textproduct: Wilmington

WHAT HAS CHANGED

A mention was added of the potential for light snow later this evening and Sunday night. Additionally, after the period of bitterly cold temperatures, several systems will bring the next chances for frozen precipitation. While exact details are unknown at this time, these systems are discussed below.

KEY MESSAGES

1) Bitterly cold temperatures are forecast Saturday night through Wednesday morning with the coldest temperatures occurring Monday through Tuesday morning.

2) Chances for wintry precipitation remain in the forecast over the next week.

DISCUSSION

KEY MESSAGE 1... The first shot of cold air arrives later tonight into Sunday morning as temperatures drop into the teens area wide. Wind chill values will be in the single digits to near zero for much of the area.

Another reinforcing shot of cold air arrives Monday morning. Behind the front, cold, westerly winds drop temperatures into the teens during MLK Day. Forecast wind chills fall into the single digits below zero along and north of I-70 by the afternoon. Wind chills south of I-70 remain slightly warmer, but are only in the single digits above zero. Temperatures really drop off Monday night with forecast lows in the lower single digits. Although winds should slacken a bit with high pressure building into the region, forecast wind chills may fall into into the the -10 range late Monday night and early Tuesday morning. To learn about the warning signs of hypothermia and frostbite as well as how to protect your livestock and pets, visit www.weather.gov/safety/cold.

Now is the time to plan for an extended period of extreme cold by inspecting your residence, vehicle, and have plans in place for outdoor livestock. For information on how to prepare yourself, your home, and your car for extreme cold, visit www.weather.gov/safety/cold-before.

Some moderation is forecast Tuesday and Wednesday before another cold front drops temperatures one again for the end of the week.

KEY MESSAGE 2...

Snow chances this evening and tonight: With the large trough still over the region, minor snow accumulations with weak areas of atmospheric upward motion can not be ruled out this evening. Latest water vapor imagery shows the base of the trough ridging back to the north after the initial round of snow showers this morning. As a result, the advancement of the cold front eastward has slowed over the area. The next shortwave within the trough will drive the cold front through this evening, brining in cooler air. Aloft, the slight amplification to the flow will allow for a period of upward motion over the area. Given the cooler air aloft, saturation and lift within the DGZ will lead to a period of light snow, primarily along I-71 and south. For now, have limited snowfall accumulation to a couple tenths of an inch as low level dry air moving in with the front will assist in sublimation.

Snow chances Sunday night into Monday: As the main surge of colder air arrives to the area Monday morning, the leading shortwave will provide an opportunity for upward motion as the cold front approaches. Given the cold conditions, any lift and saturation aloft is likely to be within the DGZ, supporting effective snowfall production. While accumulations will be limited, even a half inch of snow leading into the Monday morning commute could be impactful.

Wednesday-Friday: After the bitterly cold air mass moves out, there are significant disagreements in the placement of temperatures across the region as the next two systems in. The first arrives on Wednesday with the second possible at the end of the work week or into the weekend. On Wednesday, confidence is a little higher that the residual cold air mass will still be in place, providing a chance for snow. If the system is strong enough, warm air moving in from the southwest will result in some mixed precipitation in the south. When looking at the end of the week, the 00Z cluster analysis indicates the GEFS and GEPS are much warmer than the ECMWF ENS. The ENS is cooler and as a result, much drier than the other two ensembles. This similar bias is observed within each of the 12Z AI versions (AIGEFS, AIFS ENS), creating considerable uncertainty for late in the week. Due to this, no changes were made from the NBM.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

Areas of light snow will shift east across the region this evening in association with an upper level trough. In areas of snow, some occasional MVFR cigs and vsbys will be possible early in the TAF period. Otherwise, expect VFR stratocumulus to persist through much of the night before scattering out as we head into Sunday morning.

OUTLOOK...Winds may gust up to 30 kts Monday.

ILN WATCHES/WARNINGS/ADVISORIES

OH...None. KY...None. IN...None.