textproduct: NWS Wilmington

WHAT HAS CHANGED

All sections have been updated with no significant changes to the previous forecast.

KEY MESSAGES

1) Dangerous heat possibly continues into Friday.

2) Isolated severe storms and flash flooding possible Friday.

DISCUSSION

KEY MESSAGE 1...Dangerous heat possibly continues into Friday.

Above normal temperatures will continue through Friday, although slightly cooler temps should prevail Friday given the increased cloud/rain coverage. Despite cooler temps the humidity will remain high and thus heat indices should peak close to 105 degrees for at least a part of the area (especially near the coast) before showers and thunderstorms develop. However, due to the uncertainty and marginal nature to begin with we opted to hold off on issuing a Heat Advisory at this time.

KEY MESSAGE 2...Isolated severe storms and flash flooding possible Friday.

A trough in the jet stream and attendant cold front progressing eastward into the Carolinas on Friday should yield scattered to numerous showers and thunderstorms, with a very low (1 out of 5) risk for strong to severe wind gusts and/or large hail. In addition, a very moist air mass combined with fairly weak storm motions (mainly 20 kt or less) will lead to a slight (at least 15%) risk for excessive rain leading to flash flooding, mainly near/west of I-95. Inland areas should have the highest coverage of storms as the sea breeze moves inland, although coastal areas should get in on the rain later in the day as showers/storms drift back east toward the coast.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

18Z Thu thru 18Z Fri: High confidence in prevailing VFR conditions. Very low risk for restrictions from showers/storms mainly thru this eve and again Fri (especially after 15Z) as well as late night/early morning stratus/fog (mainly inland at KFLO/KLBT).

18Z Fri thru Mon: Brief MVFR/IFR conditions are possible in areas of ground fog or low stratus Sat night/Sun morning.

Chances for thunderstorms and related MVFR to LIFR vis restrictions will become moderate to high Friday afternoon and again Saturday afternoon as a cold front approaches the eastern Carolinas. Scattered thunderstorms may continue through Sunday and Monday, mainly in the afternoons near the coast affecting KILM, KCRE, and KMYR.

MARINE

Tonight through Monday...Light south winds today will shift southwest to west tonight as a cold front approaches from the northwest. Expect generally south to southwest winds to then prevail the rest of the period as the front stalls near the coast and just inland. No headlines expected as significant wave heights stay about 3 ft or less within 20 nm and up to 4 ft in the 20-60 nm zones, highest this weekend.

The biggest marine impact will likely be from increasing coverage of showers and thunderstorms beginning Friday 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 NCZ087-096-099- 105>110. SC...Heat Advisory until 8 PM EDT this evening for SCZ017-023-024- 032-033-039-054>056-058-059. MARINE...None.