HIGH WIND WARNING IN EFFECT FROM WEDNESDAY MORNING TO WEDNESDAY LATE NIGHT FOR THE ENTIRE TSWW COVERAGE AREA!
What a morning Monday morning was across the tri-state! Sheesh. As I said on Twitter sometime around 8:45 this morning...I've not seen a traffic map as red as the one I saw around that time, in a LONG time.
Well...we're not done with the wintry stuff. In fact, we'll only get about a 24-28 hour break from it.
As we go into your Tuesday afternoon, a low will scoot into southwest or central Missouri then eject into the Central Great Lakes by Wednesday. As that happens, a warm front will be moving north across Greater Cincinnati during the afternoon.
There's one thing here that could be a problem - and the National Weather Service has pinpointed it. It's a little thing called Isentropic Lift, or basically, lifting of air along a sloping surface. As that happens on Tuesday, we're going to start out with a mix of rain, sleet, and snow (more frozen the further north you go, more liquid as you go south - Central KY should be mostly rain so the bigger issue there is amount). Yours truly had a quick talk with WKRC-TV 12 meteorologist John Gumm - we're both in agreement that, by and large, daytime highs won't get out of the 30s. I'm going with 37, Mr. Gumm's thought was 39 and I think either is reasonable depending on the onset of precipitation.
The warm front comes through sometime just about rush hour Tuesday afternoon in the metro. This warm front will bring winds around to the south and southwest for Tuesday night and the first part of Wednesday, and the result is that any frozen precip that mixes in during the afternoon turns to all liquid rain Tuesday mid-evening at the latest. The result of this warm front also will be a RISE in temperatures. What's wrong with that picture? Normally, we lose the heating of the day in the nighttime hours. Because we'll be under the influence of something called Warm Air Advection, or WAA, the result is warming temperatures into the lower and perhaps even middle 40s by the early hours of Wednesday.
Now, things get interesting. As the low passes, the pressure gradient will tighten, which will cause the air to move faster between the high pressure to the southwest and the low pressure to the north. If you have an understanding of this process, you'll know this gradient is how we get wind. Well...there will be a SCREAMING low level jet stream at about 900 millibar level (or approximately 1 kilometer up in the atmosphere) of about 50 knots. Translate this down to the ground and you'll get 57.5 miles per hour - or roughly, high wind warning criteria. This level looks to be met for a short period at least on Wednesday. Meanwhile, you have the cold front coming through Wednesday morning, sometime between 4-8 AM.
Remember that Warm Air Advection I spoke of? Well, here comes the exact opposite, Cold Air Advection, and with a big time vengeance. Temperatures, remember, will begin Wednesday in the middle 40s for many spots especially south. That cold air comes in on winds that will be switching to the northwest and HOWLING between 40 and 45 miles per hour with gusts to 55 or 60. The temperature, then must respond and does so in dramatic fashion, PLUMMETING through the 30s, and (MAYBE) clear into the 20s by nightfall around 6-7 PM! There goes the bottom... and what happens to any moisture left over? Snow flurries at LEAST, possibly snow showers on Wednesday afternoon as we drop the temperature.
This post has already gotten too long, so part two will come later this evening. I may have an adjustment or two, but I think this looks good right now.
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