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Forecast models vary on rain-snow mix Halloween morning

European model shifts accumulating snow Thursday east into Wisconsin

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

It’s an interesting weather week to watch forecast models around Minnesota. We’re not yet out of the woods on the chance for snowfall on Thursday — Halloween — morning.

As we approach another record-high temperature Tuesday afternoon, the latest batch of forecast models has arrived. Most suggest a cold rain on Halloween morning that will end by late morning, but a few models still suggest it will be cold enough for a quick burst of snowfall Thursday morning.

On Monday, I posted about the European Centre for Medium-Range Weather Forecasts model that laid out the potential for significant snowfall accumulation across eastern Minnesota and western Wisconsin Thursday.

Today’s latest 12Z European model run shifts the snow zone further east into Wisconsin, but it still cranks out accumulating snow too close to home for many of us.

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

The National Oceanic and Atmospheric Administration’s Global Forecast System model paints some accumulations mainly north of the Twin Cities:

NOAA GFS snowfall output
Global Forecast System output through Thursday
NOAA, via Tropical Tidbits

NOAA’s NAM 3 km model is currently among the most aggressive on snowfall. It generates a cold pocket that changes rain to a wider snow zone across eastern Minnesota overnight into Thursday morning.

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

The NAM 3 km snowfall accumulations are on the higher end of forecast model solutions.

This map is probably extreme, but it gives you an idea of what could happen if precipitation changed to all snow for several hours Thursday morning:

NOAA NAM 3 km model snowfall output
North American Mesoscale 3 km model snowfall output through Thursday
NOAA, via Tropical Tidbits

In any case, it looks like it will dry out for Thursday night with chilly temperatures in the 30s and low 40s.

So Tuesday’s latest forecast model runs suggest we’re still not out of the woods on the possibility of some snow across eastern Minnesota and western Wisconsin Thursday morning.

We’ll continue to watch forecast models. Many forecast models suggest a cold rain on Thursday morning, but it’s much too close for comfort at this point.

Stay tuned.