WEATHER BLOG: Cool And Dry

Main weather focus for Wednesday evening will be on the degree of clouds and spotty showers. Radar shows measles like showers over the region. This is in response to an upper level impulse riding through the upper level trough. As this impulse moves over Maryland it will force the trough axis to move eastward. So, once this axis moves east of the area upper level winds will turn more out of the northwest and drier air will move in later Wednesday. This drier air will help bring a break up in the clouds and the sky should gradually clear through the early morning hours of Thursday. The wind will slowly drop off overnight. So, readings will drop into the 30s. We can still see a few spots well north and west of the Beltway dropping close to freezing tonight. Dewpoints and temperatures will be close enough for frost to form. But there might be enough of a breeze to prevent that from happening in most of the colder areas.

High pressure will build in from the north later Wednesday night and Thursday as the surface. This will help bring a dry and mostly sunny day Thursday. Given a mostly sunny sky temperatures Thursday will warm to near 60. But the air mass will still be quite cold, especially aloft. So, once the sun sets readings should fall quickly through the 40s then into the 30s Thursday night. Low temperatures Thursday night will range from near 30 in the colder areas well north and west to about 35 near the Beltway and 38 in the Harbor area. We see a day to day warm up Friday and Saturday as the surface high moves east and allows a more southerly flow of warm air to return. This will set the stage for some real nice weather for both Friday and Saturday.