|Dew Point:||-1.5°F (-18.6°C)|
|Wind:||From the NE at 3.1 MPH Gusting to 6.0 MPH|
|Wind Chill:||2°F (-17°C)|
|Sea Level Pressure:||30.24" (1023.9 mb)|
Partly CloudyLow: 4
M.L. King Jr. Day
SunnyHigh: 14 Low: -1
Mostly SunnyHigh: 33 Low: 26
Light RainHigh: 47 Low: 38
Light RainHigh: 42 Low: 23
Partly cloudy. Low around 4, with temperatures rising to around 10 overnight. Wind chill values as low as -8. Northwest wind around 17 mph, with gusts as high as 29 mph.
Sunny, with a high near 14. Wind chill values as low as -12. Northwest wind 9 to 17 mph, with gusts as high as 30 mph.
Mostly clear, with a low around -1. Wind chill values as low as -6. West wind 2 to 8 mph.
Mostly sunny, with a high near 33. Southwest wind 1 to 9 mph.
Mostly cloudy, with a low around 26. South wind 6 to 10 mph.
Rain after 7am. Cloudy, with a high near 47. Chance of precipitation is 90%.
Rain. Cloudy, with a low around 38. Chance of precipitation is 90%.
Rain. Mostly cloudy, with a high near 42. Chance of precipitation is 90%.
Rain likely before 7pm, then a chance of snow. Mostly cloudy, with a low around 23. Chance of precipitation is 70%.
... Arctic high pressure will build across the region through Tuesday. A cold front will move into the region Wednesday, with another area of low pressure moving across the area Wednesday night into Thursday.
NEAR TERM /THROUGH MONDAY/...
00Z IAD sounding showed winds in the mixed layer in the mid 30s, so let Wind Advisory expire. Although can't rule out sporadic gusts to 40 kts overnight, this should not be the norm. Used a blend of 12Z ECMWF and HREF for overnight temperatures, this means teens and single digits for most and below zero for the mtns. Wind chill values will be below zero everywhere and up to -30F in the mtns. Kept highs mainly in the teens tomorrow except low 20s across southern areas. Wind chills will be around zero during the "warmest" part of the day. Bottomline, it will be bitter cold next 24 hrs.
SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/... Blustery and very cold conditions persist into Monday with Wind Chill headlines continuing for the first half of the day. Despite mostly sunny skies, temperatures will struggle to rise, and highs will hold in the teens/20s.
The coldest night air-temperature wise (sans wind chill) will be Monday night as ~1040mb high pressure moves directly overhead. Near-ideal radiational cooling conditions will allow for lows to bottom out in the single digits for most locations, except below zero in the coldest locations of the Potomac Highlands and Shenandoah Valley, and in the teens in the urban centers and along the larger bodies of waters.
The high pressure will slide off to the south/east Tuesday, promoting the development of a southerly return flow. With sunshine, this will allow for rapid moderation of the air mass, and highs will be back in the 30s.
Southwest flow and warm air advection will intensify Tuesday night out ahead of an approaching frontal system. Clouds will be on the increase and some light precipitation becomes possible by morning west across portions of WV and western MD. Dependent on the amount of remaining cold air and when precipitation can start, some light freezing rain/sleet is possible.
LONG TERM /WEDNESDAY THROUGH SUNDAY/... High pressure will slide further offshore on Wednesday as a front approaches from the west. Warmer air should have spread across the region by this point, but some icy precip is not impossible early in the day. The front will stall over the region Wednesday night as one wave of low pressure passes well to our north and another develops over the Southeast and rides northeast up the front. As the wave crosses our region early Thursday, a period of heavy rain is possible, with potential for a bit of wintry weather towards the back side. Guidance has not quite settled on the exact track of the low, so this will influence future temperature and p-type forecasts, but odds favor rain for the metro, with a better chance of wintry weather well north and west. Dry weather should return behind the system Thursday night along with cooling temps.
Another front, this one more arctic in origin, will cross the region Friday. There is some potential for snow showers/squalls with it based on the latest GFS, but other guidance is not as robust with it. Behind this second front, arctic high pressure will then settle over or just south of the region for Saturday, resulting in a very cold start to the weekend. Another system will approach Saturday night, but this looks weak. With cold temps, however, whatever falls would likely be snow.