With onshore winds predicted at the approach of Saturday's storm, and plenty of moisture expected to run up onto the eastern slope of the Appalachians, the National Weather service has begun hoisting flood watches for the region.

The southeast winds will push high tides two to three feet above tide table predictions along the western shore of the Chesapeake, and the tidal Potomac River. Those tables already accounted for the approach of the full moon on Sunday.

The moisture picked up by the storm from the Gulf of Mexico and the Atlantic will be squeezed out of the air as it is forced up the eastern slopes, with more than an inch of rain expected. That will raise the risk of flash flooding, as the rain falls on ground already wet, if not saturated, by recent rains.

So, the NWS has posted a Coastal Flood Watch for the Western Shore counties (blue on the map) on Saturday and Saturday evening, including all of Southern Maryland, plus Anne Arundel, Baltimore and Harford counties. 

Here are the times of Saturday's high tides:

HAVRE DE GRACE...9:11 PM...
BOWLEY BAR...6:49 PM...
FORT MCHENRY BALTIMORE...5:58 PM...
ANNAPOLIS U.S. NAVAL ACADEMY...4:28 PM AND 4:58 AM...
CHESAPEAKE BEACH...3:11 PM AND 3:41 AM...
SOLOMONS ISLAND...1:50 AM...
POINT LOOKOUT...1:00 AM...

NOW ALONG THE POTOMAC RIVER...
WASHINGTON CHANNEL...7:27 PM...
ALEXANDRIA...7:45 PM...
INDIAN HEAD...7:13 PM...
COLTONS POINT...2:29 AM...

The Flash Flood Watches are posted for Allegany County and counties (green on the map) in western Virginia and the eastern portions of West Virginia. 

"A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT COULD
LEAD TO FLASH FLOODING. MONITOR THE LATEST FORECASTS AND BE
PREPARED TO TAKE ACTION SHOULD FLASH FLOOD WARNINGS BE ISSUED."

Posted by Frank Roylance at 11:15 AM | Permalink | Comments (0)
Categories: Watches and warnings
        

FROM TODAY'S PRINT EDITIONS:

Steve Connor, in Parkville, asks: “What is the biggest difference between the high and low temperature … on the same day?” Steve Zubrick, at the NWS, found the biggest change on a single calendar date was 48 degrees, on April 1, 1978, from 40 degrees to 88. The biggest 5-day drop in Baltimore was 62 degrees - from 87 degrees on Oct. 20, 1969 to 25 degrees on the 24^th. The widest 5-day rise was 68 degrees, most recently on March 4-8, 2009 - from 8 degrees to 76 degrees.

Posted by Frank Roylance at 12:01 AM | Permalink | Comments (0)
Categories: From the Sun's print edition, Sky Notes
        

Here's the rainfall prediction from NOAA's Hydrometeorological Prediction Center in Camp Springs. It shows most of the heaviest rain due on Saturday will fall to the west of Baltimore and Washington. Many locations will see more than an inch, with some in line for 1.5 inches or more, especially in thunderstorms. (Click to enlarge.)

Posted by Frank Roylance at 3:38 PM | Permalink | Comments (0)
Categories: Forecasts
        

Observers from the National Weather Service's regional forecast office in Sterling, Va. say minor wind damage April 5 in eastern Prince George's County and western Anne Arundel County southeast of Crofton was caused by a "brief, weak" tornado.

The twister, which was moving at nearly 60 mph, was rated an EF-0 on the Enhanced Fujita Scale. It was part of a fast-moving line of line of thunderstorms that also produced an EF-0 tornado and minor damage in northern Charles County, near Waldorf, minutes later.

Meteorologists said the Arundel tornado struck at 4:55 a.m. Its path was about 50 yards wide with a length of 1.3 miles, with top winds estimated at 60 mph. It produced "minor" tree damage in the communities of Sherwood Manor and Patuxent Preserve.

The ground survey team reported that several pine and hardwood trees were blown over in Sherwood Manor, and several pines were topped 15 feet above the ground south of Patuxent Preserve. No structural damage was seen.

Posted by Frank Roylance at 10:31 AM | Permalink | Comments (2)
Categories: Tornadoes
        

FROM TODAY'S PRINT EDITIONS:

As forbidding as the North Atlantic can be, 2,224 people aboard the RMS Titanic 99 year ago this week are thought to have had pretty nice weather for their first three days at sea, with light winds and mild temperatures. They made good time. But on the 14^th, they ran into a cold front moving off Canada. The mercury fell from the 40s to near freezing. Northwest winds drove an ice field into the ship’s path. The water temperature was 28 degrees early on the 15^th, when 1,513 people were lost.

(SUN PHOTO: Jed Kirschbaum, 2005)

Posted by Frank Roylance at 12:01 AM | Permalink | Comments (1)
Categories: From the Sun's print edition, Sky Notes
        

This slow-drip water torture should be thinning out this afternoon, giving way slowly to some clearing skies this evening. The best news is that Sterling is forecasting sunny skies for Thursday, with highs in the upper 60s. Even Friday will bring some sunshine, but with cooler temperatures as winds swing to the east and bring in more moisture and clouds.

The wind shift will signal the approach of the next low, and the likelihood of some heavy rain and thunderstorms on Saturday. The storm comes to us from the Midwest, but the counter-clockwise circulation around it will draw wind and gobs of moisture off the Gulf and the Atlantic.

It will also be a slow-mover, providing more time for the rain totals to pile up. The NWS forecast allows for as much as 1 to 2 inches before it all ends on Sunday. The period of heaviest rainfall will be Saturday, lingering into Saturday night and possibly Sunday morning.

The NWS has issued a Hazardous Weather Outlook statement, noting the risk of heavy rain Saturday and the possibility of flash flooding as already-high streamflow rates are swelled by even more runoff. 

Skies will start to clear later in the day Sunday, becoming partly sunny, with highs around 60 degrees.  Monday looks nice, with the next chance of rain on Tuesday.

Keep the umbrella handy. Here's Prof. Jeff Halverson's take on the weekend storm. He's an associate professor of Geography and Environmental Systems at UMBC:

"If there is any good news for Saturday's soaking rainstorm, the models today have backed off the amplitude of the cutoff low they were projecting yesterday...in fact, the cutoff appears that it will shear out and de-amplify as it crosses the Mid Atlantic. 

"So while the intensity of the upper level dynamics may diminish somewhat, the cold temps in the remnants of that disturbance aloft will keep the atmosphere unstable...and combined with Atlantic low-level moisture...a widespread rainy day, w/ possible periods of moderately-heavy rain, are still reasonably assured." - Jeff Halverson, UMBC

Posted by Frank Roylance at 12:13 PM | Permalink | Comments (1)
Categories: Forecasts
        

FROM TODAY'S PRINT EDITIONS:

Like baseball, weather is a game of statistics. Averages, extremes, records and trends are all of interest to the aficionado.

And here’s one I’d never noticed: In Baltimore, April 13 to 18 is, on average, one of the two driest periods of the year. On those dates, the average daily rainfall (since the 1870s) has been just 0.09 inch.

Except for a similar period in the fall (Oct. 23-26), average daily rainfall ranges from 0.10 to 0.14 inch. The wettest days are in mid-September. Who knew?  

(SUN PHOTO: John Makely, April 2006)   

Posted by Frank Roylance at 12:01 AM | Permalink | Comments (1)
Categories: From the Sun's print edition, Sky Notes
        

Showers today, tonight and Wednesday could drop more than an inch of rain in some locations across Central Maryland. But forecasters are looking ahead to what could be some heavy rains late Friday into Saturday.

Once the low-pressure system darkening our skies today and Wednesday moves east and away from the mid-Atlantic coast, our skies will clear as high pressure moves in. Temperatures have been falling all night, and won't get much higher today than they are this morning. By tomorrow we'll be looking at highs again in the 50s. Sunshine returns Thursday, but the blue sky will be short-lived.

By Friday night, the high pressure will be moving off, and the next storm system will be cranking up over the Midwest. As that low intensifies, it will draw what forecasters are calling "copious amounts of Atlantic/Gulf of Mexico moisture" into our region. Sterling says it's still too soon to say precisely where the rain will be heaviest, or how much will fall. But you can plan on your Saturday being wet.

Sunday, at least, looks partly sunny and cool, with a high in the 50s.

Jeff Halverson, associate professor of georgraphy and environmental systems at UMBC, says the storm is a classic "cut-off" low.

"A cut-off is a large, cold, upper-level cyclonic vortex that has broken free from the westerly jet stream ...It's a bit of a rogue whirlpool, and it moves sluggishly, and can even become stationary overhead," he said. This particular cutoff will gain strength from a powerful surface low over the Great Lakes, and another low expected to develop over the mid-Atlantic.

"Because of the cold air aloft (an unstable atmosphere) and a good tap on Atlantic/Gulf of Mexico moisture in a southerly flow ahead of the front, heavy periods of showers w/embedded thunder are a good bet Saturday-Saturday night-Sunday AM." 

(SUN PHOTO: Frank Roylance, April 11, 2011)

Posted by Frank Roylance at 8:21 AM | Permalink | Comments (1)
Categories: Forecasts
        

FROM TODAY'S PRINT EDITIONS:

March in Baltimore was warmer and wetter than average, in step with the averages for the contiguous 48 states, according to NOAA. BWI averaged 44.3 degrees (slightly warmer than the norm), with 4.99 inches of rain, third-wettest March since 2000. But averages can deceive. The Pacific Northwest saw one of the wettest Marches on record, while Texas saw its driest. The area in “severe” and “extreme” drought doubled to more than 20 percent of the Lower 48 states. (Click on Drought Monitor map to enlarge.) 

Posted by Frank Roylance at 12:01 AM | Permalink | Comments (0)
Categories: From the Sun's print edition, Sky Notes
        

Instruments at BWI-Marshall Airport this afternoon show the temperature at 4 p.m. had reached 85 degrees. That ties the record high for the date, set 124 years ago, in 1887.

The temperature at The Sun's weather station at Calvert and Centre streets was 86 degrees. It was 73 closer to the bay in Annapolis, and 75 degrees at Martin State Airport in Middle River.

It is the second Monday in a row that the mercury has reached a record high in the 80s at BWI. For the Orioles' home opener April 4, the high was 86 degrees at 5 p.m. That broke the old record of 83 degrees, which had stood since 1956. The average high for an April 11 in Baltimore is 63 degrees.

Temperatures this time began to drop after clouds thickened ahead of tonight 's rain. It was 84 at 5 p.m. Forecasters said the 4 p.m. reading was likely to be the day's high at BWI.

Records at Washington's Reagan National Airport and Dulles International seemed safe this afternoon. It was 82 at Reagan at 4 p.m., where the record set in 1930 for the date is 91. At Dulles, the 4 p.m. reading was 84, and the record set in 1977 is 87 degrees. 

The heat won't last.

"The high tomorrow [Tuesday] will only be ... 62 for Baltimore," said NWS meteorologist Heather Sheffield, from the regional forecast office in Sterling, Va. "The cold front moves through and the rain will continue into tomorrow."

"We have a kind of a low forming as the front goes through, and that will keep the showers around tomorrow," she said. "It looks like by late tomorrow [Tuesday] night the low will be moving off the coast."

That should bring the sun back sometime Wednesday or Thursday, forecasters said. More showers and thunderstorms are forecast for late Friday and Saturday. Daytime highs drop back to the 50s early next week.

(SUN PHOTO: Frank Roylance, 4/11/11)

Posted by Frank Roylance at 4:03 PM | Permalink | Comments (0)
Categories: By the numbers, Sky Notes
        

FROM TODAY'S PRINT EDITIONS:

Baltimore, you’ve made it. Today is the average last frost date for the city. It’s an average; we could still get, well, frosted. But it’s the first of the average last-frost dates for Maryland as warmer weather invades the state. Annapolis follows on the 23^rd, according to NOAA via the Victory Seed Co., then Cambridge on the 26^th, Hagerstown on May 3 and Pocomoke on May 8. Gardeners in chilly Oakland, out in Garrett County, bide their time until June 5.

(SUN PHOTO: Frost on grass. Kim Hairston, 2005)

Posted by Frank Roylance at 12:01 AM | Permalink | Comments (0)
Categories: From the Sun's print edition, Sky Notes
        

With a warm front moving north overnight, and warmer, wetter air pushing into the region from the south, forecasters say we can expect "another very warm Monday." 

The forecast high is 82 degrees for BWI-Marshall Airport. That's just 3 degrees below the record high for the date - 85 degrees, set in 1887. Dulles Airport in Northern Virginia is looking for a high of 84 degrees, which could threaten the record of 87 set for the date there in 1977.

Last Monday's forecast called for a high of 78 degrees. But the NWS folks out at Sterling, Va. regularly underestimate the warm-weather highs at BWI. So we guessed we would top that and threaten the record of 83 degrees for an April 4 in Baltimore. We did. The day's high at BWI was a record-breaking 86 degrees. It was 87 downtown for the Orioles' home opener.

So we may well threaten the April 11 record of 85.

The setup is the same. Forecasters say the wedge of cold air that has kept us cool all weekend will be moving north overnight as a warm front. Southwesterly winds and increasing moisture will mean temperatures may turn and head higher well before dawn. That will raise dewpoints, bringing us some morning fog. Once that burns off and skies clear, the April sunshine will heat us up even more.

And, just like last week, there is a cold front expected to cross Central Maryland Monday evening behind the warm front. That will raise the risk of showers and thunderstorms, probably after midnight Monday night, with as much as a half-inch of rain. There's "slight" risk some of those storms will be severe in northeastern Maryland, capable of damaging gusts and large hail.

The same scenario last week brought a small tornado to northern Charles County and brief, but powerful wind gusts to parts of Southern Maryland.

Behind the front, forecasters say we can expect more seasonable temperatures again, with highs in the 60s and lows in the 40s for the balance of the week. Mid-week looks sunny, with rain chances returning Friday night into Saturday.

Posted by Frank Roylance at 9:26 PM | Permalink | Comments (0)
Categories: Forecasts
        

FROM TODAY'S PRINT EDITIONS:

April 10-12, 1894 were miserable days for Marylanders. It was cold; the high in Baltimore on the 10^th was 40, still a record-low high for the date. A coastal storm with 60 mph winds battered ships. Two coastal schooners went aground in New Jersey, drowning 20 seamen. Two days of sleet and snow piled up 5 inches of slush in the city. The Sun reported: “The barn and wagon shed of Samuel Crocker, Chestnut Ridge … collapsed. Several hogs were killed by the falling timber.”  

(SUN PHOTO: Kenneth K. Lam, April 7, 2003)

Posted by Frank Roylance at 12:01 AM | Permalink | Comments (0)
Categories: History
        

FROM TODAY'S PRINT EDITIONS:

Lots of people were awakened before dawn Tuesday by roaring winds as a sharp squall line and thunderstorms crossed the state. But only little Marbella, in northern Charles County, can claim a tornado.

The National Weather Service looked at the damage and declared it was a minimal EF-0 twister that snapped ornamental trees and toppled a big pine onto a house. It carved a path 50 yards wide, and raked the ground for just a tenth of a mile. The whole event lasted less than a minute.

(SUN PHOTO: Doug Kapustin, 2005)

Posted by Frank Roylance at 12:01 AM | Permalink | Comments (0)
Categories: From the Sun's print edition, Sky Notes
        

FROM TODAY'S PRINT EDITIONS:

The PJM Interconnection, which manages the electric grid across all or part of 13 states, including Maryland, has issued its 2010 annual report. Last summer’s heat drove electric demand above 100,000 megawatts on more than 70 days, a new record. Consumers in the mid-Atlantic were asked to curtail demand on three dates. After adjusting for the heat, summer demand still grew by 1 percent over 2009, the largest such increase since 2006, attributed to a recovering economy.

(SUN PHOTO: Karl Merton Ferron, July 2010)

Posted by Frank Roylance at 12:01 AM | Permalink | Comments (0)
Categories: By the numbers
        

The violent wind storm that blew through parts of Charles and Calvert counties before dawn on Tuesday produced what the National Weather Service has described as a "brief, weak tornado." It was rated an EF-0 on the Enhanced Fujita Scale.

The twister generated winds as high as 65 mph, according to the NWS report. It struck at about 4:48 a.m. in the community of Marbella, near Waldorf in northern Charles County, and lasted less than a minute. Damage included a large pine blown over onto a house, several ornamental trees snapped, and damage to a fence.

The path of the funnel cloud, produced by a fast-moving line of thunderstorms, was about 50 yards wide but only a tenth of a mile long, according to investigators from the NWS regional forecast office in Sterling, Va. No injuries were reported.

Posted by Frank Roylance at 1:06 PM | Permalink | Comments (0)
Categories: Tornadoes
        

Okay, so we were too gloomy yesterday. The NWS forecast called for "mostly cloudy" skies Wednesday and a high of 61, and we went with it. The day turned out to be a beautiful spring offering, with clear skies into the early evening, and a high of 65 in downtown Baltimore. Perfect.

So today they're calling for "mostly cloudy" skies again, and a high of 65. And it looks beautiful out there around the State Penitentiary, which is all I can see from the newsroom window. So let's just call it a happy break from the cold and wet weather we've seen most days since the equinox, because the weekend - while there's a warmup coming - also looks pretty wet.

Forecasters out at Sterling have posted a seven-day forecast listing rain chances, unequivocal rain, likely rain and risks of showers for pretty nearly every day and night through Monday. Highs will sag back into the 50s Friday before climbing back to forecast maxima of 71 on Sunday and "near 80" on Monday.

The problem is a weak cold front that's forecast to stall near the Mason-Dixon Line. It's colder north of the front, and warmer south of the front. Washington should see highs in the 70s today. Light rain is possible late tonight, with more likely Friday as disturbances move along the stalled front, and again Saturday.

Things warm up considerably Sunday and Monday as the line moves north again as a warm front. The next cold front will be close behind on Monday, with thunderstorms possible as it passes by, trailing behind a low crossing the Great Lakes. Despite the name, temperatures are forecast to remain mild after the cold front goes past, with highs Tuesday and Wednesday predicted to reach the low 70s, under mostly sunny skies.

Speaking of mild spring weather, have you noticed the pollen counts for trees? They've reached "high" levels in the region this week. But then, if you have allergies, you didn't need anyone to tell you that. Come to think of it, my throat's been kind of scratchy... You?

Posted by Frank Roylance at 10:37 AM | Permalink | Comments (3)
Categories: Forecasts
        

FROM TODAY'S PRINT EDITIONS:

Just as spring gets rolling in Earth’s northern hemisphere, the northern half of Mars tonight marks the beginning of winter. The Martian winter solstice occurs at 11 p.m. EDT tonight.

Joe Rao, writing in Guy Ottewell’s Astronomical Calendar, notes that Mars’ north polar axis tilts 25 degrees from the sun in winter, similar to Earth’s 23 degrees. But Mars takes two Earth years, and 50 days to circle the sun. So the northern winter on Mars will drag on ‘til Sept. 13.  Pity the poor Martians.  

(NASA PHOTO: Polar ice on Mars)

Posted by Frank Roylance at 12:01 AM | Permalink | Comments (0)
Categories: From the Sun's print edition, Sky Notes
        

A week after AccuWeather.com posted its spring prognostications for the 2011 Atlantic hurricane season, it's Colorado State University's turn. The mountain folks who never experience a hurricane are once again predicting an "above-average" storm season.

That's due in large measure to the fact that we are in a multi-decadal cycle that began in 1995 during which we should expect storm totals above the long-term (1950-2000) average in most years. The 16-year period between 1979 and 1994 saw 25 major (Cat. 3, 4 or 5) hurricanes. The 16 years since have witnessed 61. 

The CSU scientists expect the cycle to continue for another 10 to 15 years before switching back to a long, less active phase.

The CSU forecast is also very close to the one issued by AccuWeather.com a week ago, except for a slightly more aggressive prediction on the number of "major" storms - Cat. 3 and above. Here's how the two predictions out so far compare:

AccuWeather.com, March 30: Named storms: 15. Hurricanes: 8. Major: 3

Colorado State, April 6: Named storms:  16. Hurricanes: 9. Major: 5

1950-2000 average: Named storms: 9.6. Hurricanes: 5.9.  Major: 2.3

The new CSU forecast includes a reduction, by one named storm, in the numbers released in the school's December forecast. 

The CSU team led by Phil Klotzbach, of the CSU Tropical Meteorology Project, points to several factors contributing to their calculations. "We expect that anomalously warm tropical Atlantic sea surface temperatures, combined with neutral tropical Pacific sea surface temperatures will contribute to an active season," he said.

The tropical Pacific is important because El Nino (above-average sea surface temperatures in the eastern and central tropical Pacific) tends to suppress hurricane development in the Atlantic, while La Nina or neutral temperature conditions tend to allow storm development. After a La Nina winter in 2010-2011, the sea surface temperatures in the Pacific have been warming up and are expected to be neutral this summer. 

The Colorado team also looks at oceanic and atmospheric conditions in the Altantic and makes comparisons with those that existed during the summer in 29 prior years. They consider how those storm seasons turned out and then develop their "best estimate" of how the next season will look.

The closest analogs for the 2011 setup were found to be 1955, 1996, 2006 and 2008. All except 2006 had neutral or La Nina conditions, and all but 2006 were "very active" seasons.

Just where this year's storms can be expected to make landfall is impossible to predict with any precision. But the coastal regions of the United States have been extraordinarily lucky in recent years, said longtime hurricane forecaster William Gray, the other key member of the CSU team.

"Except for the very destructive hurricane seasons of 2004-2005, United States coastal residents have experienced no other major landfalling hurricanes since 1999. This recent 9 of 11-year period without any major landfall events should not be expected to continue," he said.

The team predicts a 72 percent chance that at least one major hurricane will make landfall in the U.S. The long-term average probability is 52 percent. The landfall chances for the East Coast, from Florida north, is put at 48 percent. The long-term average probability is 31 percent.

Last year in April, the CSU team predicted 15 named storms, 8 hurricanes and 4 major hurricanes. The actual count was 19 named storms (the third-most active season on record), 12 hurricanes, and 5 major hurricanes. No hurricanes made landfall in the U.S. 

Posted by Frank Roylance at 12:42 PM | Permalink | Comments (2)
Categories: Hurricanes
        

Pretty crisp out there this morning. Temperatures at BWI-Marshall Airport dropped to 34 degrees overnight, down 52 degrees from Monday's record high of 86. Had to scrape some ice and switch the car heat back on.

The bright April sunshine is nice, but sadly it's going to fade as the day wears on. Look for high clouds to move in as the clear, high pressure moves east and a weak disturbance to our north drags a cold front this way. The northern counties could see a few drops of rain, but mostly we'll get just clouds with highs in the 60s Wednesday and Thursday.

UPDATE, 6 p.m.: Clearly, the cloud cover headed our way has been delayed, due now to arrive overnight. So we snuck in a fine day in spite of the earlier forecast. We deserved it. But the clouds are close. Earlier post resumes:

The clouds will keep overnight lows from dropping below the 40s, so we shouldn't have to scrape windshields again. The cold front (click map to enlarge) is forecast to dip south Thursday, bringing us rain chances Thursday night, increasing to 70 percent by Friday. Those of us who wind up north of the front will get a steadier rain, forecasters said. Those to the south will see a more scattered variety, with a chance for thunderstorms, and milder temperatures.

Groundskeepers at Camden Yards will be watching the skies as they try to squeeze in the Rangers' games.

Rain chances diminish to 30 percent for Saturday and rebound to 40 percent Saturday night. But they don't relent until Sunday. Forecasters predict "mostly cloudy" skies Sunday, with a high near 63 degrees. That looks like the outdoor day this weekend.

Still looking for a break in the weather? Hang on a while longer. Forecasters say disturbances moving along the stalled temperature boundary will mean a persistent 40 percent chance of showers through Monday. Schedule your mental health day for Tuesday which, at least from this distance, looks to be sunny, with a high of 72 degrees.

Posted by Frank Roylance at 10:12 AM | Permalink | Comments (2)
Categories: Forecasts
        

FROM TODAY'S PRINT EDITIONS:

Opening Day at Camden Yards was a sunny, deliriously hopeful day for O’s fans. It was made even more delightful by crazy-warm weather for early April, with a downtown high of 87.

But our cool, drippy spring resumed on Tuesday. In fact, BWI has had a trace of rain (or more) for seven straight days now, including the early morning of Opening Day.

March saw the first monthly precipitation surplus since September, with 4.99 inches, more than an inch above the norm.   

And temperatures at BWI have averaged below the norm for 11 of the last 14 days.

(SUN PHOTO: Karl Merton Ferron, April 2004)

Posted by Frank Roylance at 12:01 AM | Permalink | Comments (0)
Categories: From the Sun's print edition
        

With temperatures forecast to dip to between 31 and 36 degrees early Wednesday, the National Weather Service forecast office in Mt. Holly, N.J. has issued a Frost Advisory for agricultural interests on the Eastern Shore.

The advisory covers Talbot, Caroline, Kent and Queen Anne's counties, and the southern two-thirds of Delaware (blue on the map). The highest risk will come between 3 and 6 a.m. At risk are early blossoms and "tender vegetation," forecasters said.

Of course, far Western Maryland is still dealing with snow today, but they're not really into their growing season out there as the Eastern Shore is, so no advisories have been posted west of the bay. (Check out this highway cam for Keyser's Ridge.)

All the same, the overnight low tonight for Baltimore and its suburbs is expected to sink to the low 30s. So if you do happen to have anything "tender" outside, you'll probably want to cover it or bring it indoors.

A drop from 86 degrees at BWI on Monday afternoon to a low of 43 degrees early this afternoon is a fall of 43 degrees. By Wednesday morning we may have dropped a total of 53 degrees or more in 36 hours. Pretty impressive.

Posted by Frank Roylance at 4:29 PM | Permalink | Comments (1)
Categories: Watches and warnings
        

Meteorologists from the National Weather Service's regional forecast office in Sterling, Va. were en route to Southern Maryland this morning to investigate storm damage reports for evidence of a possible tornado.

Sterling's Kevin Witt said the office had received reports of downed trees and structural damage in the area. "We're sending people out to areas that seem like they were the hardest-hit," he said. No final determination is expected before late today or Wednesday morning.

The NWS issued a Tornado Watch for portions of Baltimore City and County at 2:18 a.m. Tuesday, effective through 10 a.m. But that watch was canceled at about 5:45 a.m. after the threat had passed.

There was also a Tornado Warning issued at 4:55 a.m. for northern, eastern and central portions of Anne Arundel County. But the damage reports this morning were limited to Southern Maryland, in Charles and Calvert counties.

Posted by Frank Roylance at 12:06 PM | Permalink | Comments (0)
Categories: Tornadoes
        

Suburban counties around Baltimore and Washington recorded as much as a half-inch of rain from the showers and thunderstorms that rolled through overnight. But apart from the rain, and some winds gusting to 39 mph at BWI, there was little else to show for the ruckus. A Tornado Watch issued just after 2 a.m. was later canceled.

BGE reported only a few hundred outages overnight. Temperatures, which reached a record 86 degrees Monday at BWI-Marshall Airport, dropped back into the 50s by daybreak as the cold front moved through, and we aren't expected to see the 70s again until next week.

The only storm damage being reported by the weather service this morning are some downed poles and wires near Port Tobacco, in Charles County, and similar tree damage in Calvert County. Rain and snow showers were in the forecast this morning for parts of Garrett and Allegany counties.

The photo is from Sunday night's storm, in Howard County. Here are some rain totals for last night from across the region, as reported by the CoCoRaHS Network:

Sykesville, Howard County:  0.52 inch

White Oak, Montgomery County:  0.51 inch

Baldwin, Baltimore County:  0.47 inch

Columbia, Howard County:  0.46 inch

Reisterstown, Baltimore County:  0.38 inch

Bel Air, Harford County:  0.35 inch

Baltimore City:  0.34 inch

Severn, Anne Arundel County:  0.21 inch

(PHOTO: James Willinghan, Howard County, 11:15 p.m. Sunday, April 3, 2011. Used with permission)

Posted by Frank Roylance at 8:21 AM | Permalink | Comments (5)
Categories: Storm reports
        

FROM TODAY'S PRINT EDITIONS:

What was it about the April weather in Baltimore in 1874 and 1875? Official record-keeping here had only begun a few years earlier, in 1871. But in those two years alone we established nine weather records that have not been broken in the 135 Aprils since. Mostly it was the cold – record lows (in the 20s and 30s) on five dates, and record-low daily highs (in the 30s and 40s) on three dates. The string of records was capped on April 29, 1875 with a 2.5-inch rainstorm.  

(SUN PHOTO: Kennth K. Lam, April 7, 2007)

Posted by Frank Roylance at 12:01 AM | Permalink | Comments (0)
Categories: From the Sun's print edition
        

UPDATE, 5 p.m.: The mercury at BWI-Marshall Airport touched 86 degrees at 5 p.m. Monday, establishing a new record high for the date. The previous record for an April 4 in Baltimore was 83 degrees. It had stood for 55 years, since 1956.

This is the second time this year the thermometer has topped 80 degrees at the airport. The first was on March 18, with a high of 81, also a record for the date.

The 1956 record of 83 degrees was the lowest daily record high for April. The lowest record high now is 84 degrees, set on April 5, last year. 

Washington's Reagan National Airport reported a high of 85 degrees, tying the record set there in 1956. Dulles International reported 84 degrees, breaking the 81-degree mark set on this date in 1999. 

This is the warmest weather Baltimoreans have seen since an 91-degree reading on Sept. 25, 2010. Perfect weather for Opening Day.

The graph above is for The Sun's weather station, not BWI. We reached 85.6 degrees at 4:50 p.m., after a climb from 46.9 degrees at 5:20 a.m., a gain of 38.7 degrees. 

By the way, the NWS is predicting rain and snow showers behind the cold front early Tuesday morning for the high ridges of the Maryland mountains. Really.

Here are some other 5 p.m. readings from around the region:

Maryland Science Center, Baltimore: 87.1 degrees

Andrews AFB:  84.7 degrees

Patuxent River NAS: 84 degrees

Dulles International Airport:  84 degrees

Reagan National Airport:  84 degrees

Frederick:  82.0 degrees

Hagerstown:  80.1 degrees

Annapolis:  75 degrees

Martin State Airport:  73 degrees

Petersburg, Va., reported a reading of 90 degrees shortly after 5 p.m.

Posted by Frank Roylance at 4:04 PM | Permalink | Comments (0)
Categories: By the numbers
        

There are no official severe storm watches or warnings posted yet for Central Maryland. But BGE has assessed the forecast and put its crews on alert for the power outages that thunderstorms and gusty winds could bring to the region tonight. In a news release this afternoon, the utility said:

"An approaching cold front could bring one to two inches of rain tomorrow morning, along with wind gusts of close to 50 miles per hour. These weather conditions could cause trees and tree limbs to come down onto power lines and other electric delivery equipment, interrupting service to customers.

"BGE has canceled non-emergency maintenance work and is in the process of identifying available resources, including BGE linemen and contract tree crews to ensure service can be restore to customers as safely and as quickly as possible."

The National Weather Service has posted a Hazardous Weather Outlook for most of the state west of the bay. It says:

"THUNDERSTORMS WILL BE POSSIBLE AFTER MIDNIGHT. THESE WILL BE
CAPABLE OF PRODUCING DAMAGING WIND GUSTS AND HEAVY RAIN THAT COULD
LEAD TO FLASH FLOODING."

Temperature at The Sun at 2:50 p.m.:  81 degrees

Temperature at BWI at 3 p.m.:  82 degrees. Record high for the date is 83. I'm guessing this heat will pop those tree buds, get the grass growing and send pollen counts climbing. Welcome to the allergy season.

Posted by Frank Roylance at 2:45 PM | Permalink | Comments (0)
Categories: Watches and warnings
        

The National Weather Service is predicting an afternoon high Monday of 78 degrees at BWI-Marshall Airport. That's not a record. But Sterling pretty regularly underestimates high temperatures for Baltimore, so there's a good chance the airport will see something more than 78.

The record for Baltimore on an April 4 is 83 degrees, set in 1956. It just happens to be the lowest daily high-temperature record on the books for April, so it's low-hanging fruit. 

The forecast calls for mostly sunny skies today. The April sun is strong, so provided clouds don't dim the afternoon rays, we could well slip into the low 80s for the second time this year. The first, you'll recall, was the record high of 81 degrees, reached on March 18.

The welcome mild weather is the result of a warm front that passed through the region overnight. It is the precursor of a Midwest cold front that is approaching the Appalachians to our west. Its approach will be marked by gusty winds, showers and possibly thunderstorms, most likely after 11 p.m. Up to a quarter-inch of rain is possible, with more in thunderstorms. Damaging wind gusts and heavy rain are also in the cards tonight.

The front is due to pass over the Chesapeake Bay around sunrise Tuesday. Showers and storms are forecast to linger into the day, with another three-quarters of an inch of rain possible. Behind it they're expecting brisk northwest winds. They will begin to dry things out, clear the skies, and cool daytime highs back down to about 60 degrees for Wednesday.

Thursday remains sunny in the forecast, with highs warming to the mid-60s. But there's another chance for rain with a cold front due to pass by Friday afternoon and evening. If the forecast holds up, Saturday will bring mostly cloudy skies with highs in ther mid-60s. Sunday brings another chance for rain, but with milder temperatures in the mid-70s.

Posted by Frank Roylance at 10:33 AM | Permalink | Comments (1)
Categories: By the numbers
        

FROM TODAY'S PRINT EDITIONS:

Carl Yowell, in Woodstock, writes: “Is there a web site which will give me daily, monthly and year-to-date rainfall totals for my local area?” The best one I know of is the CoCoRaHS Network (www.cocorahs.org) Just click on “View Data,” then “Total Precipitation Summary.” Select your state and county, and the date range you want to see, then “Search.” It’s not perfect; these are volunteers, and some don’t report every day. But it can be a rich source of very localized precipitation data. Good luck.

UPDATE, 11:30 a.m. Monday: Found this note in my inbox this morning from Allen Myers:

"Another good website for local weather is: weatherunderground.com  After you type in your town, you get the local weather as well as a list of 'backyard' weather stations that give minute-to-minute weather updates as well as their daily, weekly, and monthly weather history."

Thanks for that. I should have mentioned it myself, since The Sun's weather station is among those using Weatherunderground's platform. To see it, click here.

(SUN PHOTO: Karl Merton Ferron, October, 2010) 

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Categories: From the Sun's print edition
        

Fans headed to Camden Yards for the Orioles' home opener Monday can plan on temperatures in the mid-70s, with partly sunny skies for the hours they'll be in the stands. But the weather will be going downhill during the evening.

The National Weather Service said there is a 30 percent chance of showers overnight into Monday, so the ushers may need to wipe of the seats for you if the sunshine and wind haven't evaporated all the moisture by game time. 

But as the high-pressure center that brought us such welcome sunshine on Sunday moves out over the Atlantic Sunday night, it will be replaced by low pressure moving into the Great Lakes.

That will draw a warm front north during the day and, along with a strong April sun, will drive our afternoon temperatures into the 70s on strong southerly breezes. Some locations could see the upper 70s to near 80 degrees, and wind gusts to 30 mph.

The mercury should still be in the 60s at Camden Yards by the time the game ends. But a strong cold front approaching behind the warm air will begin to touch off showers and thunderstorms late in the evening, forecasters said.

The front should reach Baltimore and the I-95 corridor by midnight. Expect gusty, perhaps damaging winds with the front. Rain could be locally heavy in thunderstorms, with some risk of flash flooding.

The showers and storms could persist into early Tuesday. Daytime temperatures will hold in the 50s with strong breezes and gusts as high as 36 mph.

It will be sunnier, but not nearly as warm for the Orioles' second home game against Detroit, on Wednesday. The forecast calls for mostly sunny skies and highs near 60 degrees. 

(SUN PHOTO: Lloyd Fox, April 1, 2011)

Posted by Frank Roylance at 3:51 PM | Permalink | Comments (0)
Categories: Forecasts
        

FROM TODAY'S PRINT EDITIONS:

Saturn is at opposition at 8 p.m. tonight. That means it’s visible all night when skies clear, rising in the east as the sun sets. Look for a yellowish “star” with a steady shine. Opposition is also the planet’s closest approach to Earth this year – about 801 million miles away. It’s the middle of the best time of the year to see Saturn, and its iconic ring system, in a telescope. Try the Maryland Science Center’s Stargazing Fridays. Call 410 545-2999 Friday after 5 p.m.

(NASA PHOTO)

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Categories: From the Sun's print edition, Sky Notes
        

FROM TODAY'S PRINT EDITIONS:

(SUN PHOTO: Amy Davis, April 9, 2000)

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Categories: From the Sun's print edition, Sky Notes
        

FROM TODAY'S PRINT EDITIONS:

If March seemed unnecessarily dank and dreary, that may be due in part to the final week of unseasonably cool and drippy weather. We did reach a record high of 81 degrees, after all, on the 18^th. And half the days did average above the norm for Baltimore.

But we could have used more sunshine. The National Weather Service rated only three March days as “clear.” And we had a surplus of rain. We even set a new record for rainfall on a March 10 in Baltimore – 2.61 inches.

(SUN PHOTO: Karl Merton Ferron, March 18, 2011)

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Categories: From the Sun's print edition