textproduct: NWS Wilmington

WHAT HAS CHANGED

All sections have been updated with no significant changes to the previous forecast. A Severe Thunderstorm Watch has recently been issued for all of SE NC and NE SC, with the main hazard being damaging wind gusts of 58+ mph.

KEY MESSAGES

1) Heat Advisory for mainly coastal counties with the expectation for showers, storms, and/or cloud cover to reduce temperatures by mid-late afternoon.

2) Isolated severe storms and flash flooding possible today through tonight.

3) Near-normal temperatures expected in the long-term with low rain chances for Sunday/Monday before increasing midweek.

DISCUSSION

KEY MESSAGE 1...Dangerous heat continues today closer to the coast.

Although increasing showers/storms/clouds will keep temperatures and heat indices lower in some spots we will keep the Heat Advisory up for at least a few more hours for heat indices generally in the 105- 109 degree range.

KEY MESSAGE 2...Isolated severe storms and flash flooding possible into tonight, with a low risk for flash flooding continuing on Saturday.

A trough in the jet stream and attendant cold front progressing eastward into the Carolinas will yield scattered to numerous showers and thunderstorms into this evening. A Severe Thunderstorm Watch has recently been issued for mainly the risk of damaging wind gusts, although large hail and a tornado can't completely be ruled out. Moderate to strong instability, steep low-level lapse rates, and anomalously high precipitable water values (~2"+) will all contributing to a wet microburst threat. Frequent lightning and very heavy rainfall are also expected with isolated flash flooding possible, especially inland from the coast where storms move over the same areas for an extended period. A low flood risk will continue into Saturday, mainly near/east of I-95 and in areas that pick up a good deal of rain today/tonight.

KEY MESSAGE 3...Near-normal temperatures expected starting this weekend with low rain chances Sunday/Monday before increasing mid week.

Scattered showers and thunderstorms will remain possible through Saturday night as a cold front stalls just west of or over the forecast area while impulses aloft continue to move through the broader trough in the jet stream. A period of mostly dry weather appears likely on Sunday and Monday as the front is shoved offshore. However, as the flow aloft becomes westerly to northwesterly around midweek, additional impulses and waves of low pressure are poised to bring periods of showers and thunderstorms from Tuesday onward, with the best chances for more widespread rain currently focused on Thursday. Of course, given this is multiple days away, the chances for rain will likely fluctuate in the coming days as smaller-scale details are worked out.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

18Z Fri thru 18Z Sat: A stalling front will bring scattered to numerous showers/storms across the area into this eve, with some rain lingering overnight into Sat, mainly near the coast. A severe wind gust (~50 kts) and hail up to quarter size is possible in the strongest storms thru early to mid evening. Also, expect a low to moderate risk for cig/vsby restrictions late tonight into Sat morning.

18Z Sat thru Tue: Mostly VFR expected outside low to moderate risk for cig/vsby restrictions late Sat night/early Sun, mainly inland at KLBT/KFLO. Scattered to numerous showers/thunderstorms will continue Saturday afternoon/evening, especially near the coast. Low risk for restrictions from showers/storms Sun/Mon with a bit better risk Tue, especially near the coast.

MARINE

Today through Tuesday... Expect generally south to southwest winds to prevail through the period as an approaching cold front stalls near the coast. No headlines are expected as winds peak around 15-20 kts over Saturday night and wave heights stay around 3 ft or less within 20 nmi and up to 4 ft in the 20-60 nmi zones, highest this weekend.

The biggest marine impact will likely be from increasing coverage of showers and thunderstorms beginning this evening and continuing through the weekend as a front stalls near the coast. There will likely be several rounds of storms, accompanied by reduced visibility and possible gusty winds.

ILM WATCHES/WARNINGS/ADVISORIES

NC...Heat Advisory until 8 PM EDT this evening for NCZ099-105>110. SC...Heat Advisory until 8 PM EDT this evening for SCZ054>056-058- 059. MARINE...None.