textproduct: NWS Wilmington

WHAT HAS CHANGED

Updated for 12Z TAF discussion.

KEY MESSAGES

1) Dangerous travel conditions will continue today and possibly tonight as cold temperatures remain in place across the area. These cold temperatures will limit daytime melting on area roadways and allow for re-freezing tonight.

2) Low pressure moving eastward along a cold front will bring a good chance of rain Wednesday, possibly ending as a little wintry mix late Wednesday night or Thursday morning.

3) Well below normal temperatures will continue through late this week.

DISCUSSION

KEY MESSAGE 1: Dangerous travel conditions will continue today and possibly tonight as cold temperatures remain in place across the area. These cold temperatures will limit daytime melting on area roadways and allow for re-freezing tonight.

Area roadways remain snow-covered and treacherous this morning. Temperatures prior to sunrise will dip into the low to mid teens dependent on local snow cover and winds (some areas could drop into the single digits). Any partially melted areas of compacted snow and ice have already re-frozen and will be reinforced by the frigid temperatures this morning. This will make for a dangerously slick morning commute, so please stay off the roads if at all possible. A Winter Weather Advisory remains in effect for these poor driving conditions until temperatures rise above freezing around midday.

Don't become too overconfident when driving on sections of roadway that dried-out on Sunday. Road conditions will change quickly throughout your commute: high speeds on dry pavement will not translate well to ice-covered sections of your route.

Temperatures will rise above freezing around midday across the region and full sunshine should help with some melting. However, tree-covered areas will be slower to improve. A cold and dry air mass in place will allow temperatures to crash as the sun sets this afternoon. We will quickly fall below freezing this evening and any melting that occurred will again re-freeze into areas of compacted ice and slush.

Low temperatures and light winds tonight may prompt the issuance of a Cold Weather Advisory for parts of the area tonight where temperatures (and to a lesser extent wind chills) drop to around 15 degrees, but confidence remains low. Light southwest winds make tonight's temperature forecast a bit tricky. If boundary layer winds remain light, the radiational cooling potential with snow on the ground is quite high and we could be a few degrees too high with the latest forecast. However, if light winds hold over the area, very few of our forecast zones would touch the 15 degree criteria.

KEY MESSAGE 2: Low pressure moving eastward along a cold front will bring a good chance of rain Wednesday, possibly ending as a little wintry mix late Wednesday night or Thursday morning.

Models have not changed appreciably over the past 12 hours with their depiction of surface low pressure riding along with an eastward-advancing cold front reaching the Carolinas Wednesday/Wednesday night. The upper level pattern looks rather messy during this time with several shortwaves outlining a broad positively tilted trough over the eastern U.S. Mid level flow should become just southwesterly enough to tap some Gulf moisture and column precipitable water values should rise to just above 1 inch Wednesday. PoPs are being maintained in the 60-70 percent range.

A surface cold front should push off the coast Wednesday night. Shallow low level cold advection will develop behind this front while 6-8kft of moisture remains aloft within the frontal inversion. It's possible that surface temperatures could dip low enough late Wednesday night into early Thursday morning for some freezing rain or even a little snow to fall as precipitation is wrapping up across southeastern North Carolina. Potential amounts should be very small and there is not universal agreement in models that cold air will build in fast enough or that sufficient moisture will linger for precipitation issues to arise. Regardless, deep dry air will build in Thursday with forecast precipitation chances rapidly dropping away during the morning hours.

KEY MESSAGE 3: Well below normal temperatures will continue through late this week.

Each day since January 24 has had colder than normal daily average temperatures. The next seven days should also have below-normal temperatures including some chilly nighttime lows coming up Thursday night and Saturday night. Saturday night's forecast lows in the lower 20s may exist concurrently with enough wind to reach the 15-degree wind chill trigger for a Cold Weather Advisory, particularly across inland southeastern North Carolina.

Using our observed highs and lows since January 24 plus our forecasts through Feb 8, Wilmington's 16-day average temperature could end up the lowest since the long stretch of cold weather from 12/25/2017 through 1/9/2018.

AVIATION /12Z MONDAY THROUGH FRIDAY/

High confidence VFR. Light NW winds turn SW this evening as high pressure moves west to east across Florida.

Extended Forecast... Mainly VFR. A cold front will bring the next chance of widespread precipitation along with restrictions late Tuesday night through early Thursday.

MARINE

Through Tonight... Rapidly improving gradient has seen a decrease in gusts and seas across the region. The Small Craft Advisory has been canceled and conditions will continue to improve today as high pressure traverses FL from west to east. Winds become westerly tonight around 10-15 knots as seas continue to decrease to 2-3 feet by this evening.

Tuesday through Friday Night...High pressure centered across Florida Tuesday morning will move out to sea, allowing our winds to back to the southwest during the afternoon. Speeds should increase to 15-20 kt Tuesday night ahead of an approaching cold front that should reach the coastline Thursday evening. Winds will abruptly shift to the north and northeast behind the front Wednesday night. There's a small potential for winds/seas to reach Small Craft Advisory criteria Thursday morning near Cape Fear, but this should be a short- lived marine event if it occurs at all. Winds should gradually diminish Thursday morning as high pressure centered across the Gulf extends a ridge axis across the Carolinas. The next approaching front could lead to increasing again on Friday with Small Craft Advisory possible Friday afternoon into Friday night.

CLIMATE

Record Low Temperatures for Feb 2 - Feb 3 ILM: 17 in 1980; 13 in 1917 FLO: 18 in 1980; 19 in 1980 CRE: 20 in 1945; 19 in 1942 LBT: 11 in 1980; 13 in 1980

ILM WATCHES/WARNINGS/ADVISORIES

NC...Extreme Cold Warning until 10 AM EST this morning for NCZ087- 096-099-105>110. Winter Weather Advisory until 11 AM EST this morning for NCZ087-096-099-105>110. SC...Extreme Cold Warning until 10 AM EST this morning for SCZ017- 023-024-032-033-039-054>056-058-059. Winter Weather Advisory until 11 AM EST this morning for SCZ017-023-024-032-033-039-054>056-058-059. MARINE...None.