Mild start to the week; snow potential Wednesday and Thursday

Some Minnesotans are waking up to dense fog this Sunday.

The National Weather Service has a dense fog advisory in effect for much of southern Minnesota until noon Sunday:

rt1217msp2
NWS Twin Cities

Details of the advisory:

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URGENT - WEATHER MESSAGE

National Weather Service Twin Cities/Chanhassen MN

651 AM CST Sun Dec 17 2017

MNZ082>085-091>093-171800-

/O.CON.KMPX.FG.Y.0015.000000T0000Z-171217T1800Z/

Watonwan-Blue Earth-Waseca-Steele-Martin-Faribault-Freeborn-

Including the cities of St James, Mankato, Waseca, Owatonna,

Fairmont, Blue Earth, and Albert Lea

651 AM CST Sun Dec 17 2017

...DENSE FOG ADVISORY REMAINS IN EFFECT UNTIL NOON CST TODAY...

* VISIBILITY...Visibilities across western Minnesota will

continue to drop tonight, with widespread visibilities of a

quarter mile or less expected by the morning.

* IMPACTS...Limited visibilities will make travel difficult.

* ADDITION IMPACTS...With temperatures below freezing, a few

slick spots will be possible, especially on bridges.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Dense Fog Advisory means visibilities will frequently be

reduced to less than one quarter mile. If driving...slow down...

use your headlights...and leave plenty of distance ahead of you.

Patchy fog is also possible elsewhere in Minnesota, including the Twin Cities metro area, this Sunday morning.

Temperature trends

Most of Minnesota will see high temps in the upper 20s to lower 30s Sunday afternoon.

Southwestern Minnesota could see some mid to upper 30s.

Monday's highs will feature 40s in southwestern Minnesota, and 30s elsewhere:

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The Twin Cities metro area will probably top out in the upper 30s on Monday, which is well above our average December 18 high temp of 26 degrees.

Southern and central Minnesota will see highs in the 30s on Tuesday:

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Twin Cities highs are expected to be in the lower 30s Wednesday, then drop to the 20s on Thursday.

Highs in the teens are expected Friday through Sunday in the metro area.

Christmas chill

The Twin Cities metro area could see Christmas Eve highs in the lower teens, with single digit high temps on Christmas Day.

The coldest official Twin Cities high temperature in recent memory was in 1996, when the "high" temp was nine degrees below zero!

Snow potential

A few stray snow showers or flurries are possible in Minnesota and Wisconsin this Sunday, and some spots could see a bit of mist or patchy freezing mist.

Periods of snow are a good bet in about the northern third of Minnesota Monday afternoon and Monday evening.

Our attention then turns to Wednesday and Thursday.

Central and northern Minnesota could get the initial batch of snow, Wednesday and Wednesday night.

The best chance of accumulating snow in the Twin Cities and southern Minnesota would be Thursday and Thursday night.

Here's an overview, from the NWS Twin Cities office:

rt1217snow2
NWS Twin Cities

The National Oceanic and Atmospheric Administration’s Global Forecast System model shows the potential snow pattern Wednesday through Friday:

rt1217rad
NOAA GFS model precipitation rate Wednesday through Thursday, via tropical tidbits

The color chart to the right of the loop refers to the precipitation rate (mm per hour), and not to the amount of snow.

Several inches of snow are possible, so check forecast updates as we get closer to Wednesday and Thursday.

Forecast models do not agree on the timing of the snow and the amount of snow, but the situation should become clearer as we get closer to Wednesday.

Programming note

You can hear my live weather updates on Minnesota Public Radio at 7:49 a.m. Thursdays and Fridays, and at 7:35 a.m., 9:35 a.m. and 4:35 p.m. each Saturday and Sunday.