Forecast model disparity continues, but confidence is growing for a major winter storm to take aim at Minnesota, the eastern Dakotas and northwest Wisconsin.
Paul's been talking about the model differences on the track of the low pressure that will determine the locaton in the upper Midwest that is likely to be buried in heavy snow Saturday night and Sunday.
Twenty years ago I would have been more confident about snow in east central Minnesota, but evidence of decadal warming says not so fast. It appears that relatively mild air is forecast to push as far north as the Twin Cities on Sunday morning and produce a wintry mix.
The National Weather Service has already hoisted a variety of Winter Storm Watches for Minnesota and the eastern Dakotas.
As travel from New York City to Boston is brought to a standstill in the next 36 hours, our focus is on the developing storm in the Four Corners area of the southwest US.
Enhanced clouds/colder cloud tops indicated in blue.
I''ll toss out this text issued out of the Boston NWS Office this morning to give you an idea what is ahead for the folks in the Northeast. Statement issued at 439 a.m. EST.
* ACCUMULATIONS...SNOW ACCUMULATION OF MORE THAN 2 FEET.
* TIMING...LIGHT SNOW WILL DEVELOP BY THIS MORNING...BECOMING
HEAVY LATE IN THE DAY INTO THE EVENING COMMUTE. THE HEAVIEST
SNOW...ESPECIALLY FOCUSED ALONG THE I-95 CORRIDOR... WILL FALL
TONIGHT INTO SATURDAY.
* IMPACTS...BLIZZARD CONDITIONS AND DANGEROUS TRAVEL. WHITEOUT
CONDITIONS ARE ANTICIPATED AS ROADS BECOME SNOW COVERED BY THIS
EVENINGS COMMUTE. STRONG NORTH-NORTHEAST WINDS ARE ANTICIPATED
WITH GUSTS UP TO AROUND 60 MPH...RESULTING IN BLOWING AND
DRIFTING OF SNOW. DAMAGE TO TREES AND STRUCTURES ALONG WITH
SCATTERED POWER OUTAGES ARE ANTICIPATED.
* WINDS...NORTHEAST 30 TO 40 MPH WITH GUSTS UP TO 70 MPH.
The European Model continues to favor a track that has the highest potential to keep the precipitation snow or a snow/sleet and rain mix.
I examined the vertical profile from the GFS model forecast for Sunday evening and it predicts a cold rain or a wintry mix for the Twin Cities. You'll just have to stay tuned for updates.11 Comments)
It's tempting to start tossing out snowfall predictions with the weather system forecast to arrive in the upper Midwest Saturday night. Not a single snow flake has yet to form to our southwest, thus I'll stall on predicting snow amounts for a specific location.
There is no reason, at this time, to make adjustments to the forecast reasoning that was posted this morning. The latest model runs still suggest the best chance for the highest snowfall totals to be northwest of the Twin Cities.
The model ensemble tracks for the center of the surface low are clustering in southern Minnesota on Sunday. Heaviest snow most often falls to the north and northwest of the track of the surface low. Temperatures in southeast Minnesota are likely to reach the lower 30s on Sunday. Precipitation could fall as a cold rain in Rochester.
Forecasters might be weighing the more southerly track of the European model by placing the red triangle in Iowa, well south of the ensemble output for Sunday. If the European model verifies, the Twin Cities could experience mostly snow, versus a wintry mix.
The National Weather Service has posted a Winter Storm Watch for the Dakotas through much of Minnesota in western Wisconsin for Sunday. Some locations in western Minnesota could experience near blizzard conditions.
Here's the latest thinking on the probability of snow accumulating 6 inches or more on Saturday night and Sunday from NOAA NCEP/HPC issued Friday afternoon:
Quiet weather is in store through Saturday morning. Travel is likely to become hazardous after dark on Saturday.
All systems are still "go" for a major winter storm this weekend in a big swath of Minnesota.
As winter storm and Blizzard watches evolve into warnings this weekend, what seems clear is that the heaviest part of the storm will produce some impressive 6" to 12"+ snowfall totals by Monday AM.
I had hoped Friday's model runs would provide greater clarity on the eventual storm track this weekend. That was wishful thinking.
The latest trends on our weekend storm revolve around one major factor for the metro. The storm track. North or south?
In this Updraft update, I lay out the most likely heavy snow band that will ride the northwest edge of the Twin Cities, and talk about what happens to metro snowfall totals if the "southern solution" wins the day.
Either way, batten down the hatches. After a glorious winter Saturday, a major winter storm is on the way by Sunday that will affect travel conditions in most of Minnesota.
It's easy to shrink from the difficulty of "making the call" on an incoming storm.
To be sure...this storm is a bear. A big angry bear...and I use that term kindly. I may be as wrong as the next (weather) guy/gal. Still, you'll get my best read on the storm..and my commitment on what I think the most likely scenario is today... for better or worse below.
Take your best shot at me Monday morning if you like, but this is the best I can do reading this unwieldy set of models right now.
And yes...there's a big storm out east. But we are Minnesota Public Radio Radio. And... all weather is "local." So, here's my best take at this point on what will happen in your backyard this weekend.
There are usually differences in the suite of computer models we look at every day. Just not this much.
Friday's late trends do show some movement on NOAA's models that brings them closer to the "southern solution" favored all week by the "Euro."
Why is that important for the Twin Cities?
A more southerly storm track means a colder atmosphere over most of the metro. That means less mixed precip, and more snow.
At this point I am still leaning toward the Euro for this weekend's system.
We still have the Friday night and Saturday morning model runs before the snow flies, but here's my latest thinking on this weekend's weather system.
A "Colorado Low" that will likely track through Nebraska, Iowa, southeast Minnesota to near Green Bay by Monday.
Southerly wind flow feeding into the system will inject plenty of moisture from the Gulf of Mexico. This will be a much "wetter" storm than our recent snows.
Snow will break out in southwest Minnesota Saturday night, and move into the Twin Cities after midnight. Precip will continue on and off through Monday AM.
Temperature profile and precip type:
At this point I have high confidence that the heaviest snow band will lay out northwest of the metro.
A wide swath of 6" to 12"+ snowfall is likely to lay out from Aberdeen to Ortonville, Willmar, Alex, St. Cloud, Brainerd, Hinckley and Duluth.
This is likely the "sweet spot" for all snow and heavy snow with this system.
Metro likely on the edge of heavy snow:
For the metro, it's all about the storm track.
I'm encouraged that NOAA's GFS has made small, but reluctant progress in shifting it's track south closer to the Euro.
Friday afternoon's NAM & GFS output fell into the 5" to 6" range at MSP Airport.
If the Euro is right, the "rain/snow line" will stay just south of the metro, meaning mostly snow for the greater Twin Cities...and potentially heavier totals creeping into the metro from the northwest.
Either way, there will probably be a fairly large "snow gradient"...a range of snowfall from SE to NW across the metro. Rogers will likely be shoveling & plowing more snow than Hastings by Monday morning.
My best read on an early forecast for metro snowfall is for a range for the Twin Cities ranging from 3" (SE) to 8" (NW).
If the Euro track verifies and the metro remains all snow, I could see the heavy 6" to 12" creeping into the metro from the northwest.
Bottom Line: Expect snow and mixed precip to break out in southwest Minnesota Saturday evening, and move into the metro after midnight. Travel will be impacted in most of Minnesota Sunday, including I-94 between the metro and Fargo, and I-35 north to Duluth.
Craig Edwards will be looking at the latest model runs overnight & Saturday. I'll jump back in Sunday PM as the storm reaches peak.