St. Cloud, MN Weather Forecast

A Cool, Showery Sunday

The stalled Canadian high pressure system set up in Ontario, rather than in Manitoba as was forecast (see clockwise circulation on the College of DuPage North America water vapor loop). That kept a large part of Minnesota in the clouds (see College of DuPage clean infrared satellite loop) and in the actually rain showers yesterday (set number of frames to 200 on the College of DuPage north central US radar loop). The St. Cloud Sky Central Airport picked up a total of 0.24 inch in the occasional showers (see NWS: last 72 hours of St. Cloud observations), pushing the low May total rainfall to 1.47 inch. That's still 2.19 inches below the average, ranking as the 18th driest of the 134 Mays in St. Cloud records. 

The persistent clouds also meant that yesterday's high temperature was only 68 degrees and that was reached at midnight on Saturday night (see 14-day graph of St. Cloud temperatures from MesoWest), breaking our most persistent streak of warm temperatures so far this spring (7 straight highs of at least 80 degrees). That warmth pushed the St. Cloud average May temperature to 56.1 degrees, back to within 0.1 degree of average.

Early Week Tends Eventually Drier and Warmer (Extreme N and W Minnesota Fire Issues)

The high pressure area over Ontario is still expected to dominate the circulation over the Great Lakes for the next couple of days. This will slowly allow the drier air in Wisconsin, Michigan, and Ontario (see blues and greens on the UCAR hourly dew point chart) to replace the more humid air with dew points near 60 (browns) over Minnesota now (see NWS Aviation Weather Center METAR map). However, that process will take another day.

Today will remain humid. I am a little more optimistic about some breaks of sunshine this afternoon, as the cloud area has narrowed a bit overnight (see College of DuPage clean infrared satellite loop). So, I have temperatures climbing back to the 70's, but still a 40% chance for scattered showers.

Wildfire Danger Increases First Half of Week

By tomorrow, we will be further into the drier air to our east and north. More sunshine should allow highs to return to the 80's and dew points will be back in the 50's, perhaps even the 40's. However, this will again lead to elevated fire danger in the dry parts of northern and western Minnesota likely Monday and into Wednesday. 

Significant Rainfall Chances Sometime During Wednesday-Thursday

This high will finally weaken, allowing the slow-moving storm now over Montana and Alberta (see counterclockwise circulation on the College of DuPage North America water vapor loop) to push to near the Minnesota-Canadian border. That will increase the chances for significant rainfall from showers and thunderstorms, especially sometime between Wednesday afternoon and Thursday evening (see Days 3-5 of the NWS WPC quantitative precipitation forecast). At this point, the potential for important rain in some parts of Minnesota appears better than any severe thunderstorm threat (see NWS Storm Prediction Center Day 3 convective outlook), but it is early in the forecast process. I am a bit uncertain when the best chances for showers and thunderstorms will be (Wednesday night? Thursday midday and afternoon?). 

We will likely be humid again from Wednesday night into Thursday and the additional clouds will knock high temperatures back into the 70's to near 80.

Continued Warm and Humid Friday? Weekend? Uncertain Shower Chances

The slow procession of storms will continue into late in the week, but the computer forecasts do not agree about when the next system will be close enough to produce showers and thunderstorms. I have more shower chances Thursday night and Friday, but my confidence in the forecast is quite low.

The long-range forecast shows a stronger low moving from the Pacific Ocean into the Northwestern US by the weekend. That would allow high pressure to again build into the Plains. That pattern could allow temperatures to get very warm or even hot, IF there are no lingering weak systems that could produce scattered thunderstorms in the area. That's always a problem in summer warm temperature forecasts.