|Dew Point:||°F (°C)|
|Sea Level Pressure:|
SunnyHigh: 73 Low: 49
Mostly SunnyHigh: 74 Low: 60
Chance Showers And ThunderstormsHigh: 81 Low: 65
Mostly Sunny then Slight Chance Showers And ThunderstormsHigh: 82 Low: 63
Slight Chance Showers And ThunderstormsHigh: 83 Low: 65
Sunny, with a high near 73. Northwest wind 3 to 7 mph.
Partly cloudy, with a low around 49. East wind around 5 mph.
Mostly sunny, with a high near 74. South wind 3 to 8 mph.
A slight chance of rain showers after 2am. Partly cloudy, with a low around 60. Southwest wind around 8 mph. Chance of precipitation is 20%.
A slight chance of rain showers before 8am, then a chance of showers and thunderstorms. Partly sunny, with a high near 81. West wind 7 to 13 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
A chance of showers and thunderstorms before 2am. Partly cloudy, with a low around 65. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
A slight chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 82.
A slight chance of showers and thunderstorms before 8pm. Partly cloudy, with a low around 63.
A slight chance of showers and thunderstorms after 8am. Mostly sunny, with a high near 83.
... High pressure over the Great Lakes will move east today and tonight, reaching the Atlantic coast by late Wednesday. Low pressure over New England will push a cold front close to the region on Friday, otherwise the Mid Atlantic area will remain in above normal temperatures with limited organized rainfall through the weekend.
NEAR TERM /THROUGH TONIGHT/... As of 330 AM EDT Tuesday...
500MB heights rise over the Mid Atlantic region as the upper amplifies and ridging builds along the southeast United States coast.
Bufkit forecast soundings showed a layer of warm air around 800MB which will cap any vertical growth in cloud cover. In addition, mid and low levels will be dry. Upslope is weak and shallow so expect clouds over western Greenbrier to erode during the morning. All of the region with have occasional high clouds blowing off from intense thunderstorms in the Plains and Mississippi Valley. Expect the high clouds to have little impact on heating and today's maximum temperature.
At the surface high pressure over the Great Lakes moves east into Pennsylvania and New York by late tonight. Surface to 850MB winds back to the southeast along the east slopes of the southern Blue Ridge overnight. Low clouds develop after midnight and fill in over the mountains and foothills by morning. Not a deep enough layer of moisture for drizzle but ridges will be in the clouds.
Surface dew points in the mid 40s to mid 50s overnight so with that kind of dew point depression temperatures will drop quickly after sunset and winds decouple. Favored sheltered valleys will be cooler than western ridges.
SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... As of 315 AM EDT Tuesday...
Through this portion of the forecast, an upper level ridge over the eastern U.S. will retrograde to closer to the Mississippi Valley. This will occur in a shortwave trough rounds the top of the ridge, and a longwave trough along the west coast of the U.S. opens and weakens a bit.
The shortwave that will challenge the location of the ridge will cross it Wednesday night into Thursday. Just in advance of this feature, there will be a pooling of low level moisture across the mountains with the potential for some diurnal isolated showers and storms across the far western portion of the forecast area. The shortwave itself will head southeast through the mid-Atlantic region, helping to shunt southward a backdoor cold front towards our area. This feature will act as focus for a better chance of showers and storms across the region, especially across the north, late Wednesday night into Thursday.
Thursday night through Friday night, the backdoor cold front either washes out or lifts slightly north all while northwest flow aloft becomes more established with the ridge now centered to our west. While precipitation chances will not be zero, they will trend to isolated coverage mainly over the mountains, and any shower or thunderstorm activity will be more diurnally and upslope driven.
Temperatures during this portion of the forecast will be near normal on Wednesday, but warm to readings 10 to 15 degrees above normal for Thursday and Friday.
Confidence in the above portion of the forecast is moderate, with the biggest challenge being the coverage and timing of any showers and storms.
LONG TERM /SATURDAY THROUGH MONDAY/... As of 345 PM EDT Monday...
By the weekend, the ridge begins to shift a bit further west allowing the westerlies north of 40 degrees latitude to edge a bit further south. Over the weekend, a modest intensity short wave tracks along the Canadian border and across the Great Lakes. This will help to squash the ridge southward a bit and allow yet another backdoor front to slip southward toward the MD/PA border, possibly into northern VA. Just as with the front earlier in the week, this has the potential to fire convection in the highly unstable/warm atmosphere and some of this convection will slide southward during the afternoon and evening again most likely reaching the I64 corridor. So will ramp pops back up to chance levels again. The ridge will be a feature trying to suppress convection throughout the forecast time frame, so really do not want to go to high with pops. Throughout most of the period, keep the highest pops in the north furtherest away from the ridge and closest to jet stream dynamics off to the north. Monday, the ridge begins to amplify again as troughing digs into the Midwest, so convection Monday will tend to lift further north again or be confined mainly to areas of differential heating across the mountains.
Temperatures will remain about 10 degrees above normal through the period, but again with 850mb temperatures remaining mostly below 20C, we should top out in the 80s west to the lower 90s Piedmont most days of this period. Low temperatures will be mostly in the 50s and 60s, again somewhat above normal but not extreme.
/Confidence in Forecast Parameters/ Temperatures - Moderate, Precipitation Probabilities - Moderate, Winds - Moderate, Thunderstorm Probabilities - Moderate.