... A disturbance will exit the area this evening. Cooler air returns for Thursday, remaining through the weekend. Gusty northwest winds increase Thursday and will remain gusty through Friday, eventually settling down for the weekend. Showers return Saturday and Sunday.
NEAR TERM /THROUGH TODAY/... As of 1235 AM EDT Thursday...
...Back edge of precipitation moving through the area...
Radar showed to distinct area of light rain showers moving through the area. The first was mainly along and east of line from Lynchburg to Danville. The second was fairly narrow and extended from roughly Covington to Wytheville to Boone. Between the two areas of precipitation was cloudy skies with perhaps some patchy light drizzle.
As we progress into the early morning hours, increasing northwest wind and drier air arriving into the region will help erode the second area of precipitation as it progresses eastward.
Have made only limited changes to hourly temperatures, dew points, winds/gusts, and sky grids through the next few hours based upon the latest observations and expected trends.
As of 720 PM EDT Wednesday...
Severe threat has ended.
Deep convection has exited the forecast area, with frontal induced showers remaining. With so much cloud cover and showers, airmass has stabilized such that thunderstorm chances are weak. Could see some in the piedmont til 10pm with very limited CAPE but nothing strong or severe.
Most places west of the Blue Ridge will dry out by midnight or shortly thereafter with lingering showers through the morning in the piedmont. Fog may become an issue if we clear out enough, especially along the river valleys.
Current visible satellite this afternoon showing quite a bit of clearing over the CWA. Areas that have cleared have had temperatures jump to near 80F already, especially northern North Carolina and southern portions of Virginia. Still expecting thunderstorm development later this afternoon into early evening as an upper- level impulse moves across the area during peak heating.
Although low-level moisture is still rather modest(i.e. dew points in the upper 40s to low 50s) and afternoon temperatures now pushing well into the 70s to near 80F should still at least marginal instability across the CWA. This, along with supportive shear profiles and model hodographs showing some low-level turning could provide for a couple stronger storms to develop, mainly between 18- 21Z/2-5PM becoming more organized as it moves east into the Piedmont. Storms will remain elevated and any stronger storm will be capable of hail and damaging winds.
Severe threat should be winding down by 00z, with mainly just some light rain remaining over the area, tapering off to drizzle through Thursday morning. Along with gradual clearing, cooler air is ushered in behind the system, with temperatures tomorrow 10-15F cooler than what we are seeing this afternoon. Will also see an increase in winds out of the northwest with a marginal low-level jet increasing overhead through Thursday afternoon, along with decent 850mb cold air advection. Could see some gusts in the 25-35mph range, especially for the higher elevations.
SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... As of 200 PM EDT Wednesday...
Cool and unsettled into the weekend.
Guidance continues to show good agreement with reinforcing an upper trof in the eastern US with a series of short waves rotating around. This will favor cool conditions with some precipitation.
Thursday night will see gusty winds especially wets of the Blue Ridge with moisture wrapping around low pressure moving slowly up the New England coast. There may be enough moisture to generate some upslope sprinkles or even some wet snow showers at the higher elevations west of the Blue Ridge. Moisture wanes a bit on Friday but diurnal heating under the pool of colder air aloft will generate some cumulus clouds and limit sunshine especially in the mountains. Another series of short waves then moves through the region on Saturday and again on Sunday into Sunday night. This will be enough to keep some showers around throughout the weekend with maybe a few wet snowflakes on the hilltops.
Expect temperatures generally 5 to 10 degrees below normal into the weekend. Expect highs low/mid 50s west of the Blue Ridge but cooler on the hilltops, and low/mid 60s to the east. Lows generally in the 30s west but cooler in the valleys, with upper 30s/lower 40s east. Have to watch for some patchy frost in the east if a window develops where winds subside and clouds can clear out for a few hours especially Friday night.
LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 205 PM EDT Wednesday...
Not anticipating any change in the large scale pattern.
Synoptic scale pattern retains broads troughing in the central and eastern United States with somewhat separate northern and southern streams. Challenging to narrow down mostly likely time frame for any organized precipitation. ECMWF/GFS and Canadian have short waves crossing the southeast United States Sunday and Monday. Mid Atlantic region looks to be on the northern side of precipitation with these features. Tuesday should be a day with a lower probability of rain then Wednesday a stronger cold front crosses the area. A wave of low pressure along the front may mean the timing slows down in subsequent forecasts. But a better probability of precipitation will accompany the front whenever it cross the Mid Atlantic states and Carolinas.
Overall, the upper flow is zonal enough to keep temperatures from being extreme, neither unseasonably warm nor cold.