Updraft® - Minnesota Weather News

Tracking two likely snowmakers for Minnesota

Firat system arrives Thursday. Second system could be stronger Sunday and Monday

Snow stakes
Snow stakes along the Weather Lab driveway on Tuesday.
Paul Huttner | MPR News

The snow stakes marking the Weather Lab driveway still stand at the ready. They’ve been under-utilized in this paltry snow season that has produced just 14.3 inches of snow at MSP Airport. It looks like they’ll finally be called to action over the next week.

Our normal season snowfall in the Twin Cities is 51.2 inches. Some forecast models suggest we could double our season snowfall so far in the next week.

I’m still skeptical of some of the epic snowfall total forecast models crank out for Sunday and Monday. But if the storm track happens, and the deep Gulf of Mexico moisture fetch all falls as snow, we could be looking at some ridiculous snowfall totals early next week.

Calm Wednesday

Wednesday brings the calm before the storms. Bright sunshine and a blue sky will look gorgeous. But it will be 20 degrees colder than Tuesday when we reached 51 degrees in the Twin Cities.

Forecast high temperatures Wednesday
Forecast high temperatures Wednesday.
NOAA

So far this March is running 11.5 degrees warmer than normal in the Twin Cities.

Thursday night snow

We’re still on track for snow developing in western Minnesota Thursday, then pushing into the greater Twin Cities area by Thursday late afternoon or evening. Most of Thursday’s afternoon rush hour should be dry. But Friday morning’s commute looks challenging, to say the least.

NOAA’s latest 18Z NAM 3 km resolution model shows snow developing in western Minnesota by 4 p.m. and spreading eastward along the I-94 corridor into Thursday night. The loop below ends at 1 a.m. Friday.

NOAA NAM 3 km model
NOAA NAM 3 km model between 4 p.m. Thursday and 1 a.m. Friday.
NOAA via tropical tidbits

It looks like the heaviest snow with this system will fall around and after midnight. NOAA’s updated digital snowfall map Tuesday afternoon shows a swath of 3 to 5 inches of snow along and either side of the I-94 corridor by Friday morning.

Snowfall projection for Minnesota
Snowfall projection for Minnesota.
NOAA

I had come up with a forecast of 2 to 5 inches of snow along this zone earlier Tuesday so this looks reasonable to me pending any forecast model changes Wednesday. We still have about 48 hours before the snow flies in the Twin Cities on Thursday.

Bigger storm Sunday and Monday?

The system on the weather maps Sunday and Monday still has the potential to be much bigger. The second system has a lot more going for it in terms of moisture feed and duration. It essentially looks like a deep Colorado low with a prolific Gulf of Mexico moisture feed.

If it ends up tracking close to the current model forecasts, it’s looking likely to produce heavy snow Sunday. The big question appears to be the temperature profile and the location of the rain-snow line Sunday night and Monday.

NOAA’s latest 18Z GFS forecast models brings the rain-snow line right over the Twin Cities on Monday. The loop below runs between 7 a.m. Sunday and 7 p.m. Monday.

NOAA GFS model 2
NOAA GFS model between 7 a.m. Sunday and 7 p.m. Monday.
NOAA via tropical tidbits

Where snow changes to rain, that will reduce snowfall totals. In areas where precipitation type manages to remain as heavy snow, we could see some heavy to potentially epic snowfall totals Sunday through Monday.

Stay tuned.