textproduct: NWS Wilmington

WHAT HAS CHANGED

Aviation discussion updated for the 12Z TAFs.

KEY MESSAGES

1) Expect a mild day with a period or two of light to moderate rain before cooler and drier air filters in tonight.

2) A storm system will likely bring some very beneficial rain Saturday night through early next week.

DISCUSSION

KEY MESSAGE 1: Expect a mild day with a period or two of light to moderate rain before cooler and drier air filters in tonight.

A cold front will gradually push through the region from the northwest today with a weak disturbance aloft helping to generate a period or two of light to moderate rain along and ahead of the boundary, starting mainly after 7am and ending from north to south this afternoon. With very little instability aloft and generally weak forcing driving this precip, rainfall amounts are expected to be mostly light, ranging from a few hundredths to a few tenths of an inch over about 6 hours. Although guidance tools vary considerably in where the most precip falls, it appears one or two WNW to ESE streaks of peak totals will be realized. Some areas may also see convectively-enhanced showers accompany the frontal passage, leading to local maxes streaking from north to south, mainly in our SC zones. Otherwise, mild temps in the 60s, dewpoints in the 50s, and gusty southwest to WSW winds are anticipated today, a marked departure from the weather of the last few weeks. However, as the cold front settles southeastward this afternoon, expect temperatures and dewpoints to tumble behind it as steady north winds take over and bring temps into the 30s and dewpoints into the 20s.

KEY MESSAGE 2...A storm system will likely bring some very beneficial rain Saturday night through early next week.

A storm system is expected to move through the region later in the weekend through early next week. There is still some uncertainty regarding the evolution/timing of this system so confidence is low to moderate regarding forecast details. However, there is a moderate risk for greater than 1" of rain and even a low risk for greater than 2" (mainly near the coast), which would certainly be welcome given the ongoing moderate to severe drought conditions across SE NC and NE SC. Could even see a few generally weak thunderstorms late Sun and/or Sun night when the low passes through, especially near the coast. Severe storms are highly unlikely though due to limited instability.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

Breezy WSW winds aloft will maintain LLWS concerns into this morning until those winds can mix down and reduce the shear, which is expected by 14Z. A cold front and weak disturbance aloft will bring periods of rain to the terminals today with about a 3-6hr window of MVFR cigs anticipated. Guidance tools have recently backed off on the duration of MVFR cigs, and cigs in these weak forcing scenarios tend to feature more VFR than forecast, so it is possible that even the current forecast is too pessimistic on the duration of MVFR cigs. Rainfall intensity should generally stay light enough to preclude MVFR vis restrictions, but brief reductions to 4 or 5SM cannot be ruled out if a moderate shower passes directly over a terminal, which has the best chance of occurring with the frontal passage itself over the SC terminals. Otherwise, expect VFR to return from north to south this afternoon into early this evening as the cold front settles southeastward. Breezy WSW winds will initially turn northwest, then settle on northerly tonight as dry air filters in, keeping VFR in the forecast through the end of the TAF period.

Extended Forecast...VFR conditions expected across all TAF sites through Friday as cold high pressure dominates. Flight restrictions are expected to develop across the area Saturday into Sunday as low pressure tracks east across the Deep South and Southeast US.

MARINE

Through Tonight... Breezy WSW winds will dominate today ahead of a cold front with periods of rain crossing the waters during the day. The front will settle southeastward this afternoon into this evening, turning winds northwesterly at first, then becoming northerly overnight. Marginal SCA conditions in outer portions of the waters will continue until the front moves through and turns winds offshore. Winds around 15-20 kts with gusts to 25 kts and seas mainly around 3-5 ft peak around midday today before temporarily subsiding with passage of the front. Offshore flow increases overnight with north winds reaching 15-20 kts mainly after midnight and seas holding around 2-4 ft. Seas will see a primary contribution from wind waves with a decaying contribution from the 12-13 sec ENE swell of 1-2 ft this morning, becoming 1 ft this afternoon.

Thursday through Sunday night...High pressure to the north will shift offshore this weekend with a storm system expected to move through the area early next week. There is a moderate to high risk for Small Craft Advisory conditions due to elevated winds/seas starting Sun afternoon, although forecast details are still a bit uncertain due to uncertainty regarding the storm track/timing/strength. There is even a low risk for gale force gusts.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...Small Craft Advisory until 1 PM EST this afternoon for AMZ250- 252-254-256.