The cold air dam has been broken in Florida!
The first Wind Chill Advisory in at least 2 winters is out for central & southern Florida.
Just Sunday, as the cold came in, we dropped to 4.7 with a wind chill down to -15, making it the coldest weather so far this winter (just barely for actual air temperature, as it was an unusually, record cold 4.8 back in mid-November).
Note how far south the 32 line gets with potential light freezing south of Fort Myers possible. 38 is possible in Miami, Homestead 37, 31-32 in parts of the Orlando & Tampa suburbs.
Interestingly, a breeze will accompany the cold. This is strong advection cold being funneled by Arctic high to the northeast.
Usually you get such a cold night with a calm wind, high pressure & strong radiational cooling. This is a gusty cold wave with a lack of frost, but pretty widespread freezing. This is the coldest air into central & southern Florida in several years.
Winds will bring unusually-low wind chills of 20-25 tonight to central & southern Florida.
The large area of stratocumulus & stratus in the Gulf, all the way to southern & eastern Mexico is a testament to the extent of it over a very warm Gulf of Mexico.
Here, after lows of 9 to 25 this morning, depending on how much cloud cover you had (13 WLFI ob site, Purdue Airport & the Purdue Ag Farm), we moderated to day to 30-34 with a lack of wind & just areas of stratocumulus clouds around.
Looks like precipitation is coming in earlier.
Trend is for all snow to move in Thursday morning..................to possibly midday.
Wet, gloppy, slushy snow may mix with a bit of rain in the southeastern half Thursday PM, then be all snow again area-wide Thursday night to Friday morning.
Temperatures will drop to 30-32 Wednesday night & hover at 32-35 Thursday, it appears.
Low in Iowa & Illinois will transfer energy to newly-develop low in southeastern Missouri as 90-knot upper jet streak pivots through the mid-Mississippi & Tennessee Valleys.
This is highly-preliminary & we will need to monitor the storm track of both lows, especially the new one that develops southwest of our area (snowfall amounts may be increase or decreased........small bits or large amounts).
Given marginal temperatures, snow may have trouble sticking well.
Model data has a total of 1-3" over the area by Friday morning.
There is a trend to change the snow to rain for a while Friday late morning to midday (temperatures 34-36), then, with dynamic cooling, go back to snow (temperatures around 32).
As the low deepens, there is a sign of potential heavier snowfall with strong gusty winds.
Below, the NAM does an interesting thing with that strengthening low.
It wraps it up near our area with a 4-5 mb surface pressure drop in a few hours with gusty north to northwest winds developing.
It also has quite a heavy, wind-driven, wet, gloppy, plastery, sticky snow falling Friday afternoon & into Friday night with temperatures 31-32.
NAM brings up to 5" of new snow (after earlier snow melts with the rain some) in our western counties & lesser 1-4" amounts as you move eastward.
Track of this strong low pressure that develops will be key to how much snowfall we receive. With this NAM track, up to 8" of wet snow are forecast Friday PM-Friday night. If this remains & track changes, our risk of a winter storm with heavy snowfall will go up.
With all the model noise several things can be gleaned:
1. A couple waves of at least minor accumulating snowfall are possible: Thursday-Thursday night & late Friday-Friday night
2. A period of rain or rain/snow mix is possible between the two rounds of snow, causing the first round to melt.
3. There is uncertainty on solid, confident, exact snowfall amounts.
Some scattered snow showers & blustery conditions are likely Saturday, followed by a few isolated flurries & snow showers Sunday.
Another storm system of rain/snow to rain to snow & gusty winds is likely mid to late next week.
Potential is there for accumulation in the last quarter of the storm. The strongest winds look to occur with the snowfall.
If the system tracks a bit farther to the south, much longer duration or even all snow could occur.
Rain to snow is possible around February 2 & snow around February 4, followed by a shot of bitterly cold air.
Surge of nasty cold will be on the move southward with wind chills below -50 in parts of northern Minnesota.
Plenty of cold bouts upstream. Still plenty of winter to get through.
Below zero temperatures still possible. -20? That was an analog trend for this winter on a couple of occasions with extremes of warmth, cold, wind, flooding, ice jamming & snow (70-degree fluctuations).
We will see how it shakes out, but cold lobes ahead.