textproduct: NWS Wilmington

WHAT HAS CHANGED

Updated key messages for the possibility of a few strong to severe thunderstorms Sunday afternoon/evening. Also, included a new message for the low-potential tropical cyclone formation off the southeast U.S. coast next week and updated the aviation section for the 18Z TAFs.

KEY MESSAGES

1) A few strong to severe thunderstorms possible, especially Sunday afternoon and evening.

2) Potential tropical cyclone development of the southeast U.S. coast during the upcoming week.

3) Heat and humidity will continue Sunday, and especially toward the end of the upcoming week.

DISCUSSION

KEY MESSAGE 1...A few strong to severe thunderstorms possible, especially Sunday afternoon and evening.

While we may have to contend with a few strong to severe thunderstorms this afternoon and evening the focus will shift to a MCV expected to move across NC during Sunday. There should be sufficient instability coincident with ample moisture to create scattered showers and thunderstorms. A MCV, weak front/trough, and the sea breeze will provide the lift. Currently, SPC highlights the entire forecast area in a Marginal Risk. The primary severe weather type would be damaging wind gusts.

KEY MESSAGE 2...Area of potential tropical cyclone development of the southeast U.S. coast during the upcoming week.

An area of low pressure is expected to form off the southeast United States coast during the upcoming week and it could attain tropical characteristics as it drifts toward the west through mid-week. NHC is highlighting a 20% chance formation in the Graphical Tropical Weather Outlook, and uncertainty with its development and any subsequent impacts is high at this time.

KEY MESSAGE 3...Heat and humidity will continue Sunday, and especially toward the end of the upcoming week.

Heat indices will approach Heat Advisory thresholds during Sunday as highs in the mid 90s coupled with the humidity will make conditions uncomfortable. It looks like there will be some reprieve from the heat Monday and Tuesday then the heat and humidity will return Wednesday, but more-so Thursday through Saturday.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

18Z Sat through 18Z Sun: Water vapor shows a ribbon of higher moisture from near the coast to the offshore waters, with a drier swath across inland areas early this afternoon. The sea breeze front will likely spark some showers and thunderstorms potentially affecting the coastal terminals this afternoon. Meanwhile a few strong storms in the westerlies could be in the vicinity of KLBT, and to a lesser extent KFLO this evening. The best chances are for terminals north of the area, but a subtle shift to the south would increase chances and KLBT and later downstream at KILM this evening. SSWly winds will be gusty at times along the coast due to the sea breeze and the pressure gradient. Overall, outside of any convection expect VFR conditions.

Extended Forecast...Storms are likely, especially after 18Z Sunday into Sunday evening ahead of a cold front. The front will linger near, or just south of, the area during Monday. However moisture will become limited through the column with only isolated showers or thunderstorms possible Monday. Could also see some stratus develop early Monday morning, but confidence is low at this time. Otherwise, VFR conditions are likely Tuesday through Thursday.

MARINE

SWly flow will prevail across the coastal/offshore waters for the remainder of today through Sunday. The pressure gradient will make it very choppy during this time with seas around 4 ft most areas. Storms are expected to move off the coast by Sunday evening, skewing the wind field at times until a front moves off the coast and shifts offshore. NEly flow will develop in its wake during Monday. NEly flow could be prolonged Monday night into Wednesday given the potential low development off the southeast U.S. coast. This low is being monitored by the National Hurricane Center for potential tropical transition as it drifts toward the west.

ILM WATCHES/WARNINGS/ADVISORIES

NC...Beach Hazards Statement until 8 PM EDT this evening for NCZ106- 108. SC...Beach Hazards Statement until 8 PM EDT this evening for SCZ054- 056. MARINE...None.