1) January 21st/22nd (clipper snow)
ODDS AND ENDS
Our intern Sid covered the rain threat in the previous post---I wanted to focus on the cold temps tonight and impacts.
The models have varied some on how much cold air will be in place before the moisture heads out this evening. They have varied on freezing rain/sleet and even snow. I will say a warm profile like we currently have is hard to cool all the way ...in the lowest layer especially. So most of this looks liquid at this stage.
The NAM has handled the current event well...and the BUKFIT shows how the air dries out just as we get to freezing level concerns.
10pm tonight: note the separation of the green (moisture) and red (temperature) lines starts to take place aloft. That is the drying out taking place. At the surface, the red line is still to the right of 0. So above freezing. All rain.
By 11pm: we slide the red line at the bottom to 0 (freezing) but the upper layers dry out so much---nothing falls.
I would not rule out some light sleet or maybe 20 mins of freezing rain---but any icing would be limited to objects well off the ground.
My concern will be toward sunrise. Depending how much the roads can dry up--black ice may be a concern as we drop to near 20 degrees across the north...mid 20s for the rest of us. Use caution in the morning. I would make sure to watch Christie/Chris in the morning for the latest on that potential.
There are a couple of weak waves that try to push into the our area Monday and Tuesday. Right now---our southern counties look most at risk for any precip---but it looks so light---barely worth a mention right now. We will narrow that down more once we get closer----but a light rain/snow mix across SE sections of our viewing area is possible both days. Right now---appears quite minor.
Then the rest of the week we enjoy a west wind. This means the warm up will be modest. We should get close to 50 by the weekend.
Then, things change.
The picuture continues to get clearer and clearer with the pending Arctic plunge during this period. The Arctic front is likely to sag south over the region by Sunday. As it does so---we will be in "clipperland" with the potential for some light snow. Accumulations are possible with these---esp. along Arctic boundaries--so it will be interesting to see how that plays out.
The cold really takes hold Monday and Tuesday (22nd/23rd). GFS/EURO vary on how far south this will go...but both in good agreement that the Greak Lakes looks like ground zero for the cold with impacts being felt locally.
GFS temp departures w/o 1/21 EURO temp departure w/0 1/21
That cold shot may ease somewhat---but likely another surge on its heels to re-enforce it.
Overall---the coldest air in a few years about to impact the eastern USA---- just how cold we get remains unclear---but the risk is there for highs in the low 20s certainly. Plenty of time to fine-tune that one.