St. Cloud, MN Weather Forecast

Thursday, October 19, 2017 8:30 AM

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

Updated for Extreme Fire Danger This Afternoon

Discover Red and Black Everywhere

As Warm, If Not Warmer, Through Tomorrow

As St. Cloud State University prepares to host hundreds of prospective college students during its Discover Red and Black Days, it will be warm enough to have extra red and black in the form of Asian beetles and box elder bugs. Yes, this is a weird way of saying that the unseasonably warm weather will continue today through Saturday.

The weak cold front went through Minnesota around midday yesterday (see 24-hour loop of NWS surface maps), but it made very little difference in central and southeastern Minnesota. Temperatures still climbed into the upper 60's and 70's (see Yesterday's High Temperature Map from NWS/SUNY-Albany). The only cooling seen was in northwestern Minnesota into North Dakota where the early cold front passing kept highs only in the 50's to low 60's.

This morning, lighter winds in the cooler air have allowed temperatures to drop back into the lower 40's with even a few 30's around (see UCAR Minnesota surface chart). However, the wind has already switched to southwest in western Minnesota and the Dakotas, once again pulling warmer air back into Minnesota. We aren't completely clear this morning, with a thin patch of high clouds (see infrared satellite loop from College of DuPage Satellite and Radar Menu). There are more impressive looking clouds streaming from Alberta and Saskatchewan towards the Dakotas and Minnesota. However, these clouds are bright white only because they are cold, high clouds. This hour's NWS aviation weather depiction shows that the bottoms of these clouds are more than 20,000 feet up (number in hundreds of feet in those Canadian provinces), making them again high, thin cirrus clouds. So, we will have plenty of sunshine once again, allowing temperatures to climb back to 70 degrees or just above this afternoon with the southwest winds picking up once again.

Extreme Fire Danger Today

That stronger south wind this afternoon has convinced the National Weather Service to issue a red flag warning, the highest category of fire danger. The combination of temperatures near 70, very low dew points and strong south winds at 10-25 MPH with gusts to 30 MPH will make any fire easy to spread. This warning covers Benson, Granite Falls, Redwood Falls, Hutchinson, Litchfield, Mankato, Fairmont, New Ulm, Mankato, Olivia, Litchfield, Willmar, Alexandria, Glenwood, Long Prairie, Morris, Little Falls, St. Cloud, and Atwater.

Tonight will be a milder night as the south wind stays up all night. Lows will likely remain in the upper 40's to lower 50's. Tomorrow will be an even windier day with a good supply of sunshine. Temperatures should climb well into the 70's with an 80 or two possible either in southern Minnesota or nearby. There may be another red flag warning out tomorrow.

Cold Front To End Extreme Warmth Saturday, But Not as Rainy as Recent Storms

Eventually, the strong south winds will pull more moist air northward, a crucial factor if we are going to get any significant rain at the end of this warm-up. The cold front that will end this really warm streak is due to come through Minnesota on Saturday. However, it's taking quite a while because the cool and dry air we had over the weekend has pushed southeastward to Florida and into the Gulf of Mexico. The UCAR hourly dew point map shows that dew points in the 50's have only returned to Oklahoma and Texas with only a few patches of 60-degree dew points in Texas. Even then, the moist air over Texas is shallower than usual, only reaching a few hundred feet up. So, you won't notice much of an increase in moisture until Friday night, when we finally receive that moister air. That means Friday night temperatures will likely remain well up in the 50's.

The late arrival of moisture and its shallow nature means that any rainfall we get late Friday night into Saturday will be significant, but nothing like the heavy rains we saw over a week ago. We might see as much as two to three tenths of an inch in showers the second half of Friday night into Saturday. There might be a thunderstorm or two, but the bulk of the tropical moisture won't get here early enough to allow any major thunderstorm problems. Temperatures will stay in the upper 50's to lower 60's Friday night, then remain in the 60's on Saturday until the cooler air blows in during the afternoon. That will knock our temperatures back into the 50's by late in the day.

We'll be in seasonably mild air for the second half of the weekend, so expect a drier Sunday with highs in the 60's.

The (Polar) Empire Strikes Back

That cold front will mark the beginning of a major pattern change. High pressure will again develop across all of western North America. That will produce a strong northwest-to-southeast flow pattern from western Canada into the Plains and the eastern half of the country. This pattern will allow the much cooler air (temperatures in the teens and 20's overnight on the NWS WPC Latest North American zoom-in surface map) to push into the Northern Plains. That cold front is due to push into Minnesota on Monday. There might be a rain shower, but the weather shake-up will bring an end to the 60-degree highs after Monday. Highs will most likely be in the 50's, if not colder on Tuesday. Average to below average temperatures will continue for much of next week.

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

Thursday 10/19/2017: Red Flag Warning noon to 7 PM. Sunshine through high clouds, breezy and still seasonably warm. High: between 68 and 73. Winds: S, increasing to 10-25 MPH. Chance of measurable rainfall: 0%

Thursday Night: Partly clear, breezy, and mild. Low: between 50 and 55. Winds: S 8-15 MPH. Chance of measurable rainfall: 10%.

Friday 10/20/2017: Mostly sunny, windy, and warmer. High: between 72 and 78 (record warm high: 81 in 1953). Winds: S 15-25 MPH. Chance of measurable rainfall: 10%

Friday Night: Increasing clouds, breezy, and becoming noticeably humid. A good chance of rain or showers after midnight. Low: between 55 and 60. Winds: S 10-25 MPH. Chance of measurable rainfall: 50%.

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

Saturday 10/21/2017: Cloudy with a good chance of rain or showers. Not quite as warm. High: between 62 and 68 in the morning, falling as the afternoon goes on. Winds: S 15-25 MPH, becoming NW 10-25 MPH in the afternoon. Chance of measurable rainfall: 50%

Saturday Night: Clearing, breezy, and cooler. Low: between 42 and 48. Winds: W 10-20 MPH evening, 5-15 MPH late. Chance of measurable rainfall: 10%.

Sunday 10/22/2017: Sunny, breezy, and not quite as warm. High: between 62 and 66. Winds: SW 10-20 MPH. Chance of measurable rainfall: 10%

Sunday Night: Partly clear and seasonably cool. Low: in the 40's. Winds: SW 5-15 MPH. Chance of measurable rainfall: 10%.

Monday 10/23/2017: Mixed clouds and sun. Maybe a rain shower. High: between 60 and 65. Winds: SW 10-20 MPH, shifting to NW late. Chance of measurable rainfall: 40%

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

Extended: Cooler weather pattern for the rest of next week??? Highs in the 50's on Tuesday??!!!

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 Thursday through Friday, 6 Friday night, 5 Saturday through Sunday, 4 Sunday night, 3 Monday.

Yesterday's High: 70°F; Overnight Low (through 7 AM): 34°F 
St. Cloud Airport Rainfall (through 7 AM Thursday): None; SCSU Precipitation (through 7 AM Thursday): None

October 19 Historical Data High Low
Average Temperatures 55°F 34°F
Record Temperatures 79°F (1947) 57°F (19201)
30°F (1930) 9°F (1972)

Next Update: Friday, October 20, 2017 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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