textproduct: NWS Wilmington

WHAT HAS CHANGED

As of 1000pm...Cancelled the Small Craft Advisory for SC coastal waters from Little River Inlet to Murrells Inlet out 20nmi as wave heights continue to decrease while the other coastal waters have seen their Small Craft Advisory extended until 10Z as 6 ft seas are expected to linger a bit longer than originally forecast.

As of 745pm...Aviation discussion updated for 00Z.

As of 150pm... No significant changes. Aviation section updated to include routine 18Z discussion.

KEY MESSAGES

1) Patchy frost possible tonight in our normally chilly spots.

2) Above normal temperatures are expected ahead of a strong cold front on Friday. Showers and a stray thunderstorm are possible with the cold frontal passage, but confidence remains low.

DISCUSSION

KEY MESSAGE 1: Patchy frost possible tonight in our normally chilly spots.

High pressure over the Ohio Valley will move east and off the MidAtlantic Coast tonight. This airmass has kept temperatures well below normal today and it will continue to do so tonight. With our growing season already declared underway this opens up the concern for frost/freeze. Luckily no guidance is supportive of the latter, even the NBM 10th percentile guidance. Our normally soil-induced cold spots in Pender and Bladen Counties look to drop down to about 36 and should have patches of predawn frost.

KEY MESSAGE 2: Above normal temperatures are expected ahead of a strong cold front on Friday. Showers and a stray thunderstorm are possible with the cold frontal passage, but confidence remains low.

A strong cold front will approach during the latter half of the week, bringing significant warming to the region with high temperatures up to 10 degrees above normal on Friday. High temperatures for our inland locations could approach records. Coastal areas will be moderated by a cooling sea breeze.

Record highs for 3/27 Florence, SC: 89 in 2021 Lumberton, NC: 87 in 1950 & 1949

A stray thunderstorm is possible as the cold front drifts southward late Friday, but chances remain very low. In general, ensemble rain chances held steady from the previous forecast. Despite the slight increase in our deterministic forecast, confidence remains low in a few showers developing along the front late Friday. The best chance for precip (in our CWA) will likely exist over portions of southeast NC.

AVIATION /01Z WEDNESDAY THROUGH SUNDAY/

VFR is expected to prevail through the period. The 4-5kft cloud deck affecting the Myrtles should linger for several hours more before thinning out later tonight. In addition, scattered to broken low clouds are approaching Cape Fear and may also bring transient ceilings that should be around 4kft at the lowest. East-northeast winds will weaken considerably early tonight and back to northeast. Broken to overcast high clouds will arrive from the northwest after dark and continue into Wednesday morning. With high pressure moving offshore north of the area tomorrow, expect winds to veer to between east and southeasterly during the afternoon. Dry air and subsidence will preclude any vis or cig concerns during this period. Some flat cumulus is expected to develop tomorrow, but the bases should stay predominantly above 3kft.

Extended Forecast... There is a low chance of ground fog Thursday morning, otherwise VFR conditions should prevail through Friday. The next cold front should reach the area Friday night accompanied by a substantial wind shift and possible thunderstorms. VFR conditions should return on Saturday as much drier air filters in behind the cold front.

MARINE

Through Wednesday... The gradient remains rather tight between high pressure in the Ohio Valley and the very strong cold front that blew through yesterday, the boundary now well offshore. The post-frontal high will progress eastward through the near term keeping winds and seas to advisory levels through a good portion of tonight. The current 2AM expiration of the SCA is likely pessimistic but will let evening shift reassess. With the center of the high moving off the MidAtlantic Coast Wednesday winds and seas will continue to abate.

Wednesday Night through Saturday... Lighter winds are expected on Wednesday night as high pressure builds over the Carolinas through early Thursday. An afternoon sea breeze will yield to southerly winds late Thursday afternoon and Thursday evening as that same area of high pressure shifts offshore.

Established SSW flow will increase Thursday night in advance of an approaching cold front. SCA conditions are possible as early as Friday night prior to the northerly wind shift. Stronger winds aided by cold air advection early Saturday should easily push our area beyond the SCA threshold with both winds and 6-foot seas. A few gusts could reach gale force, but confidence is low regarding their frequency and duration.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...Small Craft Advisory until 6 AM EDT Wednesday for AMZ250-252- 256.