Will The Snow Be a Big Deal???

You know, when it's springtime, snow just does not fit the scene or at least it shouldn't. Forecasts are calling for snow for at least the northern half of our region. In fact, the favored NAM has taken the Low a little farther south than yesterday. Therefore, this means that those areas north of us that were expecting 1-2", those possible accumulations have now shifted into the Louisville area and across the Bluegrass region.

I'm still awaiting some data that should have already been released by now. If there's any significant change in that data, I'll quickly report back. But, for now, here it is:

I do like the NAM's presentation of the storm system. However, either I'm having problems decoding the temps aloft and at the surface for this event or else the professionals have it wrong. OK, let's go with the pros. Here is a partial statement from the NWS here in Louisville:

MOISTURE DOES NOT ARRIVE UNTIL AFTER 18Z ACROSS SOUTH CENTRAL KENTUCKY. WIDESPREAD RAIN SHOWERS WILL THEN OVERSPREAD THE ENTIRE AREA DURING THE LATE AFTERNOON AND EARLY EVENING...WITH MOSTLY RAIN EXPECTED BEFORE 8 PM EDT...

EXPECT A RAIN SNOW MIX TO QUICKLY CHANGE TO MOSTLY SNOW BETWEEN 8 PM AND 11 PM EDT ACROSS EXTREME NORHTERN KENTUCKY AND SOUTHERN INDIANA TONIGHT. THE RAIN/SNOW LINE WILL GRADUALLY SINK SOUTH OVERNIGHT...MAKING IT AS FAR SOUTH AS THE CUMBERLAND PARKWAY BY DAWN. SOUTH OF THIS LINE...

EXPECT ALL RAIN.

 

HOWEVER...WITH GROUND AND ROAD TEMPERATURES RUNNING WELL ABOVE FREEZING DO NOT EXPECT MUCH IN THE WAY OF ACCUMULATION ON ROADWAYS. FEEL A SOLID 1 TO 2 INCHES COULD ACCUMULATE ACROSS EXTREME NORTHERN KENTUCKY AND SOUTHERN INDIANA...MAINLY ON GRASSY AND ELEVATED SURFACES. THAT BEING SAID...HAVE BEEN TRACKING THE POTENTIAL FOR BANDING OF PRECIPITAITON WITH 850-700 MB DEFORMATION. THIS FEATURE HAD BEEN IN SOUTHERN INDIANA YESTERDAY...HOWEVER IS NOW ALONG THE OHIO RIVER AS TRACK OF SYSTEM HAS TRENDED SOUTH. AM CONCERNED ABOUT BANDING OF
PRECIPITATION JUST SOUTH OF THE OHIO RIVER WITH THIS FEATURE...WHICH
COULD YIELD ENOUGH OF A SNOWFALL RATE TO ACCUMULATE ON ROADWAYS.

Ok, with that said, their thinking is for a general 1-2" wet snow with some possible banding, which could end up putting down an additional 1-2" for storm totals of 1-4". Again, primarily on grassy surfaces.

What are my thoughts???
I'm no pro, but I will call it as I see it. The data that I'm awaiting will help me determine forecast temps at the 850mb level and near the surface. Here's a dilemma that I'm having. Rain should move into the area later today. Yes, it will be a cold rain with a raw northeast wind component. Sometime during the night, light to occasionally moderate snow will develop as the changeover occurs. What happens to the snow when it lands on the surface? It's already a wet surface and temps will quite likely still be at or above freezing. Unless the snow falls heavily for a period of time, even on the grass, significant melting will be occurring. Therefore, it will be difficult to ascertain how much snow accumulation we will have. I don't think we get much below freezing before the bulk of the precipitation moves out either.

During the heaviest parts of the storm, a quick inch or maybe two could occur. However, as soon as the precip lightens a bit, melting will already be affecting the snow pack. As I say, don't get too excited about this. The snow will likely not stick around long enough for us to enjoy it.

More updates later...
MS