Sunday, August 28, 2016 4:26 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
Back Into the Steam Bath
Dense Fog Advisory Until 9 AM
The combination of yesterday's light rain showers (see NWS: Last 72 hours of St. Cloud Observations) and more humid air moving into Minnesota (dew points now in lower 60's on the UCAR
Minnesota surface chart loop) have gathered moisture in central and east central Minnesota. So, widespread dense fog has formed with very low visibilities (see NWS
Minnesota Hourly Weather Round-Up). There is a dense fog advisory until 9 AM from Staples, Little Falls, Lake Mille Lacs, and Mora southeastward through St. Cloud, Olivia, Hutchinson, the Twin Cities to Waseca, Rochester, Albert Lea and LaCrosse.
Increasing Humidity With Storms, Heavy Rainfall Likely At Times Through Tomorrow
The pump of warm sticky air over the leftover Canadian air has also triggered an area of showers and thunderstorms that began over Lake Traverse (see infrared loop from College
of DuPage Satellite and Radar Menu) and has blossomed in the early morning hours (see NWS
Upper Mississippi Valley radar loop). These storms will continue to blossom and move northeastward after daylight, producing locally heavy downpours, and perhaps some large hail.
Over the early part of the upcoming week, both the intense storm in Alberta and another storm off the British Columbia coast (see water vapor loop from from College
of DuPage Satellite and Radar Menu) are beginning to bring their heat to the northern Rockies and the Northern Plains. The Alberta storm will track east to northeastward, so the warm and sticky air will establish itself over Minnesota through tomorrow.
Some Severe, Heavy Rain Tonight into Early Tomorrow
After this morning's storms, we have a good chance of breaking out into sunshine. High temperatures will climb well into the 80's, and depending on how early the clouds break up, we might have a shot at 90 degrees today and tomorrow. The Alberta low will eventually pull its cold front into Minnesota tonight and through central Minnesota Monday night. That means that there could be scattered showers and thunderstorms tonight and into tomorrow morning. Another round of showers and thunderstorms will develop in the afternoon. The severe weather threat both tonight and tomorrow is limited since the low pressure track is staying north of the border. More importantly, the combination of showers could produce heavy rainfall, which could trigger another round of flooding from tonight into tomorrow.
Tomorrow afternoon, the front will be in the area, so new storms will develop in central Minnesota, then push to the south and east. Probably the best chance of severe weather will be to the south, but any rainfall could aggravate the wet grounds.
Cooler with Slightly Less Humidity Mid-Week
By Tuesday, the combination of the offshore low staying put and the Alberta low moving into Ontario will change the upper-air flow pattern so that the southwest winds aloft will stay in the northern and central Rockies into BC and Alberta. Further to the east, northwest flow will set up across the central Canadian Prairie Provinces and from the eastern Dakotas eastward. That means slightly drier Canadian air will push in behind Monday afternoon's cold front. The air mass will be a little cooler than what we will see the next two days, so high temperatures will be limited to the upper 70's into the 80's. The north winds will bring in slightly drier air, but that air will pick up moisture, especially when moving over our area, which is expected to be very wet over the next couple of days. So, humidity will remain at least noticeable the rest of next week.
Tropical System to Produce Major Rain Over Florida
While the named storms are well out in the Atlantic, and the eastern and central Pacific (except for Typhoon Lionrock off Japan), two clusters of thunderstorms are causing trouble in and near the Gulf of Mexico. The storm along the north coast of Cuba (see infrared loop from College
of DuPage Satellite and Radar Menu) has the potential to produce more heavy rainfall over south Florida. And a slow moving tropical system is showing a better circulation along the Louisiana and east Texas coast (see infrared loop from College
of DuPage Satellite and Radar Menu). This could cause especially unneeded rain over the next 2-4 days.
Confidence Level: "I Will Still Have Dandruff Tomorrow"
Sunday 8/28: Chance of early showers and thunderstorms, then partly sunny, breezy, warm, and uncomfortably humid. High: between 84 and 88. Winds: S 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: SE 8-15 MPH. Chance of measurable rainfall: 30%.
Monday 8/29: Showers and thunderstorms in the morning, then partly sunny, breezy, hot, and oppressively humid. More late day scattered showers or thunderstorms possible. High: between 84 and 88. Winds: SW 10-20 MPH. Chance of measurable rainfall: 30%.
Confidence Level: "A Squirrel Will Squawk At Me" (they really hate me...)
Monday Night: Chance of evening showers and thunderstorms, then turning a little less humid late. Low: between 62 and 66. Winds: NE 8-15 MPH. Chance of measurable rainfall: 40%.
Tuesday 8/30: A sunny start, then partly sunny, breezy, but not quite as warm. Still uncomfortably humid. High: between 80 and 85. Winds: E 5-15 MPH. Chance of measurable rainfall: 30%.
Tuesday Night: Partly to mostly clear with areas of fog by morning. Low: between 54 and 58. Winds: NE 5-10 MPH. Chance of measurable rainfall: 10%.
Wednesday 8/31: Sunny, seasonably warm, and slightly less humid. High: between 77 and 82. Winds: NE 5-15 MPH. Chance of measurable rainfall: 10%.
Confidence Level: "The Cat Will Not Sit on My Grading"
Wednesday Night: Clear and cool again. Maybe some fog. Low: between 50 and 55. Winds: light E evening, SE 5-10 MPH late. Chance of measurable rainfall: 10%.
Thursday 9/1: Sunny, breezy, warm, and uncomfortably humid. High: between 77 and 82. Winds: SE 8-15 MPH. Chance of measurable rainfall: 10%.
Extended: Increase in heat and humidity late week into next weekend???
Forecast Confidence (10 - "Know what gas will
cost next week, Bob?"; 0 - "Been a victim of road rage lately, Bob?"): 6 Sunday through Monday, 5 Monday night and Tuesday, 4 Tuesday night and Wednesday, 3 Wednesday night and Thursday
Yesterday's High: 66°F; Overnight Low (through 3 AM): 58°F
St. Cloud Airport Precipitation (through 3 AM Sunday): 0.05 inch; SCSU Precipitation (through 3 AM Sunday): TBA
Normal Temperatures for August 28 - High: 77°F;
Next Update: Monday, August 29 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.