textproduct: NWS Wilmington

WHAT HAS CHANGED

Added 18Z TAF discussion.

KEY MESSAGES

1) Increased fire danger on Saturday.

2) Hazardous marine conditions expected tonight into Sunday.

3) Frost possible Saturday night away from the coast.

4) Chance for thunderstorms increases latter half of next week.

DISCUSSION

KEY MESSAGE 1...Increased fire danger on Saturday.

Post-frontal gustiness paired with strong cold and dry advection will make for enhanced fire danger Saturday. It's a rather marginal setup but with after coord with our state liaison offices, who collab with Forest Service the following headlines have been decided upon: The Fire Weather Watch has been upgraded to Red Flag Warning for SC, where there is also a state-issued ban on outdoor burning. Our NC counties will now highlight with a Fire Danger Statement, the decision whether to leave it or upgrade to RFW to be re- evaluated this evening and overnight.

KEY MESSAGE 2...Hazardous marine conditions expected tonight into Sunday.

See the Marine section below for details.

KEY MESSAGE 3: Frost possible Saturday night away from the coast.

Surface high pressure will build in from the north Saturday night leading to fairly light winds and minimal sky cover. These are favorable conditions for radiational cooling, but not ideal as a few knots of NE breeze may persist overnight. At this time, it appears the best chance for decoupling will be west of the I-95 corridor where the pressure gradient will be weakest, however it will be too close for comfort anywhere away from the immediate coast, so consideration should be given to protecting sensitive plants where possible. Overnight lows are expected to range from the mid 30s inland to lower 40s at the coast, but they could easily drop a few degrees lower if the wind does decouple, and in those traditional cold spots, such as Holly Shelter, Green Swamp, etc.

KEY MESSAGE 4: Chance for thunderstorms increases latter half of next week.

Bermuda high pressure will set up next week, and return flow will result in increasing warmth and moisture. PWAT surges to 1.25+" and isolated to scattered showers and thunderstorms should dot the radar in the afternoons and evenings by Wednesday. Coverage should increase a little each day through Friday. A shortwave will lift from the Plains to the Great Lakes Thu-Fri and the associated surface front is expected to remain well NW of the forecast area.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

Generally VFR through 06Z with SW winds that will increase this evening ahead of a strong cold front. Thereafter cigs will lower from the NW and flirt with MVFR. The front will be quite moisture- starved and only brief PROB30s are carried for LBT.

Extended Forecast...MVFR cigs possible through around 12Z Sat before drier air moves in behind a cold front leading to VFR conditions which should then generally prevail through the rest of the period. However, there will be low chances for minor restrictions starting Sun as low-level moisture begins to increase again as high pressure shifts back offshore.

MARINE

Through Saturday...Southwesterly winds will increase this evening, though the cooler SSTs could make that occur slightly slower than forecast as mixing is inhibited slightly. With a strong cold front approaching from the NW tonight the increased pressure gradient will offset this and winds and seas will build quickly. We may see gale- force gusts late tonight into Saturday and the Gale Watch has been raised to a very marginal Gale Warning after collaboration with neighboring offices. The headline goes through 19Z but can likely be lowered early. Depending on whether or not this is the case a SCA may be needed for a few hours thereafter. Spectral buoy plots show that the swell energy has tapered off and that only wind waves remain. This will be the case through the period. In fact the sharp frontal veer and Saturday's gusty N winds will bring two wave groups of less than 5 seconds.

Saturday night through Tuesday...SCA conditions are expected to linger through Saturday night into Sunday before conditions improve by Sunday afternoon. Bermuda high pressure will set up Monday and remain anchored through the week, with generally southerly flow on the order of 10 to 15 kts.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...Red Flag Warning from 8 AM to 8 PM EDT Saturday for SCZ017-023- 024-032-033-039-054>056-058-059. MARINE...Gale Warning from 2 AM to 6 PM EDT Saturday for AMZ250-252-254- 256.