Weather

St. Cloud, MN Weather Forecast

Friday, January 18, 2018 3:25 AM

Bob Weisman
Meteorology Professor
Saint Cloud State University
Atmospheric and Hydrologic Sciences Department

Trying to Get Clearer Picture of Sunday-Monday Major Snowstorm in (South Central and Southeast?????) Minnesota

Thaw to Continue Friday

Temperatures climbed well above freezing yesterday for the first time since the middle of last week (see 14-day graph of St. Cloud temperatures from MesoWest). Highs approached 40 degrees in St. Cloud and broke into the 40's in southwestern Minnesota (see Yesterday's High Temperature Map from NWS/SUNY-Albany), which mostly missed last Sunday's snowfall. Even the St. Cloud area lost much of its snow cover with large bare spots in town. The sunshine was dimmed a bit yesterday but some high clouds (set product to "clean IR" and frames to 54 on the Colorado State RAMMB slider satellite loop), but we still basked in the warmth.

The mildest portion of this mild air will move over Minnesota today. The pool of warm air ended up producing high temperatures in the bare ground areas of Nebraska and South Dakota (see Yesterday's High Temperature Map from NWS/SUNY-Albany). (Note that the 71 degree temperature at Rapid City Airport is most likely wrong, since other Rapid City area reports topped out in the upper 50's). We will be beginning the day with temperatures again no cooler than the middle or lower 20's (see UCAR Minnesota surface chart) and will likely see more widespread highs in the 40's this afternoon.

Not Quite as Mild Saturday

Tonight, a weak cold front will push through Minnesota, bringing slightly cooler air into Minnesota. We have a slight chance of a brief rain shower late today, then the cooler air will move in. Low temperatures won't drop that much, thanks to a decent amount of moisture near the ground due to the snow melt and also those high clouds hanging around. Lows will be in the 20's once again, which is where our average high temperatures are supposed to be. Tomorrow, we will see some sunshine filtered by the high clouds. Temperatures will be a shade cooler than today, but likely still climb into the middle 30's. Parts of southern Minnesota could again see 40's.

Potential Major Snowstorm Pushed More to Sunday Night-Monday?? With Heaviest Snow in Southern and East Central Minnesota??????

The powerful storm off the British Columbia coast (see Pacific infrared loop from Colorado State RAMSDIS) is still forecast to spin off a storm that will produce a Central US storm early next week. The actual system that will move inland is a second mid-level circulation that is pushing southeastward in the eastern Pacific about parallel to the California coast (see Pacific water vapor loop from Colorado State RAMSDIS). The computer forecasts haven't been jumping around quite as much in the past day than they had earlier in the week. There has been a small southeastward trend in the storm track, so the literal output from the computer forecasts put the swath of heaviest snow from eastern Nebraska, extreme southeastern South Dakota, and northwestern Iowa through southern Minnesota on about a Worthington-Mankato-Red Wing line. The storm is forecast to move a bit more slowly, so the heaviest snow would develop late Sunday afternoon in northeastern Nebraska and move into southwestern Minnesota Sunday evening. The heaviest snowfall would hit the Lower Minnesota River Valley and east central Minnesota from late Sunday evening and continue overnight and through the morning hours. The computer forecasts have also backed off from the ridiculous precipitation accumulations shown yesterday and the day before, so the heaviest snow band is forecast to produce on the order of 8-12 inches of snow. Some heavier amounts of 15-18 inches might be possible if a snow band gets organized across south central Minnesota Sunday afternoon, prolonging the period of accumulating snow.

However, the European computer forecast has a storm track further to the southeast and is also pushing it more southeastward. So, the storm track could move more. I am expecting more consistent performance from the computer forecasts this afternoon into tomorrow morning, since the actual storm system will move into the Southern Rockies by tomorrow morning, where it can be sampled by the entire US observation network.

For now, I would say adjust my forecast a bit and say that the southern half of Minnesota is the most likely area to see either the heaviest snowfall or be on the northern fringe of the heavy snowfall. I'd include Mankato, the Twin Cities, Hutchinson, Red Wing, Taylors Falls, Worthington and Pipestone in this zone. The Minnesota-Iowa border could be warm enough to have a wintry mix change over to significant accumulating snow, but they have a decent chance to see the heaviest snowfall. That would include Fairmont, Rochester, LaCrosse, and Albert Lea. In St. Cloud, Willmar, Little Falls, and Alexandria, we could be on the northern fringe of the major snowfall, seeing some shovelable snow with still a small chance of seeing the heaviest snowfall if the track lurches northward again. .

Note that the heaviest snowfall area will produce major travel impacts during Sunday night and Monday, since the combination of heavy snowfall rates and blowing snow will make it difficult for road crews to keep up. There will be widespread low visibility in the heavy snow band as well. The Monday morning commute could be quite a mess. There could also be more problems in the area that has mixed precipitation changing to snow, since roads will likely be covered by snow with ice lurking underneath.

Seasonable Temperatures After the Storm Eases Off

Most of the storm effects will move out of Minnesota Monday afternoon. The strong winds will keep up through Monday evening, then begin to ease off in the early morning hours of Tuesday. There isn't another slab of Greenland air directly behind this storm, so high temperatures will likely be in the 20's on Tuesday with perhaps a few teens in the heaviest snowfall areas. If we have a clear night around mid-week, we could see lows near zero or a bit below under the snow cover. In general, temperatures will remain no colder than about average into the middle of next week.

We will be closer to the border between seasonably cold air and milder air for a chunk of next week. That means at least some decent temperature swings and perhaps more consistent chances for precipitation, but there doesn't appear to be anything big into the middle of next week.

Confidence Level: "The Leaves Will Fall in My Yard"

Friday 1/19/2018: Sunshine through high clouds, breezy, and mild. A slight chance of an afternoon rain shower. High: between 40 and 45. Winds: SW 5-15 MPH. Chance of measurable precipitation: 20%

Friday Night: Partly cloudy, diminishing winds, and still mild. Low: between 20 and 25. Winds: W 5-10 MPH. Chance of measurable snowfall: 10%

Saturday 1/20/2018: Mostly cloudy, light winds, and a shade cooler. High: between 34 and 38. Winds: W 5-10 MPH. Chance of measurable snowfall: 10%

Saturday Night: Thickening clouds, breezy, and still unseasonably mild. Low: between 24 and 28. Winds: NE 8-15 MPH. Chance of measurable snowfall: 10%

Sunday 1/21/2018: Mostly cloudy with a slight chance of occasional light snow or some flurries, breezy, and colder. High: between 28 and 32. Winds: NE 5-15 MPH. Chance of measurable snowfall: 20%


Confidence Level: "The Neighbors' Leaves Will Blow into My Yard"

Sunday Night: Mostly cloudy with occasional light snow or flurries evening, becoming a steadier snow in the early morning hours. Becoming blustery in the early morning hours. Low visibility in falling and blowing snow. Low: between 24 and 28. Winds: NE 15-25 MPH. Chance of measurable snowfall: 70%

Monday 1/22/2018: Cloudy with steady snow or flurries and continued blustery. Temperatures holding in the middle to upper 20's. Winds: N 20-30 MPH with higher gusts. Chance of measurable snowfall: 50%

Monday Night: Flurries ending, perhaps some partial clearing, and turning colder. Not quite as windy after midnight. Low: between 12 and 18. Winds: NW 15-25 MPH evening, 8-15 MPH after midnight. Wind chills near zero. Chance of measurable snowfall: 60%

Tuesday 1/23/2018: Mixed clouds and sun, perhaps a flurry, much less windy, and seasonably cold. High: between 20 and 25. Winds: W 5-15 MPH. Chance of measurable snowfall: 20%


Confidence Level: "The Yard Fairy Will Secretly Rake Up All of My Leaves During the Week"

Extended: Continued average to above average temperatures through the middle of the week.

Forecast Confidence (10 - "Will more of your hair fall out, Bob?"; 0 - "Will the winning PowerBall Numbers be encoded in your lost hair, Bob?"): 7 Friday through Saturday night, 6 Sunday, 4 Sunday night through Tuesday.

Yesterday's High: 39°F; Overnight Low (through 3 AM Friday): 21°F
St. Cloud Airport Precipitation (through 3 AM Friday): None; SCSU Precipitation (through 3 AM Friday): None

January 19 Historical Data High Low
Average Temperatures 21°F 1°F
Record Temperatures 50°F (1900) 30°F (1914)
-15°F (1985) -40°F (1994)

Next Update: Saturday, January 20, 2018 8 AM (or as needed)

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Let me know what you think about this forecast and discussion by emailing SCSU meteorology professor Bob Weisman. Please note that I make the forecast, not the weather!

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