Friday, September 23, 2016 3:46 AM
Prepared by Bob Weisman
Professor of Earth and Atmospheric Sciences
Saint Cloud State University
Earth and Atmospheric Sciences Department
Saint Cloud and Vicinity Forecast
It Is Easy Being Green...Just Keep Raining
Rain Finally Moves Out of Minnesota...For Now
After Wednesday's deluge (with 8-10 inches in Maple Grove and over 10 inches in Waseca according to the National Weather Service map of rainfall during September 15-22), the showers and thunderstorms finally wound down in southern Minnesota by late morning. The old rain pushed the front southward into Iowa (see 24-hour loop of NWS WPC surface analysis), so the new storms that developed last night stayed in northeastern Iowa (see infrared loop from College
of DuPage Satellite and Radar Menu), pushing eastward along the Wisconsin-Illinois border (see NWS
Upper Mississippi Valley radar loop). The storms are still spending a long period of time in the same spot, so there are flash flood warnings in northeastern Iowa.
Storms Return Late Today, Tonight
However, the rain won't stay to our south for long. The main storm, now over Nevada (see water vapor loop from College
of DuPage Satellite and Radar Menu), still has to come through Minnesota and may not happen until Tuesday or Wednesday of next week. Today, the increasing southerly flow is already setting off some showers from Montana into North Dakota (see NWS
Upper Mississippi Valley radar loop). The deeper moisture in southern Iowa and Nebraska will get drawn northward this afternoon, so showers and thunderstorms will break out ahead of the warm front late this afternoon into the evening. The rainfall totals will be less than on Wednesday night.
We will have a lot of clouds hanging around today, so temperatures will stay in the 60's today.
On Saturday, the warm front will push into northern Minnesota, so we will break out into the warm and humid air. We could actually see some sunshine tomorrow, pushing highs into the 70's with oppressive humidity. By late in the day, however, the cold front will push into the eastern Dakotas, triggering more widespread showers and thunderstorms from late tomorrow afternoon through much of tomorrow night. Hopefully, these storms will move along enough to keep the rainfall out of the huge amounts seen earlier in the week. But, any additional rain over the areas with the most rainfall this week will aggravate the flooding conditions.
Low Hangs Around Through Sunday (Monday? Tuesday??)
By Sunday, the cold front will have passed, but the upper-level low will be in the Dakotas. The biggest uncertainty is how quickly this low gets out of the Plains. There are several different scenarios. This is important, since the area stuck under this low will have a lot of clouds, some occasional rain showers and really cool conditions.
It looks like we will have to deal with this low on Sunday. We might see some morning sunshine, but skies will quickly cloud up. There will be showers and possibly even a thunderstorm on Sunday afternoon into the evening. Temperatures should be able to climb into the 60's early then stay there.
The question mark over the forecast gets much bigger for Monday and Tuesday. Some scenarios show the low stalling over Minnesota, which would keep us chilly, cloudy, and rainy. Some other scenarios show the low easing eastward or having a break, then having a second low move over us. So, I'm keeping a lot of clouds around with the chance of showers. Highs will only be in the 50's to near 60. But, I don't have a lot of confidence in that forecast.
Flooded Roads Still in Osseo, Southern MN
Meanwhile, the flood warnings remain in south central Minnesota. Several roads from Mankato through Waseca, then in and south of Austin, and in the Lanesboro area are still flooded (see MnDOT road reports map). Also, US 169 in the Osseo area is still flooded. One person in Wisconsin was killed when a mudslide hit his home. Note that this doesn't include any county or local roads that could be flooded. Observe all detours and do not drive into standing or moving water.
Confidence Level: "I Will Still Have Dandruff Tomorrow"
Friday 9/23: Mostly cloudy with some spotty drizzle, breezy, and continued humid. A good chance of showers and thunderstorms in the afternoon. High: between 63 and 68. Winds: NE 8-15 MPH in the morning, becoming SE 10-20 MPH. Chance of measurable rainfall: 20% in the morning, 50% in the late afternoon.
Friday Night: Cloudy, breezy, and mild with mainly evening showers and thunderstorms. Low: between 57 and 62. Winds: SE 8-15 MPH. Chance of measurable rainfall: 50% evening, 20% after midnight.
Confidence Level: "A Squirrel Will Squawk At Me" (they really hate me...)
Saturday 9/24: Partly sunny, breezy, warmer, and sticky with a good chance of afternoon showers and thunderstorms. High: between 72 and 76. Winds: SE 10-20 MPH. Chance of measurable rainfall: 20% in the morning, 60% in the afternoon.
Saturday Night: Showers and thunderstorms likely in the evening with heavy downpours possible. Storms ending late at night. Low: between 57 and 62. Winds: SE 10-20 MPH, becoming SW late. Chance of measurable rainfall: 80%.
Sunday 9/25: Maybe some morning sun, then mostly cloudy in the afternoon. A chance of a shower or thunderstorm late. Breezy and cooler. High: between 64 and 68. Winds: SW 10-20 MPH. Chance of measurable rainfall: 40%.
Confidence Level: "The Cat Will Not Sit on My Grading"
Sunday Night: Mostly cloudy with occasional rain or showers, breezy and cooler. Low: between 45 and 50. Winds: NW 10-20 MPH. Chance of measurable rainfall: 50%.
Monday 9/26: Maybe some morning sunshine, then mostly cloudy in the afternoon, breezy, and much cooler with occasional rain showers. High: between 55 and 60. Winds: SW 8-15 MPH. Chance of measurable rainfall: 30%.
Monday Night: Mostly cloudy with occasional rain or drizzle, breezy and cool. Low: between 45 and 50. Winds: NW 8-15 MPH. Chance of measurable rainfall: 30%.
Tuesday 9/27: Mostly cloudy, breezy, and cool with some spotty sprinkles. High: between 57 and 62. Winds: NW 8-15 MPH. Chance of measurable rainfall: 20%.
Extended: Sunshine returns for the middle of next week with slowly warming temperatures??
Forecast Confidence (10 - "Know what gas will
cost next week, Bob?"; 0 - "Been a victim of road rage lately, Bob?"): 7 Friday and Friday night, 6 Saturday through Sunday, 4 Sunday night and Monday, 2 Tuesday.
Yesterday's High: 63°F; Overnight Low (through 3 AM): 55°F
St. Cloud Airport Precipitation (through 3 AM Friday): 0.04 inch; SCSU Precipitation (through 3 AM Friday): TBA
Normal Temperatures for September 23 - High: 67°F;
Next Update: Monday, September 26 8:00 AM (or as needed)
Ground and Air Travel
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!
Are you interested in studying meteorology? If so,
go to the Earth and Atmospheric Sciences Department home page.