textproduct: Wilmington

WHAT HAS CHANGED

Increased probabilities for snow tonight and Saturday. Also, bumped up snow amounts late tonight and Saturday.

KEY MESSAGES

1) Several opportunities for light snow are expected early this morning through Saturday. Chances of greater than one inch of total snowfall accumulation are highest (>70%) across portions of central, southwest, and southern Ohio.

2) Bitterly cold temperatures are forecast Sunday through Wednesday morning with the coldest temperatures occurring Tuesday morning.

DISCUSSION

KEY MESSAGE 1... Lead mid level shortwave to eject east-northeast from the Mid MS Valley thru the Great Lakes ahead of developing low over the Upper MS Valley. Isentropic lift will develop ahead of this feature this morning toward sunrise. Low level dry air will help to limit saturation of the snowfall to the surface, but forecast soundings indicate the potential for lift within the DGZ, supporting more efficient accumulation. Expect snow accumulations of several tenths of an inch with the highest confidence across east central Indiana and west central Ohio. This could lead to slick spots for the morning commute. Another period of light snow looks to develop this afternoon along and ahead of a frontal boundary. This accumulation looks to a half inch or less.

Focus shifts to potential for additional accumulating snow tonight into Saturday ahead of digging mid level trof. A secondary cold front arrives later in the evening, with the potential for scattered snow showers along and behind the front. Light accumulations with these snow showers could lead to challenging travel wherever the snow showers occur. These showers will be possible area wide. There is some increased confidence that the best lift and moisture looks to occur along and southeast of I-71. This snow looks to be in two enhanced periods - the first later tonight and a second more limited in coverage but having the potential for greater snow rates Saturday.

Probabilities of an inch or more have increased to greater than 70 percent later tonight through the day on Saturday. Have increased pops and snow amounts with generally a 1 to 2 inch amount thru this period.

KEY MESSAGE 2...

A prolonged period of bitterly cold temperatures and wind chills will be in place from Sunday through Tuesday night. Deep longwave troughing will be in place over eastern CONUS and various shortwave disturbances will bring reinforcing shots of arctic air down to the Ohio Valley region.

The entire forecast area should expect several days of single digit wind chills/ feels like temperatures during both daytime hours and overnight. The coldest period within this stretch will be Monday into Tuesday and we will likely need Cold Weather headlines at some point during this time frame. For NWS ILN headline criteria, visit www.weather.gov/iln/criteria-winter.

Monday daytime wind chills are forecast to fall to around 0 along and south of I-70, with wind chills as low as -10 for areas north. As we head into Monday night, the cold intensifies, with wind chills falling to -10 to -15 degrees across much of Ohio and Indiana, with -5 expected across northern Kentucky. Ambient air temperatures during this time fall to around 0-5 degrees area wide. Temperatures rebound slightly on Tuesday, rising into the teens and 20s during the day and falling to the single digits and teens overnight. By Wednesday, the deep layer trough flattens out a bit and we begin warm air advecting ahead of another shortwave system. Temperatures temperatures rise substantially to the 30s/40s.

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.

AVIATION /06Z FRIDAY THROUGH TUESDAY/

VFR conditions to start the TAF forecast period with mid and high level clouds increasing across the area this morning. A weak disturbance moves through the area may lead to some light snow around sunrise but generally VFR conditions are expected to continue into the afternoon.

Additional low chance threat for some light snow occurs this afternoon with increased chance for snow tonight. Ceilings drop to MVFR this evening with the potential for IFR ceilings and vsbys in snow overnight.

Southwest winds at 10 kts or less increase today with gusts around 25 knots. Southwest winds lose the gustiness this evening at 10 kts or less.

OUTLOOK...Wind gusts of 20-25 kts Saturday and 25-30 kts Monday. Vsbys and cigs will be reduced to IFR in snow showers Friday night through Saturday.

ILN WATCHES/WARNINGS/ADVISORIES

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