textproduct: NWS Wilmington

WHAT HAS CHANGED

Discussions updated. The risk for a widespread freeze continues to increase and now includes both Saturday night and Sunday night.

KEY MESSAGES

1) Above normal temperatures will continue ahead of a cold front on Thursday, followed by well-below normal temperatures over the weekend into early next week. Frost/freeze potential exists on multiple nights this weekend.

DISCUSSION

KEY MESSAGE 1...Above normal temperatures will continue ahead of a cold front on Thursday, followed by well-below normal temperatures over the weekend into early next week. Frost/freeze potential exists on multiple nights this weekend.

Above-normal temps will continue in southwest to west flow ahead of an approaching trough through Thursday. This trough in the jetstream will push a cold front through late Thurs, ushering in much colder and drier air comparable to mid-January normal temps, which is climatologically the coldest part of Winter. Ahead of the cold front on Thursday breezy southwesterly winds will maintain warmer temps but as they shift to northwesterly Thursday night much colder air will make its way in. This front will have very limited moisture to work with, keeping rain chances slim to none.

Secondary shot of cold air will arrive late Fri with considerably colder and drier air filtering in behind it, likely bringing nighttime lows down into the 30s away from the immediate coast. The risk for frost should be limited by both steady northwest winds through the night and increasingly dry air being brought in with those winds, but this will need to be monitored in case wind speeds drop low enough or dry air is slower to come in.

The cold air mass will be reinforced by high pressure northwest of the area, keeping north to northwest winds in place through the weekend and into early next week. This is expected to result in highs reaching only the mid-upper 50s and nighttime lows in the low- mid 30s, with chances for a widespread freeze increasing away from the immediate coast on Saturday night and Sunday night. North winds are still expected into early next week as high pressure remains northwest of the area, keeping well-below temperatures in place.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

A light SSW to SW flow will veer toward daybreak and become gusty and will continue to increase with gusts up to 20 kts or so out of the WSW after 14Z Thurs ahead of a cold front. Winds tonight should prevent fog formation, but should continue to see some streaming cirrus and possibly some high SC early Thurs.

Extended outlook... VFR through at least Wednesday night. Low chance for MVFR cigs Thursday morning ahead of a strong cold front, but confidence remains low. Otherwise, VFR from Thursday into the weekend.

MARINE

Mostly benign marine conditions will continue through late today with southwest to west winds mostly 15 kts or less. SW to W winds should increase tonight ahead of a cold front with elevated/gusty west to northwest winds behind the front peaking Thursday afternoon into Thursday evening. Although marginal, a brief Small Craft Advisory has been issued mainly due to frequent 25kt gusts Thursday afternoon into Thursday eve. Also issued a Gale Warning, mainly for waters beyond 30 nm north of Cape Fear. Winds will subside somewhat over Thursday night and remain mainly 10 to 20 kts Friday through Saturday night as they slowly veer from NW to N.

Seas will begin increasing into tonight rising from less than 3 ft this afternoon up to the 3-6 ft range out to 20 nm by Thurs eve and 6-8 ft in the 20 to 60 nmi waters before subsiding somewhat on Friday. Seas will drop further as winds diminish Saturday through Sunday. An easterly swell will be a dominant contributor to the wave spectrum through today with a period between 9 and 11 seconds before wind waves become the primary contributor from Wednesday night through the weekend.

ILM WATCHES/WARNINGS/ADVISORIES

NC...None. SC...None. MARINE...Small Craft Advisory from 10 AM Thursday to 1 AM EST Friday for AMZ250-252-254-256. Gale Warning from 2 PM Thursday to 1 AM EST Friday for AMZ280.