|Dew Point:||31.0°F (-0.6°C)|
|Sea Level Pressure:||26.41" (894.2 mb)|
SunnyHigh: 37 Low: 28
Mostly Cloudy then Light Rain LikelyHigh: 41 Low: 35
Chance Light RainHigh: 46 Low: 36
Light Rain LikelyHigh: 48 Low: 35
Chance Rain And Snow ShowersHigh: 39 Low: 8
Sunny, with a high near 37. West wind around 8 mph.
Partly cloudy, with a low around 28. West wind 3 to 9 mph.
Rain likely after 2pm. Mostly cloudy, with a high near 41. South wind around 7 mph. Chance of precipitation is 60%. New rainfall amounts less than a tenth of an inch possible.
Rain likely. Mostly cloudy, with a low around 35. Southwest wind 7 to 12 mph. Chance of precipitation is 60%. New rainfall amounts less than a tenth of an inch possible.
A chance of rain before 1pm. Partly sunny, with a high near 46. Northwest wind 8 to 12 mph. Chance of precipitation is 30%.
Mostly cloudy, with a low around 36.
Rain likely after 7am. Cloudy, with a high near 48. Chance of precipitation is 70%.
Rain before 1am, then rain showers. Cloudy, with a low around 35. Chance of precipitation is 80%.
Rain showers before 9am, then a chance of rain and snow showers. Partly sunny, with a high near 39. Chance of precipitation is 80%.
... Dry high pressure will continue seasonal weather into Thursday. A weak cold front will cross the area Thursday night...before a stronger and wetter system affects the region over the weekend. Very cold high pressure will build across the southeast early next week.
NEAR TERM /THROUGH THURSDAY/... As of 205 PM EST Wednesday: Short wave ridging tonight will move east Thursday replaced by a short wave trough moving in from the west. Weak high pressure builds in from the northeast tonight before a weak surface low moves east into the Great Lakes region dragging a cold front into the Ohio and Tennessee valleys. Expect mainly cirrus overnight. However, there could be low clouds forming toward daybreak as weak isentropic lift develops along with some increase in low level moisture. There will likely be fog or low clouds in the mountain valleys and upper Savannah River valley. Lows tonight will be near to slightly above normal.
Although there is an increase in low level moisture Thursday morning ahead of the cold front, deeper moisture and better isentropic lift doesn't move in until the afternoon. Keep PoP low until then with a quick ramp upward across the area during the afternoon. As for p- type, precip should be rain, possibly mixed with a little sleet at onset as wet bulbing occurs, for most locations. The exception is the northern mountains where profiles and surface temps will be cold enough for some type of mixed precip before warming occurs changing the precip to all rain. The GFS has come in colder than previous runs and shows snow changing to rain. The NAM has been more consistent showing a strong warm nose with snow/sleet changing to freezing rain then rain. This is even with the precip onset mainly late morning to early afternoon. Using a blend, the forecast shows a sleet/freezing rain mix changing to freezing rain then rain. Either way, given the light QPF and strong warm nose, any sleet accums or ice accretion will be very light and limited to the higher elevations. Highs will be up to 5 degrees below normal.
SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... As of 245 PM Wednesday: Shower activity is expected to gradually diminish Friday morning with possibly a few lingering showers into the afternoon at the NC/TN line as the short wave associated with the weak system pushes off the Carolina coast. Cannot rule out snow or sleet briefly mixing in with the showers across the northern mountains, although impacts would be minimal if any. Left over low level moisture may support low clouds or fog for some areas and may delay diurnal heating a bit. Otherwise mostly sunny skies are expected by the afternoon, except in the mountains near the TN border where partly to mostly cloudy skies may persist. Highs Friday are expected to be several degrees above normal with highs in the 50s to near 60. Weak northwest flow turns southwest Friday evening and night with increasing moisture initially aloft in advance of the next storm system. This will support increasing high clouds Friday night. This combined with increasing warm air advection with support low temperatures about 10 degrees above normal with 40s for many areas especially outside of the mountains.
A vigorous southern stream shortwave trough over the Rockies to begin the short term Friday will drop southeast while gradually phasing with northern stream energy Saturday, supporting deepening of the trough across the Mississippi Valley. Southerly flow will develop and strengthen fairly rapidly Saturday in advance of the associated cold front pushing east through the Gulf Coast states. This will support continued increasing mid to eventually low level clouds with light rain developing first across the southwest mountains early in the day, spread across most of the region by Saturday evening. All rain is expected as the FA will be in the warm sector of the storm. Amounts will generally be light through Saturday evening. Highs Saturday will be largely dependent on the onset of rain with the current forecast going with highs generally in the 50s. Breezy southerly winds are likely across higher terrain by Saturday evening with gusts in excess of 30 mph likely.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... As of 200 PM Wed: Though some timing differences remain, the major global models have converged on a solution featuring northern- and southern-stream shortwaves coming into phase as they swing into the eastern CONUS late in the weekend. The result is a full-latitude trough reaching the Eastern Seaboard by early Monday. In response, from Saturday night onward, a deep sfc low will drive from the Tennessee Valley toward the New England coast. A powerful cold front, arguably the strongest we have experienced this winter, will push thru the CWFA early Sunday.
The FA will be in the warm sector at the start of the period (00z Sun), with rainfall rates coming to a head soon thereafter as the sfc front enters the area along with strong divergence/DPVA aloft. The EC and Canadian are a few hours slower than the GFS in bringing in the cold front, so our fcst PoPs will decline a bit more slowly east of the mtns than the GFS would suggest. That said, the necessary ingredients for a quick-hitting northwest flow snow event still look like they will come together for a brief time early Sunday, while moisture and cold air overlap. The strong upslope winds appear to be a lock based on the global model consensus, which will occur in conjunction with the aforementioned DPVA. Backward trajectories and 925/850mb wind fields suggest parcels will have passed over the eastern Great Lakes, a phenomenon associated with more efficient snowfall rates. Favorable upslope winds continue later Sunday, though moisture does become a bit questionable, particularly if the drier low levels depicted on the EC verify. That said, the rapid cooling aloft suggests the remaining moisture at that time will be at temperatures favorable for snow growth. We will prudently advertise only a gradual decline in PoPs into late Sunday. Event total snowfall right now looks like it eventually may warrant a Winter Weather Advisory for the mtns, but there is plenty of time for values to change. Our attention for impact weather then turns to the bitterly cold air pushing into the region. Sub-zero wind chills are expected across much of the mountain zones Monday morning. Temps Monday have been leaned in favor of the colder ECMWF numbers, which verified better than the common blends in our last major Arctic outbreak. Maxes look to be 10 to 15 degrees below climo.
A shortwave ridge is expected to return to the East on Monday, setting up over the Atlantic coast and inducing return flow by Tuesday. Another baroclinic zone develops on the upstream side of the ridge, and the next deep shortwave spins up a sfc low over the central CONUS by midweek. Models differ on how fast the return flow reintroduces precip into our area ahead of that system, and accordingly on the timing of the system itself. Confidence is low in the advertised PoPs and p-types ahead of it. Again the GFS is the fastest model of the set, but at any rate the primary effects of the system are expected to be after the end of the fcst period, Wednesday or Thursday. Temps do look to moderate back to about normal by Wednesday.