St. Cloud, MN Weather Forecast

Warnings and Watches for Weekend Heat Wave

Today is when the extreme heat returns (see red areas Sat-Mon on the NWS Heat Risk forecast). Nearly all of Minnesota is under a heat advisory (orange on the NWS continental US watch-warning map), which extends to Oklahoma, north Texas, and Arkansas. A swath of central and southern Minnesota, including the entire Minnesota River Valley, the Twin Cities Metro and the area between the Twin Cities and St. Cloud, Albert Lea, and Jackson is under an extreme heat warning from noon today and noon tomorrow. There is an extreme heat watch for Sunday afternoon and evening for both the heat warning and the heat advisory areas. In the Twin Cities, the extreme heat warning extends until 6 AM Monday, for now.

So, keep an eye on kids, seniors, people who are pregnant or have breathing or heart issues, and other people vulnerable to the heat. That risk could continue into early next week. You can check the latest Minnesota heat index (88+), dew points, and temperatures on the NWS Minnesota hourly weather round-up.

90's or 100's Likely Depends on Humidity (More Humid Means Lower Temperatures)

Highs will be in the 90's, but the main question is how humid it will be. There is a swath of dew points in the uncomfortable upper 60's to oppressive lower 70's in the eastern Dakotas and much of Minnesota (see UCAR hourly dew point chart). There will be a tendency for dew points to back off a bit during the afternoon as we get hotter. If the dew points manage to fall to the lower 60's or upper 50's, temperatures could climb into the 100's as it did in the western Dakotas yesterday (see yesterday's 4 PM CDT North America zoom-in map). If the air doesn't mix as well, that would tend to keep the temperatures in the low to middle 90's, but that will also produce the extreme heat indices well up in the 100's. I think it's more likely that we have lower dew points on Monday and Tuesday than we will have today and tomorrow. The uncertainty is likely why there is only an extreme heat watch in central Minnesota and the Minnesota River Valley tomorrow afternoon and evening. Also, some of the areas in the heat advisory could get kicked up to a warning if the dew points remain higher.

Missed Most Storms Yesterday and Overnight

Once again, central Minnesota missed the bulk of the showers and thunderstorms yesterday and overnight (see yellow areas on the College of DuPage North America clean infrared satellite loop and College of DuPage north central US radar loop). A few of the storms produced large hail, damaging winds, and even a tornado in northwestern and north central Minnesota.

..And Storms Will Likely Stay North Today (Small Chance of Pre-Dawn Shower) 

There may be a chance for a few scattered showers and thunderstorms today or this evening in northern Minnesota as the hottest of the hot air pushes northward. Perhaps a storm or two will have large hail potential, but much of the area with the high heat will be too warm aloft to generate thunderstorms.

Fire Danger Becoming More Extreme Tomorrow

Hotter temperatures, breezy conditions, and the more modest dew points will also produce elevated fire danger with extreme fire danger likely tomorrow.

Next Rain Chance: Sunday Night?? Monday (early)??

That warm front will likely push southward again by some time Monday. The NWS Storm Prediction Center day 2 convective outlook shows a category 2 (of 5) risk of severe thunderstorms. There is a chance for those storms in northern Minnesota from afternoon on, but any threat in southern and central Minnesota would come with overnight storms. And, the front timing is uncertain, so the severe storm forecast is iffier than usual. At this point, there aren't any areas with heavy precipitation potential (see Days 2-3 of the NWS WPC quantitative precipitation forecast), but that's because both the location and the amount of storms are uncertain. 

Drier Heat May Linger into Mid-Week; Uncertain Rain Chances

Beyond Monday, there is a chance of another storm system pushing out of central Canada and into the Northeast. That could push another cold front through Minnesota, but the forecasts widely vary about when any such front should come through. There is the potential for continued hot highs with lower humidity through the middle of next week if we stay on the warm side of that front. That's why I have highs still in the 90's, but with lower humidity from Monday afternoon at least through Tuesday. Any rain threat would be tied up with the timing of the next front passage.

Mid-Week Heat Could Also Bring Wildfire Smoke

The smoke plume aloft (see shaded areas on the EPA fire and smoke map) The change to south winds will likely keep pollution levels to the moderate levels today and tomorrow (see Minnesota Pollution Control Agency Minnesota air quality forecast). Whenever the front comes through on Monday, our winds will become more west-northwest, so the orange levels of air quality index in the southern Canadian Prairie Provinces could push into Minnesota during the early part of next week.