|Dew Point:||35.0°F (1.7°C)|
|Wind:||From the West at 1.0 MPH|
|Sea Level Pressure:||26.83" (908.5 mb)|
Light RainHigh: 50 Low: 25
Slight Chance Light Snow then Mostly SunnyHigh: 38 Low: 26
SunnyHigh: 42 Low: 31
SunnyHigh: 50 Low: 40
Cloudy, with a low around 47. West wind around 12 mph.
Rain after 11am. Mostly cloudy, with a high near 50. South wind 5 to 9 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Rain before 11pm, then rain and snow likely. Cloudy, with a low around 25. Northeast wind 9 to 16 mph, with gusts as high as 25 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch possible.
A slight chance of snow before 8am. Mostly sunny, with a high near 38. Northeast wind 10 to 16 mph, with gusts as high as 25 mph. Chance of precipitation is 20%.
Mostly clear, with a low around 26. Northeast wind 9 to 13 mph.
Sunny, with a high near 42.
Mostly clear, with a low around 31.
Sunny, with a high near 50.
Mostly clear, with a low around 40.
... A weak warm front will approach the region tonight and then stall across the area. A low pressure system will track along this boundary Monday, bringing a cold front across the region late Monday afternoon into Monday evening. High pressure settle southward across the area for Tuesday through Friday.
NEAR TERM /THROUGH MONDAY/... Forecast issued earlier this afternoon remains largely on track, and only minor modifications were made for this evening's package.
High pressure has pushed into the Atlantic, which south flow across the area. Although the upper layers are moistening, the boundary layer is bone dry (relative humidity 20%/dewpoint depression near 40 degrees). Eventually, the veil of high clouds will thicken, and slowly lower tonight.
Weak positive vorticity advection and isentropic upglide will allow clouds to lower. However, given how dry it is below 850 mb, am less optimistic with respect to precipitation tonight. Am keeping a chance of rain northwest of Washington DC, but precipitation (sprinkles?) will barely be enough to wet the ground.
SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... The associated weak warm front will stall across the area Monday morning and then slowly drop south again as low pressure tracks across the area during the afternoon. Forcing from the low and 500 mb shortwave will be the catalysts for rainfall; this will occur during the afternoon hours, supporting likely- categorical PoPs. It may be just cloudy and damp prior to it. Do believe there will be a fairly sharp precip gradient near the Mason-Dixon line.
Although temperatures forecasts for Monday remain somewhat tricky due to the position of the warm front/track of the low, model output remain somewhat consistent resulting in only minor adjustments. Since it may not be all that wet early Charlottesville-Fredericksburg, and these locations should be on the south side of the system, anticipate central Virginia should be able to reach 60 degrees. The bigger question will be the Potomac Highlands; am keeping the forecast there lower-mid 50s. A wetter solution, especially in the morning, could make that forecast too warm.
Cold advection will arrive on the back side of the low Monday evening. There is a chance that temperatures will cool sufficiently to end the precip as snow, especially across the ridge tops, but do not have high confidence that there will be much precip left by that point (winds will be due north...not an upslope direction). Allowed for a coating on some ridges, but nothing elsewhere.
A large area of high pressure will settle south from the Great Lakes (and Canada) Tuesday. Subsidence will result in sunny and dry conditions, but it won't be warm. Highs will only be in the 40s (with subzero 850 mb temperatures) and lows Tuesday night in the 20s away from the urban downtowns.
LONG TERM /WEDNESDAY THROUGH SUNDAY/... Surface high pressure will push off the east coast on Wednesday, and remain there through the early part of the weekend. Additionally, the region will be stuck under an upper ridge, resulting in dry weather for the entire area through Saturday. Temperatures will moderate slightly on Wednesday, but will likely be slightly below average, with highs into the low to mid 50s. The warming trend will continue through Saturday. Highs on Thursday will be near 60, with Friday reaching into the mid to upper 60s.
Surface low pressure forms over the Central Plains Friday into Saturday as an upper shortwave ejects out of the Pacific Northwest. The low will then strengthen on Saturday as the aforementioned shortwave phases with another piece of shortwave energy diving out of central Canada. On Saturday, this will enhance the return flow for our region, resulting in temperatures well above normal. Could see high temperatures into the low 70s on Saturday, with dry conditions expected. Though, as the low tracks into the Great Lakes, the attendant cold front will push through our region either Saturday or Sunday. So, could potentially see some precipitation later in the day on Saturday, but uncertainty is still high in terms of timing of the frontal passage.