Sunny, warmer Thursday, 1-2" of rain possible Sat.
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
Comments
I'm sure the farmers love this weather....me? probably in the majority that just think it stinks.......this has been the worst March and April I can remember in recent memory....is it just me, Frank, or has the lat 45 days been unusually "gloomy"? Thanks.
FR: Not sure how it compares, really. But it was a pretty wet March, and we have had few truly "clear" days since March 1. At BWI, precipitation in March exceeded the average by an inch, and April is running about in step with the average so far. But the weather service counted only 3 "clear" days in March, with 11 rated "cloudy." April, through the 13th, saw no "clear" days at all, and 9 were rated "partly cloudy." BWI saw 15 days in March with at least a trace of precipitation, and eight so far in April.
Posted by: Rich | April 14, 2011 8:00 AM