Tuesday, December 7, 2010

Forecast for Western/Northwestern WI/added snowfall map

Forecast headaches…. A storm system that could bring accumulating snows close to if not over the FA for the upcoming weekend…. Snow is also possible for Thursday/Thursday night…Slight warming trend before the Arctic flood gates open back up… This will allow for the coldest air thus far this winter…

As of the 10 AM hr we see temps in the lower single digits to the upper single digits. Skies for the most part are Sunny to partly cloudy with some areas of snow flurries… Winds from the North/Northwest around 3 to 9 MPH…

Don’t be alarmed that big bright yellow thing in the sky is only the sun, bests better enjoy it today and tomorrow as it won’t last long as we got to weather features we need to talk about..First one is cut and dry. The second one is not so easy…. For today through Wednesday look for partly sunny to mostly sunny skies temps won’t be going much higher than they are now.. Upper single digits to lower teens should work rather well… Tonight temps will depend on if clouds over take the FA once again is so temps should stay above zero, if not temps will fall to below zero once again… Wednesday temps warm into the upper teens as WAA slowly kick in ahead of a weak storm system.. 1000 MB low pressure is forecasted to move along the US/Canada border Thursday through Thursday night this system has little moisture to work with, however enough lifted to cause 1 to 3 inches of snow for my Central/Central and Northern areas… While them Southern Central and Southern areas may see some freezing drizzle and light snow… Little to no accumulations are expected in those areas….Best chance at seeing 1 to 3 inches of snow will be North of a Balsam Lake, Barron, and Ladysmith… Points South of that line less than 1 inch….

Now on to our problem system….Looking at the ECMWF model first Upper level low that has been locked in place for an extended period of time over the Northeastern CONUS is forecasted to left Northeast… This will allow for a few problems… 1st off a 100 MB low pressure system is forecasted to form over Western NE on Friday/Friday night… This low is then forecasted to lift Northeast Southern WI/Northern IL on Saturday as it does its forecasted to deepen to around 996 MBS… System will has moisture to work with as the GOM opens up… If this track plays out my Central and Southern areas could see accumulating snows…However not only the track will play a role the push of Arctic air behind Thursday/Thursday nights system will also be a key factor..If the push comes in faster this could push the storm system well to the South….Lets look at the GFS model… GFS has the system forming in Northeast CO about 1008 MBS then GFA pushes this system into Southern/Central MO and deepens it to 998 MBS Then GFS moves the system Northeast along the Eastern Coastline… GFS has the Arctic air pushing into the FA sooner than ECWMF… GFS has a 1038 MB high pressure building into the area for the weekend.. So if GFS is right we won’t see much in the way of snowfall throughout the FA also less winds for the FA…….Looking at the GEM-GLB model…This model has the storm system tracking South of the area through Central IL… This will keep the snowfall still South of the FA..What is interesting is that the UKMET model agrees with the GFS on the track of the system…Though somewhat weaker until the system moves into the Northeastern States….. One thing that will save this forecast from busting is time, has we have time to watch this still.. So will not pull out the big guns just yet, will save that for Thursday’s update… One thing that is a giving on all models is next week the Arctic air will be in place… Lows could fall into the teens below zero if not twenties below zero for some areas, with highs either side of zero…..
Below is our snowfall map valid from Thursday through Thursday night.