Tuesday, May 24, 2016 6:25 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
Synopsis: Showery Summerish Weather Continues With a Break in the Rain Today
Storms Generally Produce Gentle Monday Rain
A cold front was pulled from the Dakotas to western Minnesota (see 24-hour loop of NWS WPC surface maps) by the strong low pressure system over Saskatchewan (see infrared loop from College
of DuPage Satellite and Radar Menu). Ahead of that front, dew points in the uncomfortable 60's (see hourly UCAR dew point chart) produced waves of showers and thunderstorms. The heaviest of these storms stayed to our south and west, but central Minnesota caught some rain with showers in the early morning and during the late afternoon and evening. The rainfall total hasn't been that heavy (0.18 inch at the St. Cloud Airport from early Monday through 2 AM), but it continues to be needed, given the spring rainfall deficit (2.1 inches short in St. Cloud since March 1).
Wet Week, But Drier Today
Minnesota has the potential for substantial rainfall this week as we will remain along the edge of the really hot and humid air to our south all week. However, today has the potential for being a dry day. We have a lot of lingering clouds across Minnesota (see infrared loop from College
of DuPage Satellite and Radar Menu), but the early morning rainbands are moving eastward across Iowa and Nebraska, departing the Arrowhead, and in central North Dakota (see NWS
Upper Mississippi Valley radar loop). Most likely, those storms will stay away from central Minnesota, so we have a better chance for longer periods of sunshine today. That would allow temperatures to take advantage of the mild start in the lower 60's (see NWS
Aviation Center Minnesota map) and reach into the 80's throughout central and southern Minnesota today. As the front to our west flops through central Minnesota this morning, uncomfortable morning dew points in the 60's should drop back into the 50's as the day goes on. Still, with the front in the area, there is a chance of a widely scattered afternoon thunderstorm.
Today will likely have the lowest chance of rainfall of any day for a while.
Heavier Rain, Storm Potential Tomorrow from Pre-Dawn Through Evening
By tomorrow, the Saskatchewan low pressure system will pull another wave of the warmest and most sticky air back towards Minnesota. This should set us up for another wave of showers and thunderstorms from late tonight into tomorrow evening. Since the low pressure system at the ground is forecast to move right through the Dakotas tomorrow, we should see a better chance of showers and thunderstorms with more widespread significant rainfall than we had yesterday. There will be a wave of late night and early morning thunderstorms tomorrow, then another shot of showers and thunderstorms in the afternoon. The afternoon storms will have a better chance of producing large hail and straight line damaging winds. Still, we could see some midday and early afternoon sunny periods.
As the storm system moves northeastward, the chances for showers and thunderstorms will wind down tomorrow night. With all of the lingering moisture and lighter winds, there could be widespread areas of dense fog by Thursday morning.
More Sun Thursday?? More Rain Friday and Saturday???
Thursday should be a drier day, but there will be enough lingering moisture in the air to produce a few scattered afternoon showers and thunderstorms. More sunshine will mean highs poking back into the 80's.
The next storm system to trigger thunderstorms appears to be on track for Friday into Saturday morning. Pinning down who will have the best chance for storms becomes more difficult more than a couple of days down the road, especially since overnight and early morning thunderstorms will play a large role in where the afternoon storms will be. My best guess is for widespread storms on Saturday, but a chance of more sunshine on Sunday. That, however, is a very shaky forecast.
There is the potential for a widespread inch to 2 inches of rain this week in Minnesota. Storms could produce a lot more rain in some spots. This has been the case since last night in the Worthington area. There is a flash flood warning early this morning with 1.46 inches have been measured at the Airport.
Confidence Level: "I Will Still Have Dandruff Tomorrow"
Tuesday 5/24: Becoming sunny, not quite as windy, very warm, but turning less humid as the day goes on. A slight chance of a shower or thunderstorm. High: between 83 and 87. Winds: SW 8-15 MPH. Chance of measurable rainfall: 20%.
Tuesday Night: Partly clear, breezy, and not quite as warm. A good chance of showers and thunderstorms in the early morning hours. Low: between 57 and 62. Winds: SE 5-15 MPH. Chance of measurable rainfall: 20% evening, 50% after midnight.
Wednesday 5/25: Cloudy with showers and thunderstorms likely through the morning. Maybe a few afternoon sunny breaks, but also some scattered showers and thunderstorms redeveloping. Windy and sticky again. High: between 75 and 80. Winds: SE 15-25 MPH. Chance of measurable rainfall: 70%.
Wednesday Night: Maybe a lingering evening shower, then partly clear, warm and sticky. Some areas of dense fog possible by morning. Low: between 62 and 66. Winds: light S. Chance of measurable rainfall: 30%.
Confidence Level: "A Squirrel Will Squawk At Me" (they really hate me...)
Thursday 5/26: Early fog, then afternoon sun, breezy, and very warm, but not quite as humid. A slight chance of a late day shower or thunderstorm. High: between 82 and 86. Winds: SW 8-15 MPH. Chance of measurable rainfall: 20%.
Thursday Night: Partly clear and still mild with noticeable humidity. Maybe some fog by morning. A slight chance of a late night shower or thunderstorm. Low: between 57 and 62. Winds: SE 5-10 MPH. Chance of measurable rainfall: 20%.
Friday 5/27: Partly cloudy, warm, and sticky with a chance of showers and thunderstorms. A better chance in the afternoon. High: between 75 and 80. Winds: S 10-20 MPH. Chance of measurable rainfall: 50%.
Confidence Level: "The Cat Will Not Sit on My Grading"
Friday Night: Partly clear with a better chance of late night showers and thunderstorms. Sticky. Low: between 62 and 67. Winds: SE 5-15 MPH. Chance of measurable rainfall: 50%.
Saturday 5/28: A good chance of showers and thunderstorms. Continued humid. High: between 75 and 80. Winds: S 8-15 MPH. Chance of measurable rainfall: 50%.
Extended: More sunshine, very warm and humid on Sunday?? Better chance of Monday storms???
Forecast Confidence (10 - "Know what gas will
cost next week, Bob?"; 0 - "Been a victim of road rage lately, Bob?"): 8 Tuesday, 6 Tuesday night through Wednesday night, 5 Thursday and Thursday night, 4 Friday, 3 Friday night and Saturday, 2 Sunday, 1 Monday.
Yesterday's High: 78°F; Overnight Low (through 6 AM): 58°F
St. Cloud Airport Precipitation (through 6 AM Tuesday): 0.16 inch; SCSU Precipitation (through 6 AM Tuesday): 0.10 inch
Normal Temperatures for May 24 - High: 71°F;
Next Update: Wednesday, May 25, 2016 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!
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go to the Earth and Atmospheric Sciences Department home page.