***MAJOR WINTER STORM***

 

A major winter storm is on track to slam the forecast area....A band of heavy snow will fall from Southwestern MN up through Northwestern WI...Meanwhile a band of freezing rain will fall from Southeastern MN into parts of Southwestern WI....Just expecting mainly all rain in Southern WI....Yesterday we were concerned about about how much warm air would be around before the CAA kicked in...That no longer looks to be a problem for much of the FA....Still my Southern areas will see more of a mixed of precip....We were also concerned about the drier air that is flowing into the FA....This won't be a factor anymore, but will help boost the snowfall rates as it won't be as strong, and the system will over come the drier air much faster...The somewhat drier air will enhance the lift....We should see another round of thunderstorms with heavy snow, or what we like to call thundersnow.....The only adjustments need to the forecast was to delay the start of the precip....Start it later tonight....The other adjustment that was needed was to take out the sleet wording in my Central and Northern areas....

This major winter storm will have major impacts on travel starting later tonight and lasting through tomorrow....Don't think blowing and drifting snow will be that much of a problem, as it looks like a heavy wet snow, however if we can keep some more drier air around and cool off the middle and lower levels of the atmosphere then we could see near whiteout conditions and blizzard conditions from blowing and drifting snow, along with the heavy snow that is falling.....The way everything is shaping up this looks to be the biggest winter storm that we have seen this winter 2012/2013....For storm totals see map below....

This could be a very dangerous storm....If you must travel from tonight and tomorrow, let someone know your planned route time of departure and estimated time of arrival..Carry a winter safety survival kit in your vehicle, if you become stuck remain with your vehicle and call for help...Best thing one can do is delay your travel plans...

So how much snow are we forecasting...Here is the map....

 

 

 

Forecast problems, there are many with this possible winter storm.....1 track of the low pressure....2. How much dry air will work in from the Northeast...3. Will this system draw up warmer air, or will the profiles cool off enough for more snow. 4. Will the forecasted severe thunderstorms rob a lot of moisture from flowing this far North.....Also this storm will come in waves if all plays out right.....So lets try to hash this out the best we can.....Notice this forecast is subject to change tonight or tomorrow morning....The forecast discussion will only talk about the short term...Not worried about the long term, as no big warm-ups are seeing.....

***CURRENT CONDITIONS***

Skies across the area are cloudy, winds are from the North/Northeast from 8 to 14 MPH with some gust up to 23 MPH.....Light rain is also falling across parts of the areas...Dewpoints range from the lower to middle 30s......

***FORECAST DISCUSSION (TODAY THROUGH FRIDAY)

A late winter major/early spring winter storm is effecting a large part of the Country, from parts of the Northern Plains into the Southern Plains...This storms has it all, Severe thunderstorms to snow...Looking at the WV satellite loop we can clearly see the center of this storm in the four corners area..Another are of low pressure forming over KS, a little harder to see but it is there.....Looking at the NAM model it shows this area of 995 low pressure in the South Central part of NM... So that as the center of low a little too far South then what is seen on the WV imagery...NAM throws this area of low pressure into far Southern TX, but spins up another area of low pressure over KS then pushes that on into Northern MO, then pushes the low into the windy city, then into the Northern OH, Meanwhile a large 1034 MB high pressure system over Hudson Bay is trying to kick dry air South into the area....Time to see what GFS model shows us...GFS 12z run...The Analysis chart show the low right were it should be at...Also it shows a 1038 MB high pressure center over MT reaching up towards Hudson Bay...We do see this model also runs the low into Southern TX, and also form another one over KS GFS takes the KS low on the same track as the NAM model....Lets take a look at the ECMWF model.....Shows about the same as NAM/GFS....Only thing different is the track of the low.....The EC takes the low out of KS then moves it Northeast towards Southwestern WI, then into Northern part of MI....All model pointing at severe thunderstorms down South...Just how much will this effect our FA.....Could be a lot, if thunderstorms are ongoing this will allow for moisture flowing this far North to be less.....Not only that if we get more drier air flowing into our FA from the Northeast this will also play havoc on the precip amounts, as the moisture will go into saturation..The other problem will be, can the Colum cool fast enough for more snow, than a wintery mix...On top of that the storm track is not even close to be set in stone, as we have seen the past few days...One day its South the next run it North, the run after that is back South, now its back North.....So it is a very compacted forecast still.....

So far now the best way to run is to blend all the models and their members along with the ensemble members together to come up with this forecast.....

We will run with a track from SW KS into Northern IL then into Southern MI....We will bank on the drier air from the Northeast to become saturated with this first wave pushing into the area now, and keep the atmosphere saturated in between breaks of the precip....The hardest part now is to figure out how much moisture flowing Northwards will be robbed by the severe thunderstorms down South....For now with blending the models....we should have enough moisture making into the FA.....We should see enough cooling as profiles suggest to switch from a wintery mix on Wednesday to all snow by Wednesday night....If this indeed does happen we should see around 4 to 6 inches of snow throughout my Central and Northern areas, while 2 to 4 inches of snow in parts of my Southern areas, with lesser amounts in my far Southern areas....Now if we can get CAA sooner like on Wednesday morning, we could end up with more snow throughout my Central and Northern areas.....My far Southern areas will still see a wintery mix and they will remain close to rain/snow line....

Today.... Look for a few areas of rain, main areas will be in my Southern areas.Though we will still see rain in my Northern areas..Highs for today should be in the middle 30s with some upper 30s.

Tonight....Snow/sleet in my Central and Northern areas with rain mixing with some snow/sleet in my Southern areas, all rain in my far Southern areas.... Lows tonight upper 20s to lower to middle 30s Far Southern areas...

Tomorrow....Sleet/snow central/Northern areas....Rain in my Southern areas....Highs middle 30s to upper 30s lower 40s Southern areas....

Tomorrow Night.... Sleet/snow becoming all snow in my Central and Northern areas, snow could be heavy at times winter mix in my Southern areas, with all rain possibly mix with some sleet/snow in my far Southern areas...

Thursday....Snow snow could be heavy at times in my Central and Northern areas, maybe into my Northern Southern areas....Wintery mix in my far Southern areas....

Total snow amounts from the storm 4 to 6 inches Central/Northern areas....Could see some local 8 inches reports.....2 to 4 inches of snow in my Southern areas, with maybe 1 an inch or two in my far Southern areas.....

Notice short term forecasts will handle it from here on out, so any updated will be found there......