Wednesday, December 8, 2010

Forecast for Western/Northwestern WI

Forecast problems..Really none to speak of tonight..1 to 3 inches of snow still looks like a good bet… The storm system we have been watch for the weekend will remain well South of the area, however get ready for the coldest air thus far this winter.. More on all of that later….


At 10 PM we find temps ranging from just 1 above to as warm as 10 above….Winds are calm under mostly to cloudy skies….


Tonight we find a 1028 MB high pressure system centered over Southwestern WI….We also find a 1008 MB low pressure centered just North of Northwestern MT…..High pressure will ease off to the Southeast throughout the night… Clouds have already became to increase over the FA ahead of a warm front… So temps may drop a few more degrees so still could see some below zero readings yet tonight… Winds will become South still remain on the light side….This will allow for temps temps to warm throughout the night….Tomorrow we see the low pressure system deepen to around 1000 MBS as it moves along the US/Canada border this will drag a warm front through the FA in the morning then a cold front through the FA later in the evening…. Moisture is scant with this system though there will be enough lift and forcing along the frontal boundaries to ensure light snow for my central/Central parts and Northern parts of the FA…Will keep the same thinking in the snowfall see map in the forecast below for details….There could be some freezing drizzle throughout my Southern areas and also in my Southern central areas…… This system pulls to the Northeast rather fast…Main CAA will come riding down about Friday night’s time frame..Still not as cold as what we will be dealing with…..Thursday’s temps lower to middle 20s with lows in the middle teens.. Friday highs upper teens same with Saturday… Lows Friday night lower to middle single digits….

Ok here we go trying to pin down the track of this snow storm…Can say this we won’t see any accumulating snows in my FA..
Lets look at the ECMWF model as this model seems to be having a hard time deciding what to do with the storm system OZ run had the system way South…12Z run now looks like this… Saturday we see a 1005 MB low pressure over South west IA, meantime we see another 1005 MB low pressure over Northern TX..Both lows join up in Western IL then deepens rather fast be Saturday night early Sunday down to around 995 MBS as it pushes through Northern IL..Mean while a strong high pressure system..1040 MBs drops into ND, and SD… Pressure gradients really crank up.. So this would lead to a very windy day on Sunday…. Hold on now lets look at the GFS…
GFS has a 1007 MB low pressure over the TX Panhandle…GFS dives this low into East central TX..Then moves the low Northeast to About Eastern part of TN/Western NC, and deepens the low to around 999 MBS.. From there GFS pushes it into Northern Main and deepens the low to around 970 MBS…. GFS has a much weaker high pressure system building into the area, though still strong 1036 MBS……So if GFS wins out we won’t see the very windy conditions….One thing to note this track is more South and East then it’s 06Z run… So this model is also having some issues that need to get worked out….So seems fit to run with some light snow from late Friday night into Saturday early afternoon…
One thing that does appear likely is the Arctic blast that is set to move in Saturday later afternoon, and lasting right through Tuesday…. Lows well below zero could see some -20°s in our colder spots..Highs will have a hard time making to above zero…

Will not go any further out in the forecast not till I see a better agreement in the long range models…Which hasn’t been there for the last few days….