Updraft® - Minnesota Weather News

Warmest air in 4 months this week, flood watch expanded

The first sign of spring in Minnesota this year? A flood watch.

The warmest air in more than four months is set to invade from the south. The last time the Twin Cities reached 48 degrees? Nov. 2. We hit 51 the day before on Nov. 1.

Temperatures soar into the 40s Tuesday across much of Minnesota. Highs approach 50 across southern Minnesota Wednesday afternoon.

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Graphic: Twin Cities NWS

Ideal flood setup

Our rapid warmup is just one of four meteorological factors that will contribute to localized flooding this week.

  • Rapid warming; highs approaching 50 degrees

  • Rain of 1 to 2 inches across Minnesota

  • Deep snowpack containing 3 to 5-plus inches of snow water equivalent (SWE) liquid water

  • Frozen ground

Those four factors mean rapid runoff that will have no place to go but the lowest spot in your neighborhood. Throw in ice-choked storm drains and you have a recipe for thousands of new instant meltwater lakes.

That's why the flood watch has been issued. And it's been expanded to include northeast Minnesota all the way up the North Shore.

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Impressive storm

Our inbound weather system is impressive as it makes landfall in the southwestern United States.

National Oceanic and Atmospheric Administration satellites capture the swirl and associated jet stream from space. She's a beauty.

NOAA's Global Forecast Sysetem model captures the potent low-pressure system moving into the Upper Midwest this week. A light icy mix precedes the first wave of rain showers Tuesday.

The bulk of rainfall arrives Wednesday into Thursday. Snow falls in the colder air on the backside in the Dakotas and northwest Minnesota.

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NOAA GFS model Tuesday into Thursday via tropical tidbits.

Around an inch of rain is likely in the Twin Cities and eastern Minnesota by Thursday. Closer to 2 inches is likely in western Minnesota. Here's the big picture covering the Upper Midwest:

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NOAA GFS precipitation output via pivotal weather.

Heavy snow northwest

The Dakotas, northwest and north-central Minnesota will be cold enough for snow. Winter storm watches are up.

Here's the view from the Grand Forks National Weather Service office.

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Image: Grand Forks NWS.

Here are the snowfall totals from NOAA's GFS model.

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GFS model projected snowfall via pivotal weather.

Spring here to stay? 

The longer range maps show milder air will persist through next week. The upper-air pattern favors milder Pacific flow late next week.

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NOAA

Some models are showing temperatures in the 50s around the weekend of March 23.

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NOAA via Weather Bell.

Stay tuned.