textproduct: NWS Wilmington

WHAT HAS CHANGED

Aviationa discussion updated and heat advisory has been allowed to expire.

KEY MESSAGES

1) Hot weather continues through the first half of this week with additional Heat Advisories possible.

2) Best chances for rain arrive with a strong cold front during mid to late week, including a risk for strong thunderstorms and flash flooding.

3) A period of enhanced winds and seas will exist through midweek as a stronger cold front drops down from the north.

DISCUSSION

KEY MESSAGE 1...Hot weather continues through Wednesday with additional Heat Advisories possible.

The region will remain sandwiched between mid-upper troughing to the north and the closed mid-upper low associated with T.D Two to the south, leaving a weak ridge axis in between. Temperatures in the low- mid troposphere are forecast to hold at similar levels to those observed over the weekend, supporting continued above-normal temperatures and heat indices breaching 100F. The extent of cloudiness and showers/storms will affect whether some areas reach heat indices of 105F, but it appears additional Heat Advisories are possible until the next front comes down mid to late week. Until then, coverage of showers/storms should remain isolated through Wednesday.

KEY MESSAGE 2...Best chances for rain arrive with a strong cold front during mid to late week, including a risk for strong thunderstorms and flash flooding.

The stalled front will continue to lift back to the north leaving the threat of isolated to widely scattered pop-up showers and storms through Wed. Any stronger storms will mainly remain north of the local area as the front lifts north, with the focus of any convection along the sea breeze and any convergence zones that happen to form inland. An isolated strong to damaging wind gust cannot be ruled out if a storm can take advantage of the steep low-level lapse rates combined with a heavy, water-loaded downdraft. Something to watch is the progression of showers and storms to the north, which could send outflow into our northern tier of counties (Pender through Marlboro) and produce areas of heavy showers and storms through late day. Tuesday is looking drier with only isolated convection at the most.

As troughing becomes reinforced over the eastern CONUS during midweek, a stronger cold front is progged to push southward during the Wednesday/Thursday timeframe. While guidance tools have slowed down the frontal progression and suggest Wednesday will be another hot and mostly dry day with isolated pop-up showers and storms, the incoming front is likely to enhance precip coverage into the scattered to numerous realm when it does arrive, which could be over Wednesday night into Thursday.

How far south this front reaches before stalling, and when this occurs, still carries low confidence as guidance tools remain mixed with respect to its position, so this will need to be monitored as shower and storm coverage could be enhanced through the remainder of the week and into the weekend if the front is stalled along the coast as opposed to further offshore over the Gulf Stream.

In addition, this front is expected to bring a risk for isolated thunderstorms with strong to locally damaging wind gusts as wind shear increases to 15-25 kts on Wednesday and Thursday. Perhaps the more notable threat is for flash flooding from heavy storms backbuilding and/or tracking over the same area multiple times. The flash flooding threat will persist if the front stalls along or just inland of the coast.

KEY MESSAGE 3...A period of enhanced winds and seas will exist through midweek as a stronger cold front drops down from the north.

See marine discussion below.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

Storm coverage and strength has been gradually decreasing during the last hour and this trend will continue, likely at a quicker pace. The loss of diurnal instability will allow for more stable conditions to develop across the area. Winds will remain sufficient overnight to prevent fog development and limited boundary layer moisture will prevent stratus. VFR will dominate once the few lingering evening showers come to an end in the next hour or so.any widespread

Scattered afternoon and evening storms will be possible again on Tuesday, but coverage will once again be limited by an overall unfavorable environment. Brief IFR/MVFR will be possible with any storms which will be possible at any terminal. Strong southwest winds will develop with potential for gusts around 30 kt along the coast by midday and in excess of 20 kt inland in the afternoon.

Extended Forecast...Potential for MVFR/IFR from storms will gradually increase beginning Wednesday and remain possible through Saturday, mainly in the afternoon and evening.

MARINE

Monday night through Saturday...Steady south to southwest winds are expected through midweek with daily enhancements nearshore due to the sea breeze. An approaching cold front will help tighten the pressure gradient from Tuesday afternoon into Wednesday night, resulting in the issuance of a Small Craft Advisory with winds and seas firmly above criteria. Winds diminish overnight Wednesday into Thursday as a cold front drifts in from the north and stalls near or over the waters, resulting in low confidence regarding the wind direction on Friday pending the location of the front.

Seas down around 2 to 4 ft will rise to 4 to 6 ft by late Tuesday, remaining through late Wednesday. Seas will diminish to 2 to 4 ft through Thursday as winds weaken. Marine conditions should remain below any thresholds with lower winds and seas as cold front remains in vicinity.

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...Small Craft Advisory from 11 AM Tuesday to 10 PM EDT Wednesday for AMZ250-252-254-256.