textproduct: NWS Wilmington

WHAT HAS CHANGED

Updated aviation discussion for 00Z TAFs.

KEY MESSAGES

1) Very small but non-zero threat for some gusty storms this evening.

2) A short period of dry weather is expected Friday before rain chances return Saturday through Monday.

DISCUSSION

KEY MESSAGE 1: Very small but non-zero threat for some gusty storms this evening.

The area is currently transitioning from the isentropic upglide rains of this morning/midday. There will be a lull in rainfall in the very near term in both coverage and intensity. The next forecast challenge regards the possible return of both with the cold front this evening as it approaches from the NW. The main problem with this boundary lighting up much with activity is the fact that highs and thus instability fell short of the mark today. Even cranking up some of the WoFS wind gust parameters gives little to no coverage, and the main one being near FLO in the next hour or two, which seems unlikely.

KEY MESSAGE 2: A short period of dry weather is expected Friday before rain chances return Saturday through Monday.

Dry weather is expected Friday as a flat upper ridge supports weak surface high pressure that drifts eastward across the Carolinas during the afternoon. Precipitable water should fall to 0.5 inch inland and around 0.75 inch at the coast.

The high will push offshore Friday night. Gulf return flow arriving early Saturday morning should lead to scattered to numerous coverage of showers and isolated thunderstorms during the day Saturday, persisting throughout the rest of the weekend. With models showing relatively high precipitable water values around 1.5 to 1.7 inches continuing through Sunday night along with a steady train of subtle southerly stream upper impulses, chances of rain will always be present through the weekend. The current forecast is similar to the previous one, with the exception being slightly higher rain chances on Saturday towards the coast due to better agreement amongst the models at that timeframe. Rain chances are also a bit higher now on Monday (70-80% over much of the area) as the final shortwave pivots through the area before dry and cooler air moves in for Tuesday.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

Moderate to high confidence for the 00Z TAFs. Terminals starting out VFR but some showers and possibly a few thunderstorms will impact the area this evening as a cold front moves through the area. Any stronger storm could bring higher winds than currently forecast. Otherwise, main impact will be MVFR/IFR cigs for a few hours. May see some fog develop late, mainly inland at KLBT/KFLO, but confidence remains too low to mention.

Extended Forecast... Continued improvement to VFR expected Friday morning, remaining that way through at least Saturday morning. May have some possible restrictions Saturday, due to increased rain chances at the coast. More widespread unsettled weather expected Sunday and Monday.

MARINE

Through Friday... Pre-frontal flow regime has remained sub- advisory and should continue to do so ahead of the front. FROPA will bring veering and decreasing winds. Seas will abate not only from the decrease in wind speed but also due to the turn to offshore...this effect most pronounced and quickest out to 20 nm vs 20-26nm. Wave period will remain on the shorter side of the spectrum in the absence of swell, wave direction gradually changing from S to N, lagging the windshift as always.

Friday night through Tuesday... Sfc high pressure slides offshore Friday night before southerly flow redevelops for the weekend into early next week with the high staying offshore. Sustained winds up to 10-15 kt Saturday through Monday will increase up to around 20 kt Monday night following the next cold fropa. Confidence is low to moderate on the need for a SCA over the 0-20 NM coastal waters as the most likely scenario right now is for only occasional gusts to 25 kt with weak-moderate CAA, and seas up to 4-5 ft. Gusts likely top out around 25-30 kt over the 20-60 NM waters.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...None.