13.5" snowfall in Silver Bay Sunday!
Heavy snowfall totals in northern Minnesota Sunday
Next storm takes aim at central/southern Minnesota Tuesday-Wednesday
Heavy snowfall likely for much of central Minnesota including metro!
Mixed sleet/ice/rain for southern Minnesota (significant icing possible)
1" to 2" liquid precip content by Wednesday PM?
6" to 12" widespread snowfall totals likely, with 1'+ totals possible
Next system taking shape:
It was 1 week ago that our weather pattern shifted into "active" mode. Since then 3 separate storm systems have clipped parts of Minnesota with snow.
We focused on northern Minnesota Sunday, now it looks like central and southern Minnesota, and greater Twin Cities Metro, are under the "Bull's Eye" this time.
System #4 is taking aim Tuesday & Wednesday, and it looks like a duzy.
We're still a good 24 hours away from the main body of the storm so the track may still change, but this could likely be the biggest snowfall this winter in the metro and much of central Minnesota.
Let's break down the system as it looks heading into early Monday.
A classic "Colorado Low" pressure system forming on the lee side of the Rockies in Colorado Monday. Colorado Lows tend to produce heavy snowfall totals for Minnesota, and can trigger lighting and thunder.
There are still some slight (but important) differences in track forecasts for the low pressure center.
The 0Z NAM tracks the surface low from Sioux City, IA east through northern Iowa Tuesday to La Crosse by early Wednesday.
This track would favor all snow for the metro and bring the snowfall "bull's eye" from Willmar through the Twin Cities.
The 0Z GFS favors a more northerly track along the I-90 corridor from Worthington to Rochester.
This track allows warmer air to mix into the metro, and could change snow over to a mix of sleet or ice for several hours Tuesday night-Wednesday morning. It may also allow some "dry slotting" to taper snow intensity early Wednesday. This would reduce snowfall totals in the metro and place the snow "bull's eye" north of the metro from Alexandria to St. Cloud and Mora and Siren, WI.
The European model favors the more northerly GFS track.
The GFS is faster and brings snow into the metro by just after midnight early Tuesday morning. The NAM holds off until around 6am Tuesday.
Most models end snowfall from west to east Wednesday PM. (around 3pm for the metro)
When you subtract out a period of mixed precip (midnight-6am Wednesday) and a potential "dry slot" the total duration of snowfall appears to likely be around 27 hours.
If snowfall rates average .5"/hour during the storm...that would be a good 13" of snowfall.
The models are cranking out about 1.5" of liquid precip for this event in the metro and central MN.
Some may fall as a mixed bag of ice/sleet/rain in and south of the metro. In areas that see all snow, that could produce 15" at a 10:1 snowfall:liquid ratio...which seems likely for this event.
Regardless of precip type (rain/ice/snow) that much precip will be a blessing for drought stricken areas in the storms path!
With current snow cover and the coming storm, that could be 2" of runoff for rivers & lakes this spring.
So the big question for many is..."How much will I have to shovel/drive through?"
Take a look at the differences from the late Sunday night model runs!
I still want to see Monday morning's model runs for any track shifts and see how much warm air surges north ahead of the system. But at this point here's what I expect from the weather lab.
-Widespread 6" to 12"+ snowfall totals from Alexandria through St. Cloud south into the Twin Cities metro by late Wednesday.
-There will be some 12"+ totals (as high as 18"?) somewhere between the metro and Alex-St. Cloud.
-There still is a chance for 12"+ totals in the metro, if the storm follows the NAM's "southern solution."
Wind & Blizzard Warnings!
Forget about snowfall totals for a minute. There will be enough snow and wind in western Minnesota to generate blizzard conditions Tuesday into Wednesday.
Blizzard watches/warnings will fly and travel will be downright dangerous in much of central and western Minnesota.
Stay tuned as we get a look at Monday's early model runs, and batten down the hatches for the potential for heavy snow by Tuesday!