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April 12, 2011

Friday/Saturday rain could be heavy

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.

cherry blossomsOnce 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 | | Comments (1)
Categories: Forecasts


I pray it comes late Friday night and early Saturday morning. The wife has been planning our charity golf tournament for three months to be played on Saturday! Say it ain't so...


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

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