textproduct: NWS Wilmington

WHAT HAS CHANGED

18Z Aviation Discussion Updated.

The Winter Storm Warning remains in effect for the ILM CWA. The Gale Watch has been upgraded to a Gale Warning for the coastal waters Saturday morning through Sunday. The Cold Weather Advisory remains in effect for inland counties tonight, with an Extreme Cold Warning now out for Saturday night and Sunday morning. Another may be needed for Sunday night and Monday morning.

KEY MESSAGES

1) Confidence continues to increase in a significant winter weather event this weekend. Expect impacts to travel and infrastructure, ranging from hazardous to dangerous conditions and closures.

2) A very cold air mass paired with snowfall will result in dangerous cold and record low temperatures this weekend. Wind chill temperatures below 15 degrees will linger through at least Monday night/Tuesday morning.

DISCUSSION

KEY MESSAGE 1...Confidence continues to increase in a significant winter weather event this weekend. Expect impacts to travel and infrastructure, ranging from hazardous to dangerous conditions and closures.

Satellite imagery showing the large and strong mid level cyclone moving south of the Great Lakes already getting response down stream in the Tennessee Valley with plenty of virga and in short order expect surface observations to reflect precipitation. For our area there have been mixed trends with the all important snowfall amounts. The higher resolution guidance (HRRR and NamNest) have arrested the trend of drying and resumed snowfall amounts of four to approximately seven/eight inches. The 12 UTC GFS has trended lighter continuing from earlier. Overall we have trended down total snowfall amounts and in time may trend down further incrementally. Three noted features and or trends in the guidance...

First...a lower snowfall amount trend in between the higher totals (see weather.gov/ilm/Jan2018snow). This seems reasonable considering this analog and moisture/forcing being transferred to coastal areas. It is worth noting any drying trend then reverting back to a more moisture rich rendition may be expected. The storm last January (weather.gov/ilm/WinterStormJan2025) did this.

Second...generally higher amounts in the north and west counties seem reasonable as well as this has been the trend off and on and kinda more on.

Third...onset development has sped up and forecast has been adjusted as well citing forecast models and the aforementioned satellite trends. There could be some good snow late tonight into Saturday morning in western areas of the CWA.

KEY MESSAGE 2...A very cold air mass paired with snowfall will result in dangerous cold and record low temperatures this weekend. Wind chill temperatures below 15 degrees will linger through at least Monday night/Tuesday morning.

A Cold Weather Advisory will be in place tonight as wind chills drop below 15 degrees. An Extreme Cold Warning is in place for Saturday night through Sunday morning where wind chills will be near or below 5 degrees. What snow we get will be on the ground at this point and the system will be pulling away, leading to relaxing winds and somewhat recovering wind chills late in the day Sunday, but still very cold. This recovery also looks to be brief, and another Extreme Cold Warning may be needed Sunday night as we see single digit lows despite light winds, particularly inland. Temperatures will slowly recover through early next week with a bit of uncertainty in temperatures depending on how long the snow will stick around. For now, dangerous cold should come to an end Tuesday.

Several of our climate sites could see record lows during this weekend period, and possibly even Monday night though with a bit more uncertainty due to snowpack. Record lows for Feb 1 and Feb 2 are in the climate section below for reference.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

VFR conditions expected through this afternoon and most of the overnight hours. With snow developing west to east early Saturday have used PROB 30 then prevailing groups with this p-type. In time ceilings and visibilities will drop to IFR probably remaining just into MVFR this actual forecast period. Wilmington and Myrtle Beach will need Airport Weather Warnings with the onset of frozen precipitation mid to late day Saturday.

Extended Forecast. Flight restrictions expected through most of Sunday improving early next week.

MARINE

Through Saturday Night... The Gale Watch has been upgraded to a warning. While most of our gale watches are somewhat marginal the strength and or gradient with this system makes sustained 40 knots doable. Significant seas a little lower than what would be associated with such winds seem decent however considering the more offshore flow and limited fetch...5 to 8 feet.

Sunday through Wednesday... Gales and 5-8 ft seas are likely through Sunday until the low pulls away, where a Small Craft Advisory will be needed through at least Sunday night. Building high pressure should lead to rapid improvement through Monday with offshore winds generally 10 kts. SW winds will start to increase ahead of another system Wednesday.

CLIMATE

Record Low Temperatures for Feb 1 & Feb 2 ILM: 14 in 1936; 17 in 1980 FLO: 20 in 2010; 18 in 1980 CRE: 20 in 1945; 20 in 1945 LBT: 4 in 1936; 11 in 1980

ILM WATCHES/WARNINGS/ADVISORIES

NC...Cold Weather Advisory from 1 AM to 6 PM EST Saturday for NCZ087-096-099-105. Winter Storm Warning from 1 AM Saturday to 4 PM EST Sunday for NCZ087-096-099-105>110. Extreme Cold Warning from 6 PM Saturday to 10 AM EST Sunday for NCZ087-096-099-105>110. SC...Cold Weather Advisory from 1 AM to 6 PM EST Saturday for SCZ017-023-024-032-033-059. Winter Storm Warning from 1 AM Saturday to 4 PM EST Sunday for SCZ017-023-024-032-033-039-054>056-058-059. Extreme Cold Warning from 6 PM Saturday to 10 AM EST Sunday for SCZ017-023-024-032-033-039-054>056-058-059. MARINE...Gale Warning from 9 AM Saturday to 7 PM EST Sunday for AMZ250- 252-254-256.