All Zones Evening Update, Snow Ends & Freezing Drizzle/Rain Threat Overnight. JT.

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Forecast Discussion:

CURRENTLY: Snow continues to move off to the east and northeast across the forecast zones this evening. Snow is moving out of Illinois and western Indiana. However, snow is still falling across most of the region, with some heavy snow in southeastern Indiana and southern Ohio.


Snow will continue to the east and northeast this evening. It looks like most of the snow will be out of Indiana and the majority of Illinois by 7-8 PM.


This evening there is a 500 mb vorticity maximum that is traversing across northern Illinois and will move into northern Indiana around 10 PM this evening.


With this moving into the region snow chances will remain across the northern half of Indiana/southern Michigan around 10 PM, then that snow will move into northern Ohio around 11 PM to 12 AM.


Overall it looks like most of the snow will come to an end around midnight across most of the area. The latest HRRR still showing some decent snowfall amounts possible across southern Ohio before the snow comes to a complete end tonight.


Winds overnight start to slack off, but gusts of 15-20 MPH will be possible, so some blowing snow overnight will remain possible.


Overnight we will see mid to upper level of the environment dry out. However, there will be lots of low-level moisture in place. With this kind of environment it will set up for the potential for some freezing drizzle/freezing rain overnight. You can see the skew-t suggesting overnight freezing drizzle/rain across the zones, along with the GFS model.



GFS Freezing Rain
GFS Freezing Rain

The best way to decipher where the potential for that freezing precipitation could occur is by using 925 mb relative humidity. Anything in the darker greens and blues would suggest enough moisture to have freezing rain/drizzle fall. By 1 AM you can see that includes much of the forecast area.

1 AM

By 4 AM there is some dry air working in across zones 6/7 in Illinois, but again still lots of moisture at low levels.

4 AM

Around 7-8 AM drier air looks to be in place across southern Illinois and western portions of zone 1 and 5. However, in places like Indianapolis, Cincy, Ft. Wayne, and Dayton the freezing drizzle/rain remains a threat for the Monday morning commute. Models are not picking up on significant amounts of freezing precipitation. However, where this does fall through the overnight it will make for slick conditions for the morning rush hour.

7 AM

Through the daytime hours tomorrow low-level moisture looks to remain in place.

7 PM


However, the big question will be how warm do we get. The NAM model does suggest many areas get above freezing mid to late Monday afternoon. However, I will admit I am a bit skeptical as clouds, moisture, and snowpack could keep those temperatures a few degrees cooler than the model guidance would suggest.


Below I have included a gif image of the 925 mb humidity from 1 AM Monday morning to 7 PM Monday evening to give you a little better idea of what to expect in your location.


By late Monday night into Tuesday night another clipper system looks to move into the forecast area from the northwest. The models are suggesting that on the south side of the low temperatures will be warm enough for rain, but with snow in place I think that may hold temperatures down. So snow becomes more likely to be the dominate precipitation type.


Here is the 24 accumulated snow from Monday through Tuesday morning per the NAM.

tues snow