textproduct: NWS Wilmington

WHAT HAS CHANGED

Marine Update for raising a Gale Warning for the ILM NC Waters only, Surf City NC to Little River Inlet SC, in effect from 4am Sat thru Midnight . Latest high res models and 18Z global models indicate what was borderline Gale sustained thresholds should atleast observe occasional gusts to 35 to 40 kt. After the Arctic frontal passage, winds at 2k ft will run 40 to 50+ kt and should observe mixing as gusts to the ocean sfc even with SSTs in the 40s nearshore to around 50 20 nm out given the influx of Arctic air. Plenty of air-sea interaction, especially when that air reaches the "warm" Gulf Stream waters offshore. Will re-run NWPS to incorporate seas with the updated fcst wind field.

Aviation discussion updated for the 00Z TAFs.

KEY MESSAGES

1) Particularly cold weather will be in place Saturday through Sunday night. A Cold Weather Advisory for wind chills 10-15 degrees is likely Saturday night into early Sunday morning.

DISCUSSION

KEY MESSAGE 1: Particularly cold weather will be in place Saturday through Sunday night. A Cold Weather Advisory for wind chills 10-15 degrees is likely Saturday night into early Sunday morning.

A series of cold fronts tonight and Saturday followed by Arctic high pressure Sunday will lead to dry, cold conditions through the weekend. A moisture starved cold front will push through tonight with a slight chance of showers for our northernmost areas this evening. This will be our first push of cold air which will be enhanced Saturday as a jet aloft with another surface cold front pushes off the NE coast, with us on the southern edge of it. These stronger winds aloft (~30-35 kts) should mix down during the daytime manifesting as wind gusts 30-40 mph. This paired with highs in the upper 30s-lower 40s will make Saturday afternoon wind chills around or below freezing (a -10 deg difference from the forecast highs). This cold will continue into Saturday night where an overnight breeze will linger, dropping wind chills below 15 degrees to where a Cold Weather Advisory will likely be needed over a majority of the area, with some uncertainty for our westernmost counties. Arctic high pressure will then ridge over the area for Sunday with similar temperatures to Saturday but much less in the way of winds. There is some uncertainty around Sunday night where lows could end up several degrees cooler than currently forecast due to radiational cooling from calm winds and mostly clear skies. A Cold Weather Advisory should not be needed, and this will be the end of the cold weather as we warm up into early next week.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

VFR conditions through the 00Z Taf Issuance Period. Arctic front to push across the area and offshore later this evening into the overnight. Will see bouts of stratocu and altocu decks ahead of it this evening. Main issue will be the veering winds to the NW after FROPA, followed by CAA surge and a tightened sfc pg yielding NW winds gusting to 30+ kt at times during daylight Sat. Prior to the gustiness, have continued with the LLWS advertisements with speeds at 40 to 50+ kt at 2k ft being progged.

Extended Forecast...Flight restrictions from Ground fog could develop late Mon night and Tue morning, with periodic sea fog possibly impacting the coastal terminals Mon night thru Wed.

MARINE

Through Saturday...A cold front will move through tonight with winds and seas increasing, gusts 25 kts and 6 footers ~20 nm out. A second front will push through Saturday with stronger NW winds gusting ~30 kts. A few, infrequent Gale Force gusts may be possible.

Saturday night through Wednesday...Gusty northerly winds Sat evening will begin to subside into Sunday as gradient relaxes. Winds become lighter and a bit more variable into Monday as the center of high migrates nearly overhead. By late Mon into Tues, the high sinks south and east leaving a more SW return flow across the waters. Winds up to 30 kts Sat eve will drop to 5 to 10 kt by Sun aftn and remain light through Tues. Seas respond as well, with heights up to 4 to 6 ft Sat night dropping down to 2 to 4 ft on Sun leaving a longer period easterly swell Sun into Mon.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...Small Craft Advisory until 4 AM EST Saturday for AMZ250-252. Gale Warning from 4 AM Saturday to midnight EST Saturday night for AMZ250-252. Small Craft Advisory until 7 AM EST Sunday for AMZ254. Small Craft Advisory until 7 AM EST Sunday for AMZ256.