textproduct: NWS Wilmington

SYNOPSIS

Well above-normal temperatures will continue with an occasional shower possible through Wednesday. Arctic air will follow a strong cold front Wednesday night leaving well below normal temperatures and much drier air Thanksgiving Day through Saturday. A warming trend will begin Sunday as high pressure moves off the coast with increasing rain chances into next week.

UPDATE

Only minor changes made to previous forecast with area of light showers currently moving across coastal SE NC. 0z aviation discussion.

NEAR TERM /THROUGH WEDNESDAY/

Coastal trough has moved ashore and along with it a SE wind and some impressive temperature jumps along the coast. In the resulting WAA a small patch of rain is moving up the SC coast and most guidance has increased the likelihood that this area of disturbed weather will hold together up our coastal areas. Rain chances have been increased to about 40 percent as previous thinking that most of the rainfall will not be measurable still holds. There is uncertainty regarding the impressive line of showers now crossing western SC. At this time blended guidance and CAMs show it weaken, turn north and miss our western zones.

As the trough erodes by tonight the entire area will be in a healthy warm sector, the strength of which indicated by nighttime lows that are almost as warm as our climatological highs. In this warm sector tomorrow, a sheared line of vorticity will try to introduce a line of showers from the west but guidance isn't too excited about measurable precip and given how dry soundings remain this seems plausible. With such a warm start any given location's chance at hitting 80 may hinge upon the extent of cloud cover.

SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/

Huge change in air mass expected with a 20 degree drop in high temps by Thurs. An arctic cold front will be making its way through the eastern Carolinas with strong CAA through Wed night. A fairly broad trough will extend down from deep mid to upper low in the Great Lakes, helping to drive this strong cold front through and provide plenty of dry and cold advection into the Carolinas for Thanksgiving day through Saturday. The 850 temps up near 13c late Wed will plummet down below 0 by Thurs aftn and down to -7c by Fri. CAA will bring lows down into the 40s by Thurs morning and will only return into the mid 50s for highs on Thanksgiving Day. A reinforcing shot of cold air will come into Thurs night with as the mid to upper trough axis clears the coast. Expect lows near or below freezing Thurs night. High temps on Fri may not even reach 50 degrees after a very cold morning and continued CAA. With such a dry air mass, there will be plenty of sunshine but also some gusty winds in the afternoon.

The best CAA will come to an end into Fri night, but the center of the high will draw near with better radiational cooling. This will lead to another chilly night with widespread low temps in the 20s. After another chilly start, temps will fight to get to 50 under bright end of November sunshine.

LONG TERM /FRIDAY THROUGH TUESDAY/

A slow modification of the air mass will take place over the latter half of the weekend as high pressure shifts eastward making it off the coast to the north of our area. This will lead to an onshore flow developing at the sfc. The flow aloft will shift to the SW to W. This onshore moister return flow will help to begin a slow recovery of dewpoints from the teen on previous couple of days into the 40s and 50s by late Sun into Mon. Pcp water values will be back up to an inch by Sun aftn, from less than a quarter of inch previous days. A more typical pattern will develop Sun into Mon with high pressure wedge inland and coastal trough developing along the coast. This should lead to increasing clouds and chance of pcp through early next week. Temps will be affected by clouds and pcp but overall expect a return into the 60s Sun through Tues.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

An area of light rain is currently moving across southeast NC, and will exit the area in a couple of hours. Patchy fog is forecasted to develop across the area for a few hours behind the rain, until 6-7z, before winds increase towards morning. MVFR cigs may also impact terminals into overnight hours, especially at coastal terminals, before clearing out during pre-dawn hours. Predominantly VFR Wednesday morning through end of TAF period, with exception of brief flight restrictions with a line of weakening showers moving across from the west in the afternoon. There may be a window of LLWS between 8z and 13z at inland terminals as LLJ of 35-40 kt SW winds moves across, with increased surface winds precluding LLWS at coastal terminals by the time LLJ arrives. Surface winds predominantly southwesterly through TAF period, with gusts around 20 kts Wednesday afternoon.

Extended Forecast...VFR returns late Wednesday and continues through Sunday.

MARINE

Through Wednesday...The area will be in a strong warm sector through the period, the parent low all the way up into the Great Lakes. The remainder of today into tonight will be breezy, but then tomorrow the approach of the front squeezes the gradient. Advisory- worthy 25-30kt gusts should become frequent enough for headlines (already hoisted last night) for NC waters.

Wednesday night through Saturday...Arctic air will make its way over the waters behind a strong cold front Wed night into Thurs. Gusty SW to W winds will shift around to the north into Thurs. A secondary surge of cold air should kick winds up again late Thurs into Fri. Overall, expect the best surge in winds and seas leading up to the front with a downward trend into Thurs, but possibly another bump up with secondary surge Thurs night. Overall, winds and seas should remain sub-SCA, but may get close for winds at times Wed night through Thurs night.

High pressure moves closer Fri night into Sat before shifting off the NC/VA coast late Sat. An onshore return flow will develop with winds coming around from the N to NE through Sat.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...Small Craft Advisory from 7 AM to 7 PM EST Wednesday for AMZ250-252.