Friday, October 19, 2018  3:40 AM

September Veers Back to November by Tomorrow

For the second time this month, and the first time since October 3, St. Cloud hit a high of 72 degrees yesterday as the warm air from the central Plains came crashing in. Unlike like Wednesday night, the combination of southwest winds (see UCAR Minnesota surface chart). and a patch of middle clouds (see Shortwave Albedo from Colorado State slider satellite menu) have kept temperatures up in the 50's all night. Some of those clouds have dropped a few rain showers over southern and central Minnesota with 0.01 inch measured at the St. Cloud Airport.

Much Colder Air Surges In on Blustery Northwest Winds Starting Late Today

However, weather systems are still moving from northwest to southeast (see Pacific water vapor loop from University of Wisconsin SSEC), so a cold front marking the western edge of this balmy air mass has been pushing southeastward through the Canadian Prairie Provinces overnight. This front will push through central Minnesota by this afternoon, ushering in another shot of cold air from north central Canada. We will take advantage of our warm start by pushing midday temperatures into the 60's once again. Sunshine will return for a while. After the cold front comes through, the patch of clouds working its way into northwestern North Dakota will spread into Minnesota. We might see a few rain showers late this afternoon or this evening. The biggest change will be very strong winds behind the front. While it will be breezy this morning with west to southwest winds at 10-25 MPH, the winds will pick up even more behind the front. We will see northwest winds at 20-35 MPH with some gusts over 40 MPH possible from late this afternoon into the evening. Winds will continue from the northwest at 15-25 MPH overnight with some gusts over 30 MPH.

Those strong winds will eventually tap the colder air, so temperatures will fall back to the middle or perhaps the lower 30's by tomorrow morning. Throw in those strong winds and wind chills will be in the 15-25 MPH range.

Need Other Side of Closet Wardrobe for Saturday

Do not dress tomorrow the same way you are dressing for today. We will see some sunshine mixed with clouds and have those northwest winds continuing at 15-25 MPH . However, high temperatures won't get much beyond 40 degrees.

The November-ish weather will continue Saturday night. There will be some high clouds, so I'm not sure we'll see the coldest night of the season so far, but lows in the middle to upper 20's are quite possible.

Actually Closer to Average Temperatures Sunday and Monday

The quick changeover of air masses will continue as Sunday's temperatures will rebound to the middle 50's, which is actually close to average for this time of year. Since the air will be dry, we will again have a shot at a Monday morning low in the 20's, but temperatures will rebound to the 50's on Monday.

The temperature roller coaster will continue with a chunk of a cooler air mass Monday night into Tuesday. Temperatures will start the day in the 20's, but rebound to about 50.

As we continue into next week, there are signs that temperatures will stop these wild swings back and forth. We could be in for more consistent average to above average highs from Wednesday through Friday, although nothing as warm as yesterday is apparent so far. The air flow will continue down the slopes of the Canadian Rockies, so rain chances will likely remain small.

Confidence Level: "The Bulb on That Hard-To-Reach Light in the Foyer Will Burn Out"

Friday 10/19/2018: Sunny and breezy in the morning, mixed sun and clouds and becoming blustery in the afternoon with a slight chance of a shower. High: between 60 and 65. Winds: SW 10-20 MPH in the morning, becoming NW 20-30 MPH with gusts over 40 MPH in the afternoon. Chance of measurable rainfall: 30%.

Friday Night: Mostly cloudy, windy, and turning colder. A chance of a light rain shower. Low: between 32 and 38. Winds: NW 15-25 MPH with gusts over 35 MPH. Wind chill between 15 and 25. Chance of measurable rainfall: 30%.

Saturday 10/20/2018: A return to November-like weather. Mixed clouds and sun, windy, and much cooler. High: between 38 and 44. Winds: NW 15-25 MPH in the morning, 10-20 MPH in the afternoon. Chance of measurable rainfall: 10%.

Saturday Night: Partly clear, diminishing wind, and colder. Low: between 25 and 30. Winds: light evening, becoming SW 5-10 MPH late. Chance of measurable snowfall: 10%.

Sunday 10/21/2018: Sunshine through high clouds, breezy, and seasonably mild. High: between 55 and 60. Winds: SW 8-15 MPH. Chance of measurable rainfall: 10%.

Confidence Level: "Every Time I Try to Put in a New Bulb, the Light Fixture Will Try to Detach From the Ceiling"

Sunday Night: Partly clear, light winds, and cool again. Low: between 26 and 34. Winds: NW 5-10 MPH. Chance of measurable snowfall: 10%.

Monday 10/22/2018: Sunny and seasonably mild. High: between 52 and 58. Winds: NW 8-15 MPH. Chance of measurable rainfall: 10%.

Confidence Level: "The Only Way I'll Be Able to Change the Bulb and Hold the Fixture in Place Will Be to Yell At It"

Monday Night: Clear and chilly. Low: between 25 and 32. Winds: NW 5-15 MPH. Chance of measurable snowfall: 10%.

Tuesday 10/23/2018: Sunny and a shade cooler. High: between 48 and 54. Winds: N 8-15 MPH. Chance of measurable rainfall: 10%.

Extended: Average to above average temperatures the second half of next week??

Forecast Confidence (10 - "The Rabbits Will Thump, Objecting to Me Yelling at the Light Bulb"; 0 - "I Will Be Hosting a DIY Show on Home Repairs"): 7 Friday through Saturday, 6 Saturday night and Sunday, 5 Sunday night and Monday, 3 Tuesday.

Yesterday's High: 72°F; Overnight Low (through 3 AM Friday): 54°F
St. Cloud Airport 24 Hour Precipitation (through 3 AM Friday): 0.01 inch; SCSU Precipitation (through 3 AM Friday): TBA

Next Update: Monday, October 22, 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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