A cold front will sweep east across the area late tonight, with a reinforcing arctic front following Monday night. High pressure then returns for the middle to latter half of next week.
Until 6 am Monday morning As of 7 PM Sun, Forecast largely remains on track as of the 7 PM update. Expectation continues to be for scattered to numerous rain showers to overspread the area over the next several hours. Forecast soundings suggest ample inhibition near the surface, but the presence of elevated instability will support the potential for an embedded thunderstorm or two. There is a low (<5%) chance for a stronger thunderstorm capable of producing an isolated strong wind gust (40-60 mph) and small hail, but the overall severe risk is LOW.
Previous Discussion, Front enters the FA from the W around midnight with nearly meridional flow from midlevel up as upper low digs S across Great Lakes and Indiana, pushing upward leg of trough aloft across the wrn half of NC through the overnight. Convective precip is expected ahead of the boundary as it races across the FA. Some instability will remain from this afternoon's heating and the ample speed and directional sheer will keep a chance of more organized cells to carry some threat of damaging wind gusts with a lower, but non-zero threat, of hail. Temp gradient will be tight behind the front with burst of initial CAA leading to temps cooling into the 45-50 range over the Coastal Plain in the early morning hours, 50-55 coast. Precip wanes from W to E in the early morning hours, but not directly behind the front as moisture still streaming in from the S above the frontal inversion will lead to some stratiform rain expected behind the front through around sunrise on the OBX.
6 am Monday morning through 6 pm Monday As of 3 PM Sun, Transition day in store as initial front that passes tonight brings cooler air into the region. Thicknesses support max T's in the mid 50s interior, to close to 60 coast, or about 10 degrees below climo. Skies start out partly to mostly cloudy, but rapid clearing on downsloping arridifying air off the Appalachians throughout the day expected.
Monday night through Sunday As of 3 PM Sun,
Key Messages
- The coldest air of the season arrives Monday night into Tuesday.
- Freeze warning now in effect for most of Mainland ENC, with watches continuing near coast.
- Scattered non-accumulating light snow or flurries possible late Mon night.
Mon Night, Reinforcing arctic cold front moves through Mon night. With this arctic wind surge, gusty winds and plummeting temps expected. A good chance for a freeze for much of inland ENC, with upper 20s to lower 30s expected. Closer to the Crystal coast and other coastal zones, more marginal temps expected. A strong breeze will prevent radiational cooling, but either way, areas that don't get a freeze will feel like they're well below freezing due to the gusty nwrly breezes.
Other than the cold, beneath the upper low which, in conjunction with a stout embedded midlevel shortwave traversing the region, may support brief ra/sn to light snow or snow showers/flurries. Have cont 20-30% pops, highest along the Hwy 64 corridor, where a light dusting on grassy areas may occur. Certainly no accums on roads and therefore just mentioning novelty flakes in the fcst. Elsewhere, some snow flurries may make it to the ground all the way to the Crystal Coast.
Tuesday-Tuesday Night, Thicknesses/hts bottom out on Tue, with highs only in the 40s area-wide, some 20 degrees below climo. Some question on how quickly return flow can develop on Tue night. There is a window for the coldest night of the season to fall along the mainland coastal zones if winds can stay calm to light. Have lows around freezing for the Crystal Coast through Mainland Dare. If winds pick up too quickly, as they are expected to gradually inc out of the SW with swrly gradient picking up, a freeze here could be prevented.
Wednesday through Sunday, High pressure remains centered across SECONUS Wednesday with southerly flow bringing warming temperatures, but still ~5 degrees below normal with highs in the lower 60s. A mid level shortwave pushes across the Mid- Atlantic Wednesday night with an attendant sfc trough/front pushing through the area, however the airmass remains very dry and don't expect much in the way of clouds, let alone precip, with this system. Deep westerly downslope flow ahead of ridging sliding across Sern CONUS will actually bring a few degrees of warming temps on Thursday with highs expected in the mid 60s. High pressure builds into the area Friday before sliding offshore first half of the weekend with highs in the low to mid 60s.
00z Monday through Friday As of 7 PM Sunday,
Key Messages
- TSRA possible this evening (20-40% chance) - Brief MVFR conditions likely this evening into tonight for coastal terminals - Periods of gusty winds through mid-week
Southwesterly winds of 5-10 knots will continue ahead of a cold front approaching from the west. Expectation is for scattered to numerous showers to overspread ENC over the next few hours, with an embedded thunderstorm or two possible (20-40% chance). Heavier showers/thunderstorms may bring temporary VIS/CIG reductions, but generally expect VFR conditions to persist. There is a low chance (<5%) for a stronger thunderstorm that could produce a stronger wind gusts (40-60 mph) or small hail. Cold front then pushes through ENC overnight, with winds becoming northwesterly around 10 kts with gusts to 15-20 kts. Guidance indicates there will be a brief period of MVFR conditions for coastal terminals of OAJ/EWN after midnight tonight, but do not expect these reductions to last more than a few hours. Chances for IFR ceilings are currently LOW. Drier air moving in behind the front will then reduce chances for showers and lower ceilings beginning early tomorrow morning, with VFR conditions returning to TAF sites for the day.
Outlook: VFR conditions are expected for much of the upcoming work week. The one exception is Monday night as a secondary cold front moves through with the potential for a brief round of low CIGs and SHRASN. Should any SN occur, it is expected to be brief with no accumulations, and mainly confined from KPGV east through KFFA. A period of gusty west winds is expected Tuesday, followed by gusty southerly winds on Wednesday.
Monday through Saturday .. As of 7 PM Sun, Previous forecast remains on track. Only adjustment as of 7 PM Sunday was to bump up wind gusts tonight as winds have been slightly overperforming. Observations have shown occasional gusts to 25 kts across the coastal waters south of Cape Hatteras. Overall, gusts are expected to largely remain sub-SCA conditions, but occasional gusts to 25 kts will remain possible tonight and into tomorrow morning.
Previous Discussion, Gale watches upgraded to warnings, with SCA in effect for the Albemarle/Croatan/Roanoke sounds and the rivers.
A cold front moves through early tomorrow morning, with swrly to wrly breezes becoming nwrly and ocnl gusting to 25 knots, esp on the waters. Much stronger reinforcing arctic front still on track to move through later Mon night, with gales expected late night into first part of Tue. Seas build as high as 6-9 ft for the waters s of Hatteras. Winds relax a bit Tue night, but reinforcing gradient on swrly winds expected Wed, and could see some gales again south of C Hatteras once again.
Winds and seas finally begin to lay down by Thursday as high pressure builds over SECONUS eventually sliding off the coast first half of the weekend.
Nc, freeze warning from 2 am to 8 am EST Tuesday for ncz029- 044>046-079>081-090>092-094-193-194-198-199. Freeze watch from late Monday night through Tuesday morning for ncz047-195-196. Marine, small craft advisory from midnight Monday night to 4 pm EST Tuesday for amz131-136-137. Gale warning from 2 am to noon EST Tuesday for amz135. Gale warning from 4 am to noon EST Tuesday for amz150. Gale warning from midnight Monday night to noon EST Tuesday for amz152-154-156-158. Small craft advisory from 7 pm Monday to 4 pm EST Wednesday for amz230-231.
