Yet another winter storm is going to trek through the middle of the country over the next 72 hours, and yet again the Midstate will be very close the dividing line between “hey, it’s just rain” and…well:
Okay, so it won’t be THAT bad…but it looks like folks along and north of the Ohio River are going to be dealing with a significant freezing rain event late this weekend. Could it impact us? Sure. But here’s why I think the worst of it will avoid us…
Our pattern this winter (over and over and over) has been for winter storms to give us a lot of cold rain, but then the bulk of the moisture moves off to the east by the time the atmosphere gets cold enough to produce freezing rain or sleet or snow. As of right now (mid-afternoon Friday) that’s looking like the most likely scenario for Sunday night and early Monday.
The computers have some significant differences regarding exactly where the rain/freezing rain dividing line will set up — the left-hand images (RPM model) pretty much equate to being the “best-case” scenario, the right-hand images the “worst-case” (BAMS model). I lean toward the RPM model (left) at this point, but since we’re still more than 48 hours away from this developing, there’s still lots of us time for us to re-evaluate things.
It’s going to be a close call…but the storm system itself is still waaaaaaaaay out to our west. In fact, it’s still off the west coast. Out over the Pacific Ocean, we’re not able to get much “sampling” data of the upper atmosphere from weather balloons and wind profilers. The computer models that simulate the atmosphere’s behavior rely on that data to set their “initial conditions” — what the storm is doing now. If the initial conditions aren’t right, then the computer’s output won’t be right (the non-technical phrase is “garbage in, garbage out”). So, while we KNOW that the storm is out there (we can see it on satellite, and we’ve got some ocean buoy and ship reports), we won’t have a lot of the necessary information to put into the weather computers until the heart of the storm moves onto the west coast early Saturday. To make a long story short…
…we could still see some significant fluctuations to the forecast path of the entire storm system. But given what’s happened over and over this winter, a “wobble” of the storm track to the north seems like the most likely scenario.
The NWS offices in Memphis, Paducah and Louisville have already issued Winter Storm Watches for the counties shaded in white (notice that counties in the Channel 4 viewing area are on the fringes of all of the watches):
I’ll wrap this up by once again stealing Peter King’s idea of “10 things I think I think”:
1) I think we’ll see above-normal temperatures both Saturday and Sunday
2) I think we’ll get some spotty showers during the day both Saturday and Sunday
3) I think the heaviest rain (1″+) will fall late Sunday night…and it will be rain
4) I think that most of the Midstate will stay on the warm side of this system until very early Monday morning
4) I think we’ll see a brief changeover to ice/snow as cold air moves in Monday morning
5) I think that by the time temperatures drop, only a scrap of moisture will remain…so ice/snow will not accumulate across most of the Midstate, including Nashville
6) I think the western half of southern Kentucky and northwest Middle Tennessee have the best chance of seeing freezing rain or sleet that would actually accumulate
7) I think the worst problems due to accumulations of ice, sleet and snow will stay just outside the Channel 4 viewing area to the north and northwest
8) I think the “worst-case” computer models are too pessimistic right now
9) I think I’ll probably have to make a few adjustments to this forecast over the weekend
10) I think that if the month of March was a fictional character, it would be Jim Moriarty
Watch for updates this weekend!