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November 25, 2008

"Dry slot" brings us sunshine; Garrett gets snow


Meteorologists call it a "dry slot" - an intrusion of clear, dry air, drawn into the swirling clouds around a spinning low pressure system. There's one over Central Maryland this morning. as the satellite image above shows quite well. And that dry slot is what's brought us this delightful sunny morning.

The low is centered over the Great Lakes. As it spins in a counter-clockwise direction, it is bringing winds here from the north and west. And that's going to mean more snow for the far western counties of Maryland., where the morning looks far different than ours at the moment. 

Taylor Made VacationsThe National Weather Service forecast office in Pittsburgh has issued a Winter Weather Advisory for Garrett, from noon today through noon Wednesday. They're told to expect 4 to 6 inches of new snow before the storm tapers off tomorrow. Some higher elevations could see 8 inches.

Far western Allegany County, including the town of Frostburg, are also under a Winter Weather Advisory issued from Sterling. Lake effect snow showers are expected there from 11 a.m. today through 1 p.m. tomorrow. Accumulations of "up to 7 inches" are possible in some locations.

Looks like the snow is already falling at Deep Creek Lake. Here's a shot from the Taylor Made Vacation Rentals Web cam.

In the meantime, there's no dry slot over Ocean City, where it was gray and rainy this morning. Here's the Kite Loft Web cam.


Posted by Frank Roylance at 10:21 AM | | Comments (1)
Categories: Forecasts


"Meteorologists call it a "dry slot" - an intrusion of clear, dry air, drawn into the swirling clouds around a spinning low pressure system."

The 'dry slot' comes about because the air stream in that quadrant of the cyclone is descending and descending motion suppresses cloudiness from adiabatic warming.

Elsewhere in the immediate vicinity of the storm...the atmosphere/s motion is upward...which produces clouds and precipitation from adiabatic cooling.

FR: Thanks for the scientific input.

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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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