Updraft® - Minnesota Weather News

Halloween snow: Several inches likely Thursday north, west of the Twin Cities

Rain to heavy wind-driven snow likely in central, NE Minnesota; Twin Cities flakes possible

NOAA NAM 3 km model
North American Mesoscale 3 km model between 1 p.m. Wednesday and 1 p.m. Thursday
National Oceanic and Atmospheric Admininstration, via Tropical Tidbits

Weather trick-or-treat?

The weather maps are gathering around a forecast of rain to wind-driven snow for parts of Minnesota on Halloween. Forecast models seem to be gelling around a relatively narrow band of heavy snow setting up from central into northeastern Minnesota Thursday morning through midday.

A winter storm watch is posted for much of northeastern Minnesota, including the Duluth area. I expect they will upgrade to a winter storm warning later this afternoon based on the midday forecast models runs.

Winter storm watch
Winter storm watch Thursday
Duluth National Weather Service office

URGENT - WINTER WEATHER MESSAGE National Weather Service Duluth MN

329 AM CDT Wed Oct 30 2024 ...EARLY SEASON ACCUMULATING SNOWFALL FOR HALLOWEEN...

Southern Lake-South Aitkin-Carlton and South St. Louis-Pine- Including the cities of Aitkin, Hinckley, Two Harbors, Pine City, Silver Bay, and Duluth

329 AM CDT Wed Oct 30 2024 ...WINTER STORM WATCH IN EFFECT FROM THURSDAY MORNING THROUGH THURSDAY AFTERNOON...

* WHAT...Heavy snow possible. Total snow accumulations between 2 and 6 inches, with locally higher amounts possible. Winds could gust as high as 30 mph.

* WHERE...Pine, South Aitkin, Carlton and South St. Louis, and Southern Lake Counties. This includes the Tribal Lands of the Fond du Lac Band and the Mille Lacs Band, Hinckley, Lena Lake and, East Lake areas.

* WHEN...From Thursday morning through Thursday afternoon.

* IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact the Thursday morning commute and early portion of the evening commute.

* ADDITIONAL DETAILS...While snow will be primarily falling on warm ground surfaces during the daytime hours, forecast snowfall rates of around 1 inch per hour will still lead to accumulating snowfall during the morning commute, while rates taper off by mid to late afternoon.

Rain and thunder to snow

Our inbound weather system will generate scattered thunderstorms Wednesday afternoon across southeastern Minnesota.

Rain and thunder will spread northward toward the Twin Cities after midnight. Then, as cold air filters into the system, rain will change to snow Thursday morning. A band of heavy snow will likely set up west and north of the Twin Cities.

The National Oceanic and Atmospheric Administration’s NAM 3 km model shows the trend. The forecast model loop below runs between 1 p.m. Wednesday and 1 p.m. Thursday.

NOAA NAM 3 km model
North American Mesoscale 3 km model between 1 p.m. Wednesday and 1 p.m. Thursday
NOAA, via Tropical Tidbits

Several forecast models put the Twin Cities on the southern edge of the snow zone. Thursday's most favored area for sloppy snowfall accumulations runs from just west and north of the Twin Cities through Duluth.

Here’s the European Centre for Medium-Range Weather Forecasts model snowfall output:

European model (ECMWF) snowfall output
Snowfall output forecast Thursday
European Centre for Medium-Range Weather Forecasts, via Pivotal Weather

Here’s NOAA’s Global Forecast System model snowfall output:

NOAA GFS snowfall output
Global Forecast System snowfall output Thursday
NOAA, via Pivotal Weather

This will be wind-driven snow with accumulation rates of an inch per hour possible in the heavy snow zone on Thursday. Wind gusts could reach 30 mph.

Wind gusts
Wind gust forecast for 10 a.m. Thursday
NOAA

Temperatures Thursday will hover in the low 40s, with 30s northeast.

Forecast high temperatures Thursday
Forecast high temperatures Thursday
NOAA

This is not your daddy’s Halloween megastorm, but it will bring significant wintry weather conditions to much of central and northeastern Minnesota on Thursday.

Most of the precipitation should ease out of Minnesota by trick-or-treat time Thursday evening.