9:30 this morning. You can get real-time data on the discharge by clicking here.







Posted by Frank Roylance at 10:24 AM | | Comments (4)
Categories: Watches and warnings

March 5, 2008

Spring peepers are, well, peeping

Pseudacris crucifer  

Okay, as far as I'm concerned, it's spring. As I walked from my car to my front door last night, I heard the first spring peepers calling from the soggy flood plain of Western Run in Cockeysville.

These tiny frogs are a sure sign that winter is on the run, and froggy love is in the air. It also tells me that the wetlands along the river remain healthy enough for the frogs, turtles, fish, deer and occasional beaver I've seen down there. It's a miracle, frankly, with all the development in Hunt Valley, with more to come. The Brightview folks are planning a new assisted living facility on the rise above the peepers' love nest. Baltimore County zoning hearings on the proposal are coming up.

In the meantime, if you haven't heard the peepers, or just love their jingle-bell calls, here's a Web site that offers a sound file. It's very cool.


Posted by Frank Roylance at 11:55 AM | | Comments (2)
Categories: Events

Storms topple trees, wires, structures

Sun photo by Kim Hairston

Utility crews work to repair wind damage at Ritchie Highway and Wellham Avenue this morning. Sun photo by Kim Hairston.

Last night's storms knocked down a surprising number of trees, utility poles and wires across the region overnight as they heralded the passage of a new cold front and the end to our balmy weather. They also collapsed a barn roof and a garage in Frederick County. Here's a summary of damage reports.

The damage also caused some traffic disruptions this morning.

Heavy downpours produced some minor flooding west of the urban centers. Flood Warnings are posted from Frederick County west to Allegany County. Parts of the Potomac River, the Monocacy and the Conococheague were expected to crest above flood stage in the next few days. Here's the full list of Flood Warnings.

The rain left 0.4 inch in the gauge at BWI, and 0.45 here at Calvert & Centre streets. Winds at the paper gusted as high as 30 mph overnight, and 35 mph out at the airport. As much as 2 inches fell in other parts of the state. Here's a rainfall map. Here are some other readings across the region.

The forecast offers two good days now that the cold front has moved off into the Atlantic. High pressure returns , and today and tomorrow should be sunny and mild for this time of year - in the 50s, with overnight lows above freezing.

Then a new storm center moves in to our west, and another tracks up the coast, delivering more showers on Friday into Saturday. Once that's past we get somewhat cooler temperatures Saturday and Sunday - 40s daytime and 20s at night. Sunday's your best bet for outdoor activities this weekend.

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

March 4, 2008

A hard rain's gonna fall

 NWS radar

Does your basement get wet in heavy rain? If so, you may not like this forecast. We should get through most of the day today with little more than some showers. But rain will likely intensify tonight as a cold front approaches from the west. Flood watches remain in effect for all of Maryland west of the Chesapeake Bay.

Forecasters out in Sterling are giving us a 30 percent chance of showers today as south winds continue to keep us in moist, mild air. The overnight temperatures at BWI dropped to 48 degrees just after midnight, but turned around and climbed for the rest of the night as more mild southern air piled in, reaching 58 degrees after daybreak. We could approach 70 today in places away from the colder waters of the bay.

Tonight, as the cold front approaches, the rainfall will intensify. The forecast gives us a 100 percent chance of precipitation, and they're calling it "heavy rain," lingering into the morning tomorrow. As much as three-quarters of an inch are possible, with winds gusting to 26 mph.

Forecasters, however, do seem to be hedging a bit. This morning's discussion from Sterling notes that there is very little snowpack in Maryland to worsen the flood risk - and none at all in the urban centers. And it appears the heaviest rain may fall with thunderstorms, which forecasters think will track mostly south and east of I-95. There's some notion that the flood watch might even be cancelled later today, as the storm system evolves.

In the meantime, we can watch the satellite imagery and the radar loops as this pretty impressive system develops, drawing a strong train of moisture out of the Gulf, and dragging a very sharply defined front across the eastern part of the country. If this thing moves quickly enough, whatever heavy weather we get shouldn't last too long.

Then we get a bit of a break late Wednesday into Thursday before the next rain and cold front push through Thursday night into Friday. Stay tuned.

Posted by Frank Roylance at 8:33 AM | | Comments (1)
Categories: Forecasts

March 3, 2008

A touch of spring, then rain

Sunshine, plus temperatures well into the 60s today and tomorrow will make it seem like spring has arrived. But with spring-like weather comes the inevitable clash of warm air from the south and lingering cold from the north. Severe weather building in the South today will move our way Tuesday, bringing plenty of rain and even a chance of a thunderstorm Tuesday night. 

Severe weather is forecast today from East Texas east into Tennessee. We will likely be reading shortly of wind damage, heavy downpours and perhaps some tornadoes to our south and west. Here's the forecast for Jackson, Miss.

We remain on the back side of the high-pressure system that has kept us in sunshine for several days. The clockwise circulation around the high is drawing warm, moist air our way from the south and west. That will push our temperatures to 65 or so this afternoon, and a few degrees warmer than that tomorrow. The records are safe, but it will seem very spring-like - about 15 degrees above the seasonal norms.

By tomorrow afternoon, the severe weather will be crossing Alabama and Georgia and rain will spread into the Ohio Valley and the mid-Atlantic states ahead of a cold front.

The threat of heavy rain, on top of a rapidly melting snow cover in Maryland's western mountain counties, has prompted the National Weather Service to post a Flood Watch for Garrett County. They could see 1.5 to 2 inches of rain out there in Maryland's Lake Country, beginning late Monday night and continuing into Tuesday.

UPATE: The Flood Watch has been extended across all of central Maryland, from Tuesday afternoon through Wednesday morning. Here's more.

Earlier: We have no snow to melt here, of course, but we will see enough rain to run the risk of some flooding in low urban settings and poor drainage areas, forecasters say. They're talking about an inch or so down here.

Behind the cold front, we can expect, well, cooler temperatures for the rest of the week. The sunshine returns after some morning showers on Wednesday, with highs near 50 degrees, which is the norm for this time of year at BWI. And that's pretty much the story for the rest of the work week - seasonable temperatures, with partly to mostly cloudy skies.


Posted by Frank Roylance at 10:20 AM | | Comments (2)
Categories: Forecasts
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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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