St. Cloud, MN Weather Forecast

Back to the Heat and Oppressive Humidity Yesterday...

St. Cloud reached 91 degrees again yesterday (see NWS: last 24 hours of St. Cloud observations) with dew points hanging in the Florida-like low to middle 70's (see lower left digit when you set the NWS Aviation Weather Center METAR map to 19Z-22Z, 2-5 PM), so the heat index was as high as 96 degrees in St. Cloud and near or above 100 in west central and south central Minnesota, where the temperatures got to about 90, but the dew points were in the upper half of the 70's (set time to 3-5 PM on the NWS Minnesota hourly weather round-up).

The heat and humidity produced showers and thunderstorms in South Dakota (set number of frames to 200 on the College of DuPage north central US radar loop), many of which produced wind damage. Some of those storms moved into central and southwestern Minnesota overnight (see College of DuPage north central US radar loop). Again, there wasn't much rainfall produced, so they didn't really help the water shortfall (see extremely low flow in the Mississippi River, orange and red readings, on the USGS National Water Dashboard when you zoom into Minnesota) 

...And Likely Today

That will leave the intense humidity (see latest NWS Aviation Weather Center METAR map) from eastern South Dakota into Minnesota and Iowa (dew points in the oppressive 70's with hurricane-like upper 70's red on the UCAR hourly dew point map). 

So, there will again be some leftover early clouds (see College of DuPage North America clean infrared satellite loop), but we will again break out into hazy sunshine (still dust aloft from the Canadian wildfires; see EPA fire and smoke map). Highs will again climb into the 90's with uncomfortable dew points (see NWS Minnesota hourly weather round-up for the latest temperatures, dew points, and heat indices when 88 or higher). The National Weather Service has issued an extreme heat warning (dark red) for all of central and southern Minnesota and even a few parts of northwestern (Red River Valley) and northeastern Minnesota. In the St. Cloud area, there is a heat advisory until late this morning, then the extreme heat warning is in effect between 11 AM and 9 PM. In the Twin Cities Metropolitan area, a heat advisory goes into effect for the rest of the night after 9 PM.

So, keep an eye on kids, seniors, people who are pregnant or have breathing or heart issues, and other people vulnerable to the heat. 

Chance of N MN Storms Tonight, Perhaps Reaching Central Minnesota

The warm front across central Minnesota (see yesterday's 4 PM CDT North America zoom-in map) will likely push southward tonight into tomorrow morning. That will set off more showers and thunderstorms in northern Minnesota this afternoon into this evening with all types of severe weather possible (forecasters at the NWS Storm Prediction Center may upgrade the severe weather threat to category 3 of 5 from northern Minnesota into Wisconsin). That's also where the best chance for significant rain will be (see Day 1 of the NWS WPC quantitative precipitation forecast). The central and southern Minnesota storm threat will be mainly tonight with a category 2 risk of severe weather. 

Perhaps Hotter, But Not as Humid Tomorrow PM

Any storms and leftover clouds should wind down early tomorrow morning. Then, our winds will become more southwesterly, bringing air from the western portion of Kansas and Nebraska. That air is still hot (see again the 100-plus highs on yesterday's 4 PM CDT North America zoom-in map), but didn't have the oppressive humidity during the afternoon heat. So, we could see an upper 90's high Monday with a heat index close to the actual temperature. That would likely produce another heat advisory (see red area for Monday on the NWS Heat Risk).

Still Very Warm Through Mid-Week, Lower Humidity?

As we head to the middle of next week, the hot high pressure will recede a bit westward to the central Rockies. Minnesota will either be in the eastern edge of the hottest temperatures or just on the cool side of the front marking the eastern limit of the heat. Some of the guidance has highs well up in the 90's, but others are cooler. So, I have a high back near 90 on Tuesday, with highs into the 90's on Wednesday. I am leaning to no worse that dew points in the lower 60's with upper 50's possible. Any air from the southern Canadian Prairie Provinces could also produce increased low-level smoke (see EPA fire and smoke map).

Uncertain Mid-Week Storm Chances (Thursday Better Chance??)

There will be an uncertain chance of scattered showers and thunderstorms through midweek, since storms will be reinforcing the northwest to southeast flow from the Great Lakes into the northeast. So, I have a small chance for showers and thunderstorms, but that threat is really uncertain.

At this point, more of the computer forecasts agree about the potential of a stronger storm triggering showers and thunderstorms on Thursday (see Days 4-5 of the NWS WPC quantitative precipitation forecast). I am skeptical of that forecast being accurate, but I have a slightly greater chance for storms and a cooler high temperature for Thursday. That uncertainty of the forecast continues into next weekend.