Friday, February 18, 2011

The Forecast for Western/Northwestern WI.

Forecast problems..Today winds…. Later this weekend a possible snowstorm…. Which is now looking more likely for later Saturday night through Monday morning time frame…..


970 MB low pressure is centered just to the Southwest of Hudson Bay Canada this low dragged a cold front through the FA early last evening….Brought the highest wind gust over in MN and my Central/ Eastern parts of the FA…The Central/ Eastern areas saw wind gusts around the 40 MPH while the Western areas saw wind gusts up to 30 to 30 MPH….Cold front is now entering Western NY and extends down to North Central TX… A large 1035 MB high pressure is centered up over Northwestern Canada the pressure gradients between the high and low will keep for a rather windy day across the FA…. Winds should be decreasing later today/evening… Still today we could see wind gusts up to 30 MPH…. Tonight temps will drop to around the 5 to 10° mark under partly cloudy skies… Saturday still looks to be dry…. Now let’s talk about this winter storm that looks more likely to effect the area on Sunday…..As you all know from previous forecasts some of the models changed their mind within a 6 hr time frame to bring the storm system more North…. Lets now look at some of the models and their forecasted track of the system… Looking at the 12z runs…. Let’s start off with NAM…..Later tonight NAM has a 1003 MB low pressure just off the coast of CA around the Marina area, by later Saturday morning the low is centered over Western NV around the Carson city area…By early Sunday morning NAM has the low pressure 1001 MBS centered over Central CO never the Denver area… From there NAM moves the low into Southern IA/Northern MO and deepens it to around 996 MBS from there the low is forecasted by the NAM model to push into Southern NY…. So Nam now has trended a little more South than yesterday…. This track would take the heaviest of the snow South of the FA…Looking at the GFS model at the start GFS has the same track of the low moving into CA and then into NV through Eastern CO GFS deepens the low to around 995 as it pushes into Southern NE/Northern KS…GFS tracks the low right through Central IA from there it tracks along the Southern WI/Northern IL border to PA…..This track would put the heaviest snow over Central MN and Most of my FA….. ECMWF model concurs… So most of the FA could be looking at 8 plus inches of snow by time this storm is all said and done….What is strange NAM paints out over 10 inches of snow however with the track I do think this model is over estimating snowfall this far North….However with that said GFS is painting out over 14 inches of snow for a large part of the FA…..We will see what happens…. Thinking right now is to run with 6 to 12 inches of snow just to be on the safe side….It will also depend how much warm air gets drawn into the storm system both at the SFC and the middle levels… Some areas could see rain/frz rain/mixture/ before changing over to all snow…. We will detail that tomorrow better… As of right now things could change…..

Snowfall map will be issued either later tonight or tomorrow……For the long term forecast see previous forecast below…. Will leave that ride another day or two as it seems to match well with the long term forecasting models….


TODAY..Mostly sunny, winds 15 to 25 MPH with gusts up to 30 MPH from the West/Northwest… Highs from 20 to 25.

TONIGHT…. Partly cloudy, lows from 4 to 10… Wind decreasing to calm….

SATURDAY… Partly cloudy, highs upper 20s to low 30s… East/Southeast winds 5 to 10 MPH.

SATURDAY NIGHT…. Cloudy light snow possible late, lows around 15 to 20..East/Southeast winds 5 to 10 MPH.

SUNDAY/SUNDAY NIGHT…. Cloudy snow likely highs upper 20s, lows around 15..

MONDAY… Light snow otherwise cloudy, highs around 20….

As of right now total storm accumulations 6 to 12 inches possible…. The amount may have to be adjusted either down or up….