Friday, August 26, 2016 4:16 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
Quietly Warm Today, Then Humidity (and Storms?) Return for the Next Several Days
Wednesday's Tornado Outbreak in Ohio, Indiana
The damage surveys from the National Weather Service offices in Indianapolis and northeastern Indiana show at least 12 tornadoes touched down Wednesday from northern Indiana into Ohio. The one that did the most damage hit Kokomo with estimated wind speeds of 150 MPH.
Cool and Cloudy Yields to Milder and Sunny Today
Meanwhile, the warm and sticky air mass that triggered those storms moved further away from Minnesota yesterday (see infrared loop from College
of DuPage Satellite and Radar Menu), but we had a lot of afternoon low clouds from an upper-level low pressure system working its way across northern Minnesota (see water vapor loop from from College
of DuPage Satellite and Radar Menu). High temperatures were kept down to around 70 degrees (see NWS: Last 72 hours of St. Cloud Observations) by the cooler air.
However, those clouds broke up late in the afternoon. High pressure built into Minnesota (see NWS
WPC Latest North American zoom-in surface map), calming the winds. Still, the effect of the rains of the past two months is keeping the dew points in the middle 50's in much of central and southern Minnesota (see UCAR
Minnesota surface chart loop). There are a couple of pockets with temperatures near 50 in Little Falls and Long Prairie, but most temperatures have stayed in the middle 50's in central Minnesota.
We will continue to be in the cooler air mass today, but we'll see a lot more sunshine, so highs will climb well into the 70's.
Stormy Saturday Both Early and Late
However, we will only have one day in complete sunshine. Already, there are two storm systems, each with its own cloud patch. One is moving from Alberta into Montana and the other is coming from the central Rockies (see infrared loop from College
of DuPage Satellite and Radar Menu). By tonight, the southern one will begin to pump warmer and more humid air over the Canadian air we have now. That will trigger a chance of showers and thunderstorms during the late night and early morning hours. More showers and thunderstorms will develop late tomorrow afternoon and last into the evening from the Montana system. Since we will remain cloudy for most of the day, I expect high temperatures similar to yesterday, hanging around the 70 degree mark.
Summer Humidity Sequel Begins Sunday and Stays for Much of Next Week
Beyond tomorrow, a new storm pushing southward from Alaska (see Canadian Infrared satellite loop in Hemispheric Products from College
of DuPage Satellite and Radar Menu) will force steering winds into the southwest through the central portion of the country. This will reinforce the flow of warm and sticky air into the northern Rockies and the Northern Plains. The boundary of the sultry air with the cooler air is forecast to remain close to Minnesota from Sunday well into the next week. That will pump the humidity up to at least uncomfortable levels and give us a chance of showers and thunderstorms.
It's hard to pin down the best chances for storms, but another round could happen late Saturday night into Sunday morning as the sticky air gets closer. It may be possible for central Minnesota to break out of the clouds at times. If so, temperatures will climb into the 80's and could even make a run at 90 degrees. Right now, it looks like our best chances for getting into the heat is Monday, but that is also a shaky forecast.
The front will continue to hang around on Tuesday, raising the chances for more showers and thunderstorms and keeping the humidity levels uncomfortable. So, the main run of the State Fair may have a lot of summer-ish weather.
Tropical System to Produce Major Rain Over Florida
In the Atlantic Tropics early this morning, there are now three systems of interest (see loop of Meteosat satellite images from the University of Wisconsin SSEC), but the one with a name will have the least impact on the US. Yesterday, Gaston weakened back to tropical storm strength as top winds reduced to 65 MPH. The storm could intensify back to a hurricane in the next couple of days, but the track will keep it far from the US and, with luck, away from Bermuda. However, the cluster of storms working its way across Hispaniola and Cuba is also beginning to move moisture on its edge across Florida. The odds of this system becoming an organized storm over the weekend have dropped, but it still could end up being a huge rain producer over Florida. And another cluster of clouds that produced unwanted rain yesterday from east Texas across Louisiana and Mississippi (see infrared loop from College
of DuPage Satellite and Radar Menu) will drift westward over the next day or two, enhancing the rain potential along the northern Gulf Coast.
Confidence Level: "I Will Still Have Dandruff Tomorrow"
Friday 8/26: Sunny in the morning, partly sunny in the afternoon, less windy, and warmer with comfortable humidity. High: between 70 and 75. Winds: S 5-15 MPH. Chance of measurable rainfall: 10%.
Friday Night: Clouding up, breezy, and not as cool. Noticeably humid. A chance of late night showers and thunderstorms. Low: between 54 and 58. Winds: SE 5-15 MPH. Chance of measurable rainfall: 40%.
Saturday 8/27: Morning rain showers, then mostly cloudy with perhaps a brief break of afternoon sunshine. A better chance of late day showers and thunderstorms. High: between 70 and 75. Winds: E-SE 10-20 MPH. Chance of measurable rainfall: 40% in the morning, 60% late in the day.
Confidence Level: "A Squirrel Will Squawk At Me" (they really hate me...)
Saturday Night: Chance of rain showers early evening and late at night. Turning more humid. Low: between 60 and 65. Winds: SE 8-15 MPH. Chance of measurable rainfall: 40%.
Sunday 8/28: Maybe an early shower or thunderstorm, then partly sunny, breezy, warm, and uncomfortably humid. High: between 84 and 88. Winds: SW 10-25 MPH. Chance of measurable rainfall: 50%.
Sunday Night: Partly cloudy, breezy, and sticky with a chance of a shower or thunderstorm. Low: between 65 and 70. Winds: SW 8-15 MPH. Chance of measurable rainfall: 30%.
Monday 8/29: Perhaps an early shower or thunderstorm, then partly sunny, breezy, hot, and uncomfortably humid. High: between 88 and 92. Winds: SW 10-20 MPH. Chance of measurable rainfall: 30%.
Confidence Level: "The Cat Will Not Sit on My Grading"
Monday Night: Partly cloudy, breezy, and still humid with a chance of a shower or thunderstorm. Low: between 62 and 66. Winds: NE 5-15 MPH. Chance of measurable rainfall: 30%.
Tuesday 8/30: Partly to mostly sunny, but not quite as warm or as humid. High: between 82 and 86. Winds: E 5-15 MPH. Chance of measurable rainfall: 30%.
Extended: Warm, sticky, and potentially stormy for much of the upcoming week??
Forecast Confidence (10 - "Know what gas will
cost next week, Bob?"; 0 - "Been a victim of road rage lately, Bob?"): 7 Friday, 6 Friday night and Saturday, 5 Saturday night, 4 Sunday through Monday, 3 Monday night and Tuesday
Yesterday's High: 71°F; Overnight Low (through 4 AM): 50°F
St. Cloud Airport Precipitation (through 4 AM Friday): None; SCSU Precipitation (through 4 AM Friday): None
Normal Temperatures for August 26 - High: 78°F;
Next Update: Saturday, August 27 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.