Wednesday, May 25, 2016 2:42 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: Wet Wednesday With Wettest Threat in Southern MN?
80's Dominate Tuesday With More Sunshine
We did end up with our promised dry day. Despite a few late day showers in western Minnesota (see infrared loop from College
of DuPage Satellite and Radar Menu), most of Minnesota had more sun than clouds. This allowed temperatures to climb back into the 80's (see 3-day loop of NWS/University of Albany high temperature maps). Dew points dropped into the slightly drier 50's (see NWS: Last 72 hours of St. Cloud Observations) and have remained there overnight. However, more humid air is sitting in Iowa and Sioux Falls and points south (see hourly UCAR dew point chart), ready to move northward as soon as the winds turn around to southeast.
Stormy Wednesday But Best Chance of Heavy Rain, Severe Weather Elsewhere??
Today, we are still dealing with the old low in southern Saskatchewan (lost much of its low clouds overnight infrared loop from College
of DuPage Satellite and Radar Menu, but the full circulation is clear on the water vapor loop). However, another storm system from the Rockies has gotten caught up in the circulation as it moved across Wyoming and into western South Dakota overnight (see water vapor loop from the College
of DuPage Satellite and Radar Menu). This storm has triggered the overnight thunderstorms that have been moving across South Dakota and Nebraska (see NWS
Upper Mississippi Valley radar loop). This system will track into the Dakotas today, setting up the Upper Midwest for enhanced chances of showers and thunderstorms.
The situation is quite complicated, because the morning storms will likely weaken, but leave a cloud line across northern Iowa. That will be the boundary where the really hot and sticky air further to the south meets the cooler air under the leftover clouds. This area near the Minnesota-Iowa border and into Wisconsin has the biggest threat of heavy rainfall and severe weather as storms redevelop this afternoon. The next biggest threat area would be western North Dakota where some of the moisture from the system in South Dakota gets pulled back into the circulation around the Saskatchewan low. This could be the area with the most persistent rain today.
In central and northern Minnesota, we will likely be cloudy most of the day and it is possible that the other area hot spots could shunt most of the showers and thunderstorms around us. I am going for a good chance of showers and thunderstoms this afternoon, but we may not get a lot of rain from those storms. That won't be clear until the storms begin to develop this afternoon. So, we might end up a lot like Monday with periods of showers mixed with a few sunny periods, but nothing heavy. I do expect enough clouds to keep highs a few degrees cooler today.
This wave of storms will move to our north and east tonight, so Thursday looks a lot like Tuesday. We may have some morning fog, but should see lots of morning sun and a mix of clouds and sun during the afternoon. Highs should climb back into the 80's.
More Storms Friday? Friday Night? Saturday?
The next system from the Rockies will push into the Northern Plains later this week. However, there is now a spread in the computer forecasts on timing. Some forecasts are trying to bring in storms as early as near sunrise on Friday with others holding the bulk of the storms off to Friday night and Saturday. I have a chance of storms on Friday, but have dropped the percentage on the Friday chances and raised them for Saturday. If we remain rain-free Friday, we could again see highs climb back into the 80's with slightly lower humidity. But, this is a shaky forecast.
Pattern of Frequent Thunderstorm Threat Continues Into Next Week
If Friday and Saturday are uncertain, then the rest of the weekend is a mess. Right now, I'm favoring a drier Sunday and a wetter Monday, but that could change. It's also possible that, even on the wetter day, the storms may focus on a different part of Minnesota than right here. However, this generally wet and warm pattern will continue until the middle of next week. We are still well behind on rainfall in central Minnesota (2.2 inches short in St. Cloud since March 1).
It's not just the threat of rainfall in Minnesota that gets iffy. There is potential for severe weather each day somewhere in the Plains states, but it's hard to pin down the threat area even a day or two in advance. There appears to be a better chance of a more widespread severe weather in the central Plains tomorrow.
Confidence Level: "I Will Still Have Dandruff Tomorrow"
Wednesday 5/25: Cloudy with showers and thunderstorms developing by late morning and continuing through the afternoon. Large hail, damaging winds, and heavy downpours are possible. ered showers and thunderstorms redeveloping. Windy and sticky again. High: between 75 and 80. Winds: SE 15-25 MPH. Chance of measurable rainfall: 30% through 10 AM, 90% after 10 AM.
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: SE 8-15 MPH. Chance of measurable rainfall: 30%.
Confidence Level: "A Squirrel Will Squawk At Me" (they really hate me...)
Thursday 5/26: Early fog, then midday and 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: 10%.
Thursday Night: Partly clear evening, clouding up late with showers and thunderstorms likely in the early morning hours. Low: between 57 and 62. Winds: E 5-15 MPH. Chance of measurable rainfall: 20% evening, 40% after midnight.
Friday 5/27: Early showers and thunderstorms, then partly sunny, warm, and sticky. Scattered afternoon showers and thunderstorms. High: between 80 and 85. Winds: S 10-20 MPH. Chance of measurable rainfall: 30% in the morning, 50% in the afternoon.
Confidence Level: "The Cat Will Not Sit on My Grading"
Friday Night: Partly clear with a good chance of late night showers and thunderstorms. Sticky. Low: between 62 and 66. Winds: SE 5-15 MPH. Chance of measurable rainfall: 50%.
Saturday 5/28: Lots of clouds with a good chance of both early morning and late day showers and thunderstorms. Continued humid. High: between 75 and 80. Winds: SE 10-20 MPH. Chance of measurable rainfall: 70%.
Saturday Night: Maybe an evening shower, then partly clear with fog possible by morning. Low: between 57 and 62. Winds: SW 5-15 MPH. Chance of measurable rainfall: 30%.
Sunday 5/29: Sunny in the morning, partly sunny in the afternoon, breezy, very warm, and not quite as humid. A slight chance of afternoon showers and thunderstorms. High: between 83 and 87. Winds: S 8-15 MPH. Chance of measurable rainfall: 30%.
Extended: Better chance of Monday storms??? Warm and frequently stormy pattern continues into the middle of next week.
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: 80°F; Overnight Low (through 2 AM): 63°F
St. Cloud Airport Precipitation (through 2 AM Wednesday): None; SCSU Precipitation (through 2 AM Wednesday): None
Normal Temperatures for May 25 - High: 71°F;
Next Update: Thursday, May 26, 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!
Are you interested in studying meteorology? If so,
go to the Earth and Atmospheric Sciences Department home page.