Thursday, November 25, 2010

The forecast for Western & Northwestern WI

 One word to sum up most of the long Thanksgiving weekend.... Cold....Winds will also be a problem for today and tonight...Then a warming trend for the end of the weekend into early next week… Also the next storm system looks to be another problem. Then another Arctic dump…. Lets hash it all out shall we….

Temps have dived into the lower to middle teens with a few stations reporting single digits…. Here at the office we have dropped to 8° while Osceola is holding at a lonely 9°… Remarkably temp at Ladysmith still holding onto the lower 20s… 22° right now, and up in Ashland the temp is a warm 28°.. Winds have been rather strong this morning ranging from 15 to 20 MPH with gusts up to 25 MPH… Superior is reporting a wind gusts of 28 MPH Eau Claire coming in at 24 MPH…. Wind have switched to the West for the most part… Windchills range from +16° to – 8°…. Skies are mostly cloudy throughout much of the FA.... However looking at the vis satellite imagery we see a very sharp clearing line running from Bayfield County South through Southeaster Washburn County through Central Barron County then down Though Southeastern 1/3 of ST. Croix County(as of 7:56 AM)…

Arctic cold front is now pushing through the FA will defined on the vis satellite imagery and SFC OBS.. Temps have been falling rather fast behind the cold front… Clear skies this morning shall fill back in as the upper level low over SD pushes Northeast…. Moisture is well East of the FA, however as the upper level pulls Northeast it should wrap some moisture back into area so clouds should increase once again and there may even be a shot at some light snow/flurries this afternoon… Best areas to see this would be in my Northern FA… Temps today won’t climb much… In fact look for falling temps in my Eastern areas as the Arctic cold front pushes through… Should see temps hold close to where they are now… May see a few degrees warmer…. Winds will remain strong today making it feel colder looking for wind chills to be from -5 to – 15 or so….. Winds could gusts as high as 25 to 28 MPH at times throughout the area…. Tonight temps are going to be a problem…. If we can get skies to clear back off and get the winds to drop off this would set the stage for temps to fall well below zero over the fresh snow pack.. For now will run with temps from -3 to +5 ..If needed the Short term update can cover the temps trend this evening….. Tomorrow I’m going to trim the temps downwards from the model guidance, as I think they are to warm calling for upper teens to lower 20s… Thinking is with a rather good snow pack and a deeper snow pack towards out Northwest, along with winds blowing over the snow pack temps won’t warm that high…. Will also depend on what happens tonight with the temps… Saturday through Sunday models been rather bullheaded about warming the temps well into the middle 20s and the lower 30s,not sure if I can buy into that just yet…. Middle 20s I could giving the strong WAA forecasted to kick in but still with a snow pack over MN, and the FA. This will help hold the SFC temps down…. Sunday night we see clouds back on the increase with our next trouble maker… Lets talk about that….

Looking at the ECMWF model…
Sunday we see a 998 MB low taken shape over NV this low races into Northern KS/Southern NE and deepens to around 991 MBS… By Monday night the low is forecasted to been in Western WI, and weakens to around 1001 MBS… As a rule a track like this would part my Northwestern FA in the snow area, however just like the last few systems… Temps upstairs are forecasted to be warm enough for a wintery mix on Monday throughout the FA… By Monday night we see temps aloft drop so mix precip would be changing over to all snow…. The track still is not set in stone, along with how fast moisture can return…. So am not going to get carried away on this just yet….

Looking at the GFS model….
Not much to say as it seems to agree with ECMWF with the track and timing of the storm system right now…. Both Models also agree on bring down another shot of Arctic air, we will have to watch this as that may be colder then the shot of cold air we are dealing with right now…..