textproduct: NWS Wilmington

WHAT HAS CHANGED

A Coastal Flood Advisory has been issued for the lower Cape Fear River during high tide this evening.

KEY MESSAGES

1) Rain Friday night into Saturday could put a small dent in our drought.

DISCUSSION

.KEY MESSAGE 1: Rain Friday night into Saturday could put a small dent in our drought.

A wave of low pressure along lingering front to the south to southeast will help to produce decent rainfall for Saturday. Late Friday into Saturday a southern branch feature lifts out of Texas and phases into the northern branch above the MS Valley. This will lead to the development of low pressure on the Gulf Coast boundary that then runs close to the FL/GA border before turning up the Southeast Coast. This is one of the better situations for rain in the Carolinas for the time of year as the rain will be widespread and stratiform at a time when precip is climatologically becoming strictly spotty and convective.

Around midday Saturday when the offshore low makes its closest approach the baroclinicity further up in the boundary layer tightens up, strengthening the ongoing isentropic upglide, this ascent then further benefiting from mid level PVA and weak height falls. Rainfall coverage and intensity will pick up leading to this point after which all players surface and aloft move offshore. Only a broad-brush QPF is possible at this time but the 1.0" area average seems a good one.

As mentioned previously instability is lacking even aloft so thunder appears to remain out of the realm of possibility. Another benefit of stratiform rain vs convective is that the latter typically falls with a higher intensity and the initial amounts are lost to runoff. Slower rainfall rates foster better absorption and retention to the water table.

AVIATION /00Z THURSDAY THROUGH MONDAY/

VFR and light SW winds ahead of an approaching cold front to start the 00Z TAF period. Scattered showers are expected overnight over northern areas with the fropa but cigs should stay VFR. Another batch of light rain is expected to move in from the SW Thursday morning, accompanied by moderate chances for MVFR cigs and low chances for IFR mainly over southern areas. VFR should then return by afternoon and persist through the end of the TAF period.

Extended Forecast... A warm front will lift northward late Friday into Saturday with showers bringing restrictions through Saturday. VFR returns on Sunday into early next week.

MARINE

Through Thursday...Southwesterly winds are expected to increase tonight as a cold front works its way through the Carolinas. Gusts up to 20 knots will be possible after midnight with seas increasing to 2-4 feet in the nearshore waters, 4-5 in the 20-60 offshore waters. Improvement is expected behind the cold front on Thursday with light offshore winds. Poor pressure gradients behind the front should keep winds light through Thursday evening. Seas improve in light winds on Thursday, up to 1-2 feet, 2-4 feet in the 20-60 waters.

Thursday night through Sunday...Northerly winds behind cold front will start veering into Friday as high pressure to the north migrates eastward over NC, sliding off of the DelMarva Coast later on Friday. Conditions deteriorate Friday night into Saturday as a wave of low pressure develops along lingering front to the south and moves up the SE coast. Winds will increase up to 15 to 20 kts through late Sat as they back to the N then NW as low passes by, then lifts off to the NE and intensifies. This should push seas into Small Craft Advisory thresholds, mainly beyond 20 nm, Sat through early Sun. Intermittent heavier rainfall could lead to visibility restrictions. The low moving up the coast will disrupt the SE swell that had been coming into the area and the overall dominant wave period will grow a bit shorter.

ILM WATCHES/WARNINGS/ADVISORIES

NC...Coastal Flood Advisory until 10 PM EDT this evening for NCZ107. SC...None. MARINE...None.