textproduct: NWS Wilmington

WHAT HAS CHANGED

No significant forecast changes.

KEY MESSAGES

1) Showers and storms capable of producing locally heavy rainfall and isolated flooding through this evening.

2) Strong southerly winds and hazardous marine conditions expected to develop Sunday into Monday.

DISCUSSION

KEY MESSAGE 1...Showers and storms capable of producing locally heavy rainfall and isolated flooding through this evening.

A weak meso-low along a stalled frontal zone and attendant MCV responsible for a cluster of heavy rain showers that produced 1 to 2 inches of rain across portions of Brunswick, New Hanover and Pender counties earlier this morning has moved north and east of the area.

However, daytime heating and moderate destabilization within the moist airmass, combined with weak synoptic height falls associated with the upper trough building into the region and additional upper impulses traversing the region, should support the re-development of scattered showers and thunderstorms through this evening. Showers and thunderstorms will remain possible near the immediate coast and offshore tonight as impulses aloft interact with instability over the very warm ocean.

Locally heavy rain and isolated flash flooding will remain possible through this evening, with HREF and REFS highlighting coastal counties/zones as having the greatest potential for localized 2-4" rainfall totals. Modest lapse rates and shear should limit the overall severe threat, though an isolated wet microburst cannot be ruled out.

KEY MESSAGE 2... A reprieve from the extreme heat with shower and storm chances returning mid to late next week.

An upper air pattern featuring a strong upper-high anchored over the Southwest and mean troughing over the east-central U.S. will prevail through the period. This pattern will will bring a welcomed reprieve from the recent extreme heat, with temperatures returning more to seasonable levels along with and lower BL dewpoints and humidity.

Noticeably drier air and lower PWATs, potentially falling into the lowest 2 to 10 percentile of climatology will advect into the area Sunday. Despite a lingering weak boundary and weak disturbances swinging through the area, the dry air should limit rain chances to mainly widely scattered showers and storms, focused near the immediate coast Sunday and Monday.

Moisture and instability will gradually return to more typical levels Tuesday onward, yielding chances of mainly diurnal showers and storms through the remainder of the period. Storm coverage could increase to to likely or numerous levels Friday and Saturday as the next cold front approaches the area.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

Lingering sub-VFR ceilings should lift to VFR between 18 to 20z. Isolated to scattered showers and storms are expected to re-develop across the area this afternoon and into the evening, with greatest coverage expected along the coastal terminals. Showers and storms will remain possible near the immediate coast and offshore tonight as impulses aloft continue to interact with instability over the very warm ocean.

The main aviation concern with this package is the potential for areas of fog and stratus during the predawn hours Sunday morning. Latest hi-res guidance suggests inland TAF sites (KFLO and KLBT) have the greatest potential for IFR to MVFR restrictions between 09z to 12z Sunday. Any sub-VFR restrictions that develop should lift/improve rapidly between 12 to 14z with isolated to scattered convection expected Sunday afternoon and evening, mainly along the immediate coast.

A weak surface boundary bisecting the area should result in light winds through the period, with inland TAF sites becoming predominately west-northwesterly Sunday.

Extended Forecast... Rain chances will be relatively low Monday, followed by a return of scattered diurnal showers and storms Tuesday through Thursday as humidity and moisture increases. Periods of early morning fog and low stratus will also be possible.

MARINE

Today through Thursday...Marine conditions are expected to remain below Small Craft Advisory criteria through the period.

Expect generally south to southwest winds to prevail through the period as a weak front stalls near the coast. Winds are expected to 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 scattered to numerous showers and thunderstorms over the waters 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...None. SC...None. MARINE...None.