textproduct: Wilmington

SYNOPSIS

A cold front will bring colder temperatures to the region this afternoon and evening, with some snow expected through the evening hours. Much cooler air will be in place for Thursday and beyond, with especially cold conditions early next week. The next chance for snow will be on Friday and Saturday, as another low pressure system moves through the Great Lakes.

NEAR TERM /THROUGH TONIGHT/

Two separate areas of precipitation exist across the area early this afternoon. The southern band has been stretched out from eastern Ohio down through southern Ohio and northern Kentucky throughout much of the day. Rain has been been persistent, but it has only been able to produce between two and three tenths of an inch for the most part. The second area of precipitation is only beginning to work into portions of west-central Ohio as of this writing. While some light rain may be experienced ahead of the approaching cold front, the heavier precipitation rates are likely to be all snow as it moves through. Quickly behind the snow showers, much cooler air will move in, with temperatures dropping 15 degrees into lower 30s and upper 20s.

Snow showers may be enhanced at times, but given relatively warmer temperatures ahead of the front and daytime hours, roadway impacts are expected to be fairly isolated over the next few hours. However, as colder air moves in, a band of lingering snow is expected behind the showers/cold front. Over time roadway temperatures will decrease, especially where snow continues behind the front. Current guidance suggests this scenario is more likely along an area from west-central Ohio into central Ohio, where between a half inch to an inch and a half is forecast. This is a slight bump up from previous forecasts, and it is based on latest short term guidance, radar observations, and collaboration with surrounding offices.

Evening slick spots: Colder air, gusty winds, and ongoing snow will eventually result in a higher chance for the development of slick spots this evening. Central Ohio will likely be the best chance for the band of snow behind the front to cause impacts during the evening due to the later arrival. In addition, lake effect/enhanced snow bands and general snow showers will drift southeastward toward and through the local area, which cold lead to slick spots in eastern Indiana, as well as portions of Ohio.

Cold temperatures late Wednesday night into Thursday morning: Temperatures drop into the teens overnight with elevated winds resulting in feels-like temperatures in the single digits area wide and to near zero across central Ohio.

SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/

Can't rule out a few isolated snow showers or flurries throughout the first part of the day, but eventually the moisture shifts to the east as a brief ridge builds in during the afternoon. High temperatures are chilly during the day (about 10 degrees below normal) as the cold air mass persists.

As the next system moves in late Thursday night into Friday morning, warm air advection will lead to an area of light snow or snow showers. With this being a warm air advection setup, thermal profiles do not favor efficient snow rates, likely leading to small snowflake sizes. However, given the cold temperatures during the preceding 24 hours, even light snow a few tenths of an inch could lead to impacts to the Friday morning commute. The biggest uncertainty at this time is the overall coverage of the light snow given the atypical snow generation pattern. For now, will continue to mention the chances for snow across Friday and Saturday in the HWO.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Persistent longwave ridge will remain positioned well off the U.S. East Coast with a digging trough axis from the Great Lakes back though the Midwest. Despite deep southwesterly flow over the middle Ohio Valley, surface temperatures will remain near middle January normal values.

The initial mid-level shortwave ejecting out of the longwave trough will affect our CWA on Friday, offering a period of snow showers. Accumulations should be on the light side due to light QPF (less than a tenth) as well as the snow falling during daylight hours. A stronger shortwave will arrive on Saturday, with a cold front associated with this system shifting through our area Saturday night. More light snow is expected... however the primary impact will be the arctic air following behind the front. High temperatures may not reach 20 degrees on Sunday with low temperatures dipping into the single digits to near 10 degrees for both Saturday and Sunday nights. The coldest night of the period looks to be Monday night, with temperatures falling to near zero with wind chill temperatures as low as -5 to -15. Exact values will depend of the amount of clearing we see and also how much snow is on the ground. Surface high pressure will build over the Ohio Valley on Tuesday with a continuation of cold conditions.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

Generally observing MVFR CIGs and VIS across the area this afternoon as a band of light rain continues across southern and central Ohio. Attention shifts to the cold front moving in through the rest of the afternoon and evening, causing winds to shift more northerly, increasing in magnitude as they do so. Wind gusts in the 25 to 30 knot range are expected this evening along with precipitation.

With the colder air moving in, snow showers are the main concern, resulting in periods of MVFR VIS at local TAF sites. CMH/LCK have a better chance of seeing more persistent this evening after the snow showers, and that has been noted from 21Z-00Z this evening.

As the main precipitation moves out, northwesterly winds remain elevated with scattered snow showers. PROB30s were used to highlight this threat but overall, the impacts will vary at each TAF site as the showers move through.

Eventually have MVFR conditions breaking during the overnight or early Thursday morning.

OUTLOOK...MVFR conditions are possible Friday into Saturday with snow. Gusty winds are also possible Friday into Saturday.

ILN WATCHES/WARNINGS/ADVISORIES

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