Nowcast Northern Snow System

I cannot believe JCPS (Jefferson County Public School) called off school again. When 2-hour delays or, in this case, 2-hour dismissals would have sufficed, the schools are abruptly called off for the day. At least monitor the ongoing forecast or nowcast as the system approaches. Perhaps make a decision by noon. I know there would be buses on the roads even after 3:00pm with an early dismissal, which does coincide with the arrival of snow, but the current RAP short term model continues to indicate the freezing line just above the surface runs right through Louisville. However, you couple that with the daytime heating's effects at the surface, the snow is not going to stick to the pavement right away, especially if our precipitation starts out as a mix of rain and snow.

I raise this issue about abrupt school closings because earlier this week, JCPS closed school before even trying to see if a 2-hour delay would have given more time for the snow to melt from the roadways, especially those non-treated side streets.

Anyway, enough with that rant. We are in nowcast mode. I will say that the NAM 06z and 12z runs from yesterday painted a beautiful swath of 1-4" amounts for southern IN into north-central KY and the Bluegrass.

The RAP model (11z run) shows that the accumulating snow line is very close to Louisville throughout the daytime hours. If we get snow accumulation, it would be confined to the existing snowpack, not treated area roadways as temperatures will be close to the freezing mark.

Based on the current information, any snow falling by late afternoon when the daytime heating's effects will be reduced, area roadways will become negatively impacted. With this nowcast post, Louisville looks to get 1-2".

I will update this page by noon time. Then, we'll see if JCPS made a good decision or not. Coordinating with the NWS, which I'm sure they do, any nowcast leanings toward negative travel by 3pm will hopefully be more clear.

Don't jump the gun JCPS. Let the good folks at the NWS help assay the situation. I believe sometimes, our media sites get a little too excited and distort the school system's ability to wait for any change in the ongoing forecast before making a final decision. Perhaps a final decision helps parents coordinate or plan what to do with the kiddos instead of struggling with what to do with an early dismissal? With that said, by the end of the day, the decision to close school will probably be the right call.
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10:15am
Winter Storm Warning for locations just across the River extending into parts of the Bluegrass.
Louisville not included, yet.
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11:00am
NWS Louisville:
4-6" for areas just across from Louisville and rest of warned area
1-4" for Louisville
Wave3 in Louisville has been leading the way
RAP 13z shows heaviest snow just north and northeast of Louisville with little or no accumulation just south of Louisville.
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1:00pm
Still, no precipitation reaching the ground as of noon. But, it does appear Evansville could be shortly. Indy already reporting snow with temperature of 19 degrees.
15z RAP shows moderate snow in southern IN and Louisville area between 4 and 5pm. However, snow totals still look tame according to these runs, generally an inch or two for Louisville with maybe 3-4" north and northeast of Louisville.
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3:15pm
Rain at Paducah, Owensboro, Louisville, Fort Knox with temperatures still well above freezing. Snow has been reported mixing in with the rain at times. It will take some time before cooling at the surface supports snow sticking to the pavement unless a heavy band overcomes the warmer ground. Across the River from Louisville, at least not too far away, snow is falling.
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4:00pm
Light rain at Valley Station and 37 degrees.
RAP 18z still shows heaviest snow just north and northeast of Louisville.
Expected changeover after 5pm.
JCPS should have went with early dismissal; oh, well. Jefferson County Catholic dismissed early, no makeup day for them.
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4:15pm
2.3" snow accumulation in Paoli IN. Floyds Knobs 1-1.5".
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4:40pm
NWS Louisville has Jefferson County in 2-4" range.
I still think parts of the county will only see an inch while others in the county may see  4" or more.
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5:00pm
Rain drops are beginning to take on more of a snow consistency. It's not a true snowflake yet but is beginning to transition in Valley Station.