Rain will begin to overspread area tonight. It may begin as a very brief period of freezing rain. After lows around 30-32, we will rise to 34-37 by early tomorrow morning. Southeast winds will increase to 10-15 mph.
Rain looks solid & steady through morning & into the afternoon tomorrow with highs varying from 36 in the far northwest to 53 in the far southeast with warm front cutting the area in two piecies; one northwest, the other southeast.
Severe weather with a squall line of severe storms is possible in southern Indiana with highs 63-68! This squall line may get as far north as Indianapolis metro with isolated severe risk there & highs 58-61.
Our solid, steady rain will become more periodic to showery later in the day as spokes of showers & bands of rain pivot around our strong area of low pressure centered over northeastern Illinois to far northern Indiana.
This will be a windy system with persistent gusts to 30 mph at any point tomorrow-tomorrow night. HOWEVER, there will be TWO bursts of stronger wind with this system:
1. 35-40 MPH GUSTS: Working southwest to northeast through the viewing area tomorrow will be these gusts. This should pass in that direction between 10 a.m. & 2 p.m.
2. 40-50 MPH GUSTS: Working west to east over the viewing area, these should pass in the 4 p.m. to 7 p.m. timeframe.
Periodic rain/showers should go to areas of wind-driven drizzle in the evening as temperatures fall into the 34-40 range. Gusts will run generally 27-32 mph (40-50 mph gusts should exit the far eastern areas around 7 p.m.)
So, if you are headed out for New Years Eve celebrations, it looks drizzly, misty & blustery with 30s to 40 & wind chills 27-31.
Total rainfall from the system overall will run 0.75-1.50".
Drizzle should change to areas of light snow & freezing drizzle Tuesday morning after 5 a.m. That change-over should work southeastward 5 a.m. before changing area-wide by noon.
Areas of the light snow & freezing drizzle should continue through the afternoon & into the evening. Some slick spots may develop, mainly late Tuesday & into Tuesday evening.
Any of this should change to just all patchy light snow & flurries before ending Tuesday night.
Extensive icing is possible from central Michigan to far northwestern Illinois to Iowa.
Model data suggests dusting of snow in places Tuesday-Tuesday night (0.5" or less) with heavy snowfall well northwest of our area.
Trace amounts to 0.01" of freezing drizzle are possible.
It is still unclear what will transpire late week. The new data is much less aggressive with the cold. This trend permeates all model solutions & given the MJO phase, I don't doubt it. So, I increased temperatures Tuesday-Thursday & then again Friday-Saturday.
A clipper to the north & a big southern storm system need to be monitored for Thursday.
Interestingly, this storm could bring snowfall to the southern U.S., but whether it merges with our clipper & we get snow is unclear.
Or, it could be JUST the southern system that tracks farther northward & we get something out of it (snow wise), as long as it does not get mild & it becomes a rain event.
IF we would happen to get accumulating snowfall Thursday, then that would throw off the current forecast of 45-51 Saturday-Sunday. Those days would be cooler, given the snow pack.
So, there are several things up in the air with this forecast.
Canadian model has a winter snow of snow! We shall see.
This is like ranking Duke number one & all factors point to them being number one with a number one seed in the NCAA tournament & they keep loosing because they lost two star players that you did not foresee being out. I project #1 in the AP poll, but they actually drop in ranking to 20, say.
Same thing is happening with the cold & snow.
It looks like Arctic blast, then it backs off, then surge of mild weather with rain comes in. Looked like a brief surge before the bottom falls out mid-month, but the first 7 days of January looked COLD with snow & mix potential.
This 7-day forecast isn't that bad for the first week of January really. Yes, some light snow & freezing drizzle is something to watch for Tuesday, as well as potential Thursday system, but otherwise, it is pretty soft.
All the players are on the court for cold................analog data & all of the teleconnections...........EXCEPT one. It appears that the MJO is the wild card that just keeps working to keep cold & snow away.
Flare-ups of convection in the Indian Ocean to near Australia area keep us in the warm MJO phase. This phase is OUTPLAYING the cold cards now. Just look at southern Indiana's spring day tomorrow with severe weather risk 60s!
Stratospheric warming is working down in the Arctic to loosen the Polar Vortex & let the cold go south, PNA is going negative, NAO & AO is going negative.................all points to cold, cold, cold & snow. Even the El Nino Modoki is actually showing signs of beginning to weaken, so that mitigating factor may be decreasing for the winter. So, the drivers appear to be the cold drivers more & more.
Then you run into the issue of how the MJO gives you DIFFERENT weather outside of an El Nino Modoki, even if it stays in the same phases. It also gives us DIFFERENT effects in mid to late winter, compared to early winter, even if it is in the same phases.
My thoughts are...................well, my analogs tell me cold & snow, but if the models are backing off (again) for now until after mid-January, then I need to back off too. I see no reason why it will not tank to cold, cold & snow beyond mid-January & then right into February.......I say this given the cold players on the court & the dominant warm player being benched or getting injured & being off the floor in the game.
Also think of it like an NCAA bracket, if one player or team in weather is kicked off unexpectedly, despite what the past has shown, then your whole bracket is off.
MJO warm phase so strong & so long with these Indian Ocean flare-ups are messing with our bracket.
Yeah, I went for warmer, wetter burst after Christmas to around New Years in outlooks made weeks & months ago, but not waves of mild weather & rain this persistent. I am off on that.