textproduct: NWS Wilmington

SYNOPSIS

An arctic front, moving through tonight, will bring well below normal temperatures and much drier air Thanksgiving Day through Saturday. High pressure will move off the coast by Sunday as a cold front approaches. Rain chances increase into next week as a wave of low pressure moves up the Southeast coast.

UPDATE

A wind shift this evening will usher in cooler air after midnight. Current forecast on track. Winds will remain relatively light, and the marginal SCA north of Little River Inlet will be allowed to expire at 7 PM.

NEAR TERM /THROUGH THURSDAY/

A two-staged cold front will push through this evening. The lead boundary will have some baroclinicity but is mostly a wind shift, especially compared to the second. And although the second front will start to usher in lower temperatures and dewpoints, the mega- cold advection is a bit delayed into Thursday when 850mb flow finally goes north of west. The CAA partially offset by the return of sunshine will flatten the daytime temperature curve, which is expected to peak in the mid to upper 50s. Such highs represent out minimum averages that occur in early January.

SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/

Deep low over the Great Lakes and high strung out from the Upper Plains to the lower Mississippi Valley will continue to produce a deep flow of very cold and dry air into the Carolinas Thurs night into Fri. As the trough axis aloft clears the coast, a reinforcing shot of cold and dry air will reach the area Thurs night into Fri. Overnight lows will be below freezing most places inland of the direct coast Thurs night. High temps on Fri will not even reach 50 degrees across most of the area in continued CAA.

Looks like 850 temps bottom out Fri aftn below -7c before rebounding Fri night into Sat as the mid to upper low lifts off to the northeast with height rises. A more zonal flow aloft will set up Fri night into the weekend, but the position of the high over the western Carolinas should provide better radiational cooling. Therefore expect the coldest night, with temps in the low to mid 20s and possibly lower across traditionally colder spots.

Overall, a very cold and dry period. As the driest air reaches the area on Fri in gusty NW winds and dewpoints bottom out in the teens Fri aftn, could see some Fire weather concerns.

LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/

Although the air mass will begin to modify over the latter half of the weekend, overnight lows will continue below normal, with most places in the low to mid 30s Sat night. High pressure will shift eastward making it off the coast to the north of our area Sat night into Sun as next system approaches from the west. A wedge pattern may set up with high pressure continuing to extend back into the inland Carolinas and coastal trough developing. This should lead to weak isentropic lift producing possible pcp inland, mainly west of local area. This pattern will break quickly as cold front approaches by Sun aftn. Therefore expect warming on Sun in southerly return flow by aftn but shallow cool air should make it south by Mon as front drops south. The shallow cool air will be overrun by warm moister air aloft as deepening mid to upper trough to the west provides increasing SW flow aloft. A wave of low pressure should help provide decent QPF into Tues, before lifting north and out of the area by midweek. Temps will be relatively warmer, but mainly near or below normal after a slightly warmer Sunday.

AVIATION /00Z THURSDAY THROUGH MONDAY/

VFR. A weak surface trough was near the coast as of 22Z, but will only serve to bring a slightly more westerly component to the relatively light winds. A second surface trough/front will move quickly from the NC foothills to the coast and move offshore around midnight, bringing a more significant wind shift, though winds will remain light.

Extended Forecast...Brief sub-VFR possible early next week.

MARINE

Through Thursday...SCA having a bit of difficulty verifying but with the impending frontal wind shift there could be some better alignment in the vertical for an increase in gustiness this afternoon. Otherwise the remainder of the period will feature breezy but sub-advisory NW winds in an increasingly strong CAA regime. A minor SE swell is noted in wave bulletins but the 3-4 second wind chop will be the dominant wave.

Thursday night through Monday...A reinforcing shot of cold and dry air will come Thurs night into Fri with some gusts up to SCA thresholds, but overall, should remain sub-SCA. High pressure over the Appalachians early Sat will shift off the NC/VA border by Sat night into Sun with winds shifting around from more offshore Thurs night into Fri to onshore Sat into Sun. Seas should remain 2 to 3 ft most of the period. A southerly return flow should set up briefly on Sun ahead of a cold front, before coming back around to the north as front moves south by Mon. Then a wave of low pressure could move up the Southeast Coast late Mon into Tues with increasing winds and seas.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...Small Craft Advisory until 7 PM EST this evening for AMZ250- 252.