textproduct: NWS Wilmington

WHAT HAS CHANGED

Severe Thunderstorm Watch has been cancelled for the entire area.

Aviation discussion updated for the 18Z TAFs.

KEY MESSAGES

1) Much colder and drier weather will continue to arrive behind a strong cold front this afternoon through tonight.

2) A strong cold frontal passage Monday and Monday night will bring another sharp cooldown through mid next week.

DISCUSSION

KEY MESSAGE 1...Much colder and drier weather will continue to arrive behind a strong cold front this afternoon through tonight.

A good 20 to 30 degree temperature drop will take place by this evening across much of the Carolinas as plenty of dry and cold air moves in behind exiting cold front. Pcp water values up around 1.5 inches ahead of front will drop to less than a quarter of an inch by this evening. Temps will be down in the 40s by this evening across the area and down in the mid 30s most places for lows. Skies will clear and winds will drop through the night as high pressure migrates overhead, and any wind sheltered spots could see temps drop below freezing. Frost is also possible in spots.

KEY MESSAGE 2...A strong cold frontal passage Monday and Monday night will bring another sharp cooldown through mid next week.

A big change in the weather pattern is expected starting Monday as an anomolously strong deep upper trough develops to the west around the MS Valley and then shifts eastward through mid week, albeit in a weakening state. Temperatures will go from above normal Monday to below normal Mon night and stay that way through Thursday. There looks to be a very low risk for a light freeze well inland Mon night, with a better risk for a widespread freeze Tue night. Temps should be a bit warmer Wed night but still in the mid 30s with some frost potential. Note that our local frost/freeze program does not typically start until Mar 21 so unless that changes we will not be issuing any frost/freeze headlines through this period.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

A strong cold front accompanied by lingering area of showers moving through the eastern half of area will move off the coast between 19z and 21z. Lingering areas of MVFR in lower ceilings will transition to VFR by 22 to 24z with strong gusty winds continuing into this evening. The cold front will clear the coast mid to late afternoon, with pcpn ending and rapidly clearing skies. Gusts to 45-50 kt in shifting SW to N winds ahead and behind front into late afternoon. By 03z, most winds should be less than 10 kts out of the north as the center high pressure moves quickly overhead.

Extended Forecast...VFR is expected Friday through the first half of the weekend. Flight restrictions are possible due to increasing rain chances Sun into Mon as the next frontal system affects the area.

MARINE

Through Friday...Tightened gradient flow and CAA will keep Gale conditions ongoing through late this evening as cold front moves through. SW winds ahead of the front will gust to 35 kts or so and will continue with N winds behind the front into this evening. Winds will diminish and continue to veer to the N and then E as high pressure moves closer overhead. Seas up to 4 to 7 ft with a few 8 fters in the outer waters will diminish as winds drop off overnight tonight. By Fri seas will be down to 2 to 4 ft with winds becoming onshore 15 kts or less.

Friday night through Tuesday...No big changes to the previous forecast with moderate confidence through the period. High pressure will give way to a strong cold front late Monday and Monday night. Small Craft Advisory conditions are possible from late Sunday into early Tuesday. There is also a low risk for gale force gusts, especially Monday/Monday night.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...Gale Warning until midnight EDT tonight for AMZ250-252-254-256.