Massive storm drives multiple warnings

We’re running out of colors on the weather maps Wednesday. This massive storm system has triggered everything from avalanche warnings in the Rockies to blizzard warnings in the Upper Midwest.

Warnings map, via National Oceanic and Atmospheric Administration

Throw in warnings for wind, flood watches and dense fog advisories and you have a map that looks a kindergarten art project. Our weather simply refuses to color between the lines this month.

Flood threat: phase 1

Our two-phase flood threat starts Wednesday. Rain on deep snowpack, frozen ground and milder temperatures combine to trigger localized street flooding.

Flood watches cover most of the Upper Midwest through Thursday.

Twin Cities National Weather Service

All that water simply has no place to go but into the low spots.

The latest Twin Cities National Weather Service situation report reflects the changing situation.

Flood warnings have already been issued for some areas. Roads were underwater and washed out from southeast Minnesota to near Eau Claire, Wis. Tuesday night’s rainfall southeast of the Twin Cities triggered this flood warning, which has since expired.

Wednesday’s additional rainfall will likely trigger additional flood warnings.

One note: Rainfall totals do not look as high to me as they did Tuesday. That could be good news.

Rainfall moves from south to north across Minnesota Wednesday. The heaviest rains favor western Minnesota.

Rainfall coverage and intensity picks up through midday hours Wednesday afternoon. A “dry slot” works into southern Minnesota Wednesday night that will taper rainfall.

Again, I’m seeing a favorable trend toward less rainfall. Especially in eastern Minnesota.

NOAA Global Forecast System model, via tropical tidbits

The system ends with a light coating of wet snow Thursday night. Here’s a wider look at model precipitation totals this week.

NOAA GFS precipitation output, via pivotal weather

Blizzard warnings

As if flooding isn’t enough of a threat this week. The cold side of this storm will bring intense blizzard conditions in the Dakotas and northwest Minnesota.

Including the cities of Cooperstown, Finley, Hope, Mayville,
Hillsboro, Hatton, Portland, Valley City, Fargo, Lisbon,
Enderlin, Gwinner, Milnor, Forman, Rutland, and Wahpeton
513 AM CDT Wed Mar 13 2019

…BLIZZARD WARNING IN EFFECT FROM 7 PM THIS EVENING TO 1 AM CDT
FRIDAY…

* WHAT…Significant blizzard conditions expected. Total snow
accumulations of 2 to 11 inches and ice accumulations of around
one tenth of an inch expected. Winds gusting as high as 60 mph.

* WHERE…Portions of southeast North Dakota.

* WHEN…From 7 PM this evening to 1 AM CDT Friday.

* ADDITIONAL DETAILS….Travel could be dangerous to impossible
at times. Widespread blowing snow could significantly reduce
visibility. The hazardous conditions could impact the Thursday
morning or evening commute. Strong winds could cause extensive
damage to trees and power lines.

Warmer days ahead

Overall temperatures look milder the next two weeks. Highs in the 40s, and even 50s become more common by late next week.

NOAA, via Weather Bell

Flooding phase 2

The warmth will trigger phase 2 of our flood threat this spring in area rivers. Smaller rivers like the Crow, west of the Twin Cities, will rise first, followed by bigger rivers like the Minnesota and Mississippi.

The Crow River is forecast to rise about 8 feet, to near (minor) flood stage by this weekend.

You can watch the progress of flood forecasts on your local river here.

Stay tuned.