textproduct: NWS Wilmington

SYNOPSIS

Dry weather and moderating temperatures are expected the rest of the week. An arctic cold front will arrive on Sunday, followed by the coldest air yet this season. Dangerously cold wind chills and offshore gale force winds are possible late Sunday into Monday morning. The arctic high will move offshore Tuesday, followed by a warming trend for the second half of the week.

NEAR TERM /THROUGH FRIDAY/

Northwest flow aloft will continue through Friday although relaxing a bit in time. Sunny skies and gusty winds this afternoon will give way to little to no winds tonight into Friday morning with lows in the lower 30s. Sunny skies return Friday and with some slight air mass modification expect highs in the middle to upper 50s.

SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/

An upper air pattern featuring a ridge along the West Coast and a trough over the East will amplify late this week. One weak shortwave will exit the Mid Atlantic coast Friday, followed by a much stronger shortwave diving south across Manitoba and across the western Great Lakes on Saturday. Sensible weather here at the surface will remain much more benign late this week with mostly clear skies and near-normal temperatures as a deep and rather dry westerly flow aloft continues.

LONG TERM /SUNDAY THROUGH THURSDAY/

...An impactful cold weather event is expected early next week...

A powerful shortwave will dive southward from the Great Lakes to North Carolina and Virginia Sunday into Sunday night. Just ahead of the trough the accompanying arctic cold front should move across the eastern Carolinas and offshore during the day Sunday. Models generally paint mid-range (30 to 60 percent) rain chances along the front as shallow Gulf moisture routed up through Texas and then eastward along the front reaches this area.

The action starts as soon as the front is offshore: intense cold advection will steepen low level lapse rates to dry adiabatic with 30 mph wind gusts ushering in the coldest air of the season so far. After morning highs in the 50s Sunday, temperatures should sink through the 40s during the afternoon and crater out in the 17-21 range late Sunday night, the coldest since the January 22-23 arctic blast earlier this year. This should be the very definition of an "advective freeze" as 1500-2500 feet of vertical mixing maintains breezy winds through the night. Minimum wind chill values by sunrise Monday should reach the single digits, likely necessitating a Cold Weather Advisory for the entire area.

Despite sunshine, the airmass will be so cold highs on Monday may only make it into the upper 30s. The arctic high will settle across the area Sunday night with winds anticipated to go calm. After collaboration with our neighboring NWS offices, we've adjusted forecast temps downward by several degrees with Monday night's lows now expected to reach 20 inland and mid 20s on the beaches. Normal cold spots (Holly Shelter Gameland, Green Swamp) will undoubtedly run much colder during this "radiational freeze" event.

The upper air pattern should become more zonal later next week with dry weather and moderating temperatures expected.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Some gusty winds this afternoon and if you look really hard a few convective clouds to the northeast will give way to clear skies tonight with all but calm winds. VFR conditions expected through the forecast period.

Extended Outlook...Predominantly VFR through the extended period.

MARINE

Through Friday...Northwest winds of 10-15 knots will be in place across the waters overnight and turn a bit more westerly Friday. Speeds will diminish into early Friday as well falling to 5-10 knots briefly. Later in the day a southwest flow develops on the order of 10-15 knots. Significant seas of 3-5 feet will fall into a range of 2-4 feet.

Friday night through Tuesday...Moderate westerly winds are expected Friday into Friday night as a fast-moving clipper type low zips across the Mid Atlantic states and offshore. Winds will diminish to 10 knots Saturday and back around the southwest Saturday afternoon and Saturday night in advance of an approaching arctic cold front that should reach the area Sunday.

This front promises to bring a period of strong offshore winds Sunday into Sunday night with new models showing an increasing potential for gale force gusts. Also of importance will be the very cold temperatures: even over the water air temps in the 20s will make wind chill readings plunge to between 10-15 degrees F Monday morning.

A small 9 to 10 second southeast swell will be masked by westerly wind chop Saturday into Saturday night, then again by strong northerly waves Sunday afternoon into Sunday night during the arctic surge. Combined sea heights Sunday night could reach 6 feet near 20 miles from shore.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...None.