textproduct: NWS Wilmington

WHAT HAS CHANGED

QPF for the Sat afternoon thru Monday morning associated with the approach and passage of a cold front has been revised.

Updated aviation discussion for the 12Z TAFs.

KEY MESSAGES

1) Just 1 more day of above normal temperatures, low daytime relative humidity, and with limited rain chances through early Sat evening. This will all combine to continue the ongoing drought and fire weather concerns.

2) Rain Saturday night into Sunday associated with a cold front will not bring appreciable drought relief.

DISCUSSION

KEY MESSAGE 1...Just 1 more day of above normal temperatures, low daytime relative humidity, and with limited rain chances through early Sat evening. This will all combine to continue the ongoing fire weather concerns.

Mid to upper 80s, possibly an isolated 90 degree reading, will dominate Saturdays highs compared to normal highs generally running in the upper 70s. This mornings lows and Sunday morning lows will run in the 60s, with normal lows being in the low to mid 50s. This afternoons RHS will drop into the 25 to 35 percent range away from the coast. Combined with active SSW-SW winds gusting 15 to 20 mph and the ongoing and widespread severe drought, a fire danger statement is in effect for the Southeast NC region for the increased risk for wildfires. Of note, a State-Wide burn ban remains in effect for both NC and SC until further notice. Thunderstorm activity will be isolated at best during this aftn, mainly in the vicinity of the sea breeze. The better chance for more widespread convection will occur later this evening into Sun where it will partially alleviate the immediate fire danger the next day, Sun.

KEY MESSAGE 2...Rain Saturday night into Sunday associated with a cold front will not bring appreciable drought relief.

Weak low pressure ahead of an upper shortwave will bring rain to the area Saturday night into early Sunday. There will be a window between overnight activity and approaching cold front from the north where instability will develop Sunday, especially across coastal counties, and will likely pop-up storms during the day into afternoon hours before cold front moves across late in the day ushering in cooler and drier air. All in all though, total rainfall won't be enough for drought relief. Expected rainfall ranges from 0.1" to isolated areas of 0.5+ inches, with coastal Cape Fear having the best chance of seeing the higher rainfall totals through Sunday night. With our area being 5-7 inches below normal in year to date rainfall, drought conditions will persist until we get more appreciable rainfall, and more frequent.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/

High confidence in VFR prevailing through at least late this afternoon. The 15-25kt SW LLJ will keep sfc winds active enough through this morning, ultimately preventing any widespread ground fog development. Today a repeat of Fri, more or less, with thin cirrus with diurnally driven cu mainly along and inland of the sea breeze. Isolated showers and perhaps a thunderstorm should form once again in the vicinity of the sea breeze but too low confidence to place in the TAFS. However, for this evening, convective activity ahead of the approaching cold front should begin affecting the inland terminals initially then reaching the coastal terminals by late this evening or around midnight. Have only included PROB30 groups to highlight. But then do have prevailing light showers and fog after midnight thru daybreak at all terminals in response to the front either pushing thru or stalling nearly overhead. SW around 10 kt to dominate except with the sea breeze from midday thru this evening where winds will back to the S-SSW 10-15 kt with few/occasional g20 kt after its passage as it progresses inland. Tonight look for winds to veer to the NW then N-NE as the cold front pushes overhead. MVFR conditions expected to develop across all terminals during the pre-dawn Sun hrs, progressing from inland to the coast.

Extended Forecast...Convection associated with the cold front could bring periodic MVFR conditions Sat night through Sun. Flight restrictions from stratus/fog are possible Sun night and Mon night.

MARINE

Through Tonight... A somewhat tightened sfc pg will exist between the center of the retreating offshore high and the approaching cold front from the NC-SC mainland. Will see the nocturnal SW LLJ fade after daybreak but the remaining gradient should be enough for SW winds 10-15 kt few gusts 20 kt especially 20-60nm out. Nearshore, within 10 nm of the coast, winds back to the S to SSW winds and increase to around 15 kt with more frequent gusts to 20 kt in the aftn/evening due to the formation and inland progression of the sea breeze. Some timing differences of the models with respect to the CFP, so for now will position the cold front right along the immediate coast come daybreak Sun. Look for an increase in convection coverage across the waters, both coastal and offshore waters later Sat evening and especially overnight thru daybreak Sun. Seas will be governed by locally produced wind chop at 5 or less second periods. An underlying 1 foot E-ESE 9+ second period swell will continue.

Sunday through Wednesday Night... A cold front will cross the waters on Sunday bringing veering from SW all the way to N as a cool season-looking wedge of high pressure noses in from the north. Winds increase a category with FROPA but no headlines are anticipated. The veer may also kill off what weak swell energy had been in place with only two shorter period wind waves in the forecast by Monday. The wedge washes out by Tuesday allowing for a return of southerly flow that will likely be capped at just 10kt for the remainder of the period.

ILM WATCHES/WARNINGS/ADVISORIES

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