St. Cloud, MN Weather Forecast

Daily, Sometimes Twice Daily Storms, Continued Overnight

Why are we getting nearly daily thunderstorms, even though it hasn't been that hot in central Minnesota (no higher than 87 degrees so far in July on the NWS St. Cloud July temperature graph, no high of 90 degrees since May 27)? Because the parade of storms from the northeastern Pacific Ocean then near the US-Canadian border (see College of DuPage North America mid-level water vapor loop) has remained close to Minnesota. There were outbreaks of thunderstorms from the line of strong storms that went through late Monday evening, then the afternoon storms that fizzled in central Minnesota (see College of DuPage continental US clean infrared satellite loop), to the line of thunderstorms that has been pushing west-to-east just to the north of St. Cloud during the early morning hours (see College of DuPage north central US radar loop). Even though temperatures never got out of the 70's yesterday due to all the clouds, the sultry air along the front produced highs in the 90's in central South Dakota (see yesterday's 4 PM NWS WPC North America zoom-in map). Dew points near the front were in the oppressive lower 70's, producing 4 PM heat indices above 100 degrees near Pierre (see NWS South Dakota hourly weather round-up). That air, lifted more strongly overnight, since the south winds are above the ground and aren't slowed by friction, produced this new area of repeating thunderstorms from the Dakotas into central Minnesota.

Flood Watch Until 10 AM St. Cloud and North

The area just to our north has seen waves of thunderstorms since yesterday afternoon. That's why the National Weather Service has issued a flood watch until 10 AM this morning. Flooding has been observed along the west and southwest shores of Lake Mille Lacs.

AM Storms, PM Break, Except Southern Minnesota

Today, the upper-air storm moving along the Montana-Canadian border (see counterclockwise circulation center on the College of DuPage North America mid-level water vapor loop) will push to near the Minnesota-Ontario border by this afternoon. That will slowly push the stalled central Minnesota front to near the Minnesota-Iowa border by this afternoon. There will be waves of thunderstorms today, the morning one in central to southern Minnesota, as has been the case overnight. The afternoon storms will tend to concentrate near the southern edge of the leftover clouds from the morning thunderstorms, so they will tend to be a bit further south near the Iowa-Minnesota border. That's where today's and this evening's highest risk of severe thunderstorms and heaviest rain (see Day 1 of NWS WPC quantitative precipitation forecast) will be. The chance for central Minnesota thunderstorms will be smaller than they have been during the Wednesday early morning hours, but we still might see a scattered thunderstorm.

Again, we will have a lot of leftover clouds from the morning storms, so highs will be limited to the upper 70's to perhaps 80 and the dew points will remain in the middle to upper 60's, possibly brushing 70 as they have overnight (see NWS: last 72 hours of St. Cloud observations)

Rain Chances Diminish After Today 

After today, however, we are going to see a change in the pattern. The main storm track is going to be split. The storms we've been seeing will be pushed further to the south through the weekend (see Days 2-5 on the  NWS WPC quantitative precipitation forecast). Minnesota will have weak northerly flow, so warm, but slightly less humid air will move in. Dew points should drop tonight to the more comfortable upper 50's. Tomorrow, we will be warmer as we will see more sunshine, so highs will get back into the 80's. That will continue on Saturday. The humidity break will be short-lived, as the ground moisture will help dew points climb back into the 60's. While there will be no strong storm to organize thunderstorms, we could see some isolated (1 chance in 5) afternoon showers.

Looking for July Heat? You Could Get Your Wish Sunday into Early Next Week

However, the main change in the upcoming weather pattern will be the intensification of the high pressure system over the Rockies (see large clockwise circulation on the College of DuPage North America mid-level water vapor loop). Right underneath that high, high temperatures have been over 100 degrees with 110's in the Desert Southwest (see yesterday's 4 PM NWS WPC North America zoom-in map). That high is expected to push into the central and even the Northern Plains by the weekend. I've noted many times that the forecasts of this heat 5 days in advance don't have a great track record. However, this time, the northern fringe of the heat, where the forecasts are most often missed, is forecast to be north of the Canadian border, so this forecast may work out.

I'm not ready to talk about highs in the 100's in St. Cloud yet (most of the computer guidance has been far too hot this warm season), but I favor highs at least in the 90's by Sunday. 100's will definitely be possible downwind of the Buffalo Ridge and in the Dakotas. At this point, I am thinking more about dew points in the 60's rather than the 70's, so we will be borderline between the criteria for extreme heat warnings and heat advisories (see NWS Heat Risk forecast).

The hot high is forecast to remain over or close to Minnesota through the early part of next week. However, the Canadian storm track is forecast to get closer to Minnesota by Tuesday. That would bring us into the more uncertain forecast area. The persistent southwest-to-northeast flow will also have a chance of bringing high moisture air producing the daily thunderstorms over Mexico (see white and green blobs on the College of DuPage North America mid-level water vapor loop) much closer to us. So, I would guess the heat could hold through at least Monday (chance for upper 90's or 100's?), but we will have to consider more clouds and thunderstorm chances by Tuesday and Wednesday.