St. Johns University, MN Hourly Weather Updates

Key Messages

• Scattered showers expected this evening into tomorrow morning. Most areas will not see much rain.
• Chance for storms tomorrow evening along a weak cold front.
• Temperatures this weekend and into next will hover right around the seasonal average for the middle of August.

Discussion

... Issued at 130 PM CDT Fri Aug 14 2026

Any sort of interesting weather remains south this afternoon, tied to the surface boundary across Iowa, Illinois, and Indiana. We will start to see this pattern finally break down as a midlevel wave develops and spreads east from the Canadian Rockies tonight. Spotty showers are expected tonight and Saturday as low level moisture increases in response to the developing low pressure tied to the midlevel wave. Very little lightning is expected tonight given the lack of instability, though increasing dewpoints tomorrow ahead of the cold front should be enough to build in a thousand or so joules of MUCAPE. Whether or not we`ll see any storms actually develop is uncertain, with only a few CAMs developing storms at all along the front, and even less having them develop across Minnesota. The bullish solution would be something like the 14.12Z run of the RRFS. During this whole window (Friday afternoon - Saturday evening), we`ve kept PoPs capped at around 30 to 40% at any given time. In reality, the chance of precipitation is pretty high throughout the entire timeframe, but the confidence in the exact timing for any exact point is very low.

Heading into Sunday, the front will have moved through and winds will increase out of the northwest. Slightly cooler, and much drier air will advect in. This will also help clear out any lingering wildfire smoke and cloud cover, making for the best day of the weekend.

For next week, Monday starts out similar to Sunday, with highs in the low 80s and dewpoints in the 50s and 60s. We will start to see a low level response to a deepening low pressure across Canada, increasing our winds out of the southwest. By Tuesday, dewpoints will increase well into the 60s and low 70s again, setting the stage for our next chance for notable precip as a strong cold front looks to sweep down from Canada. The latest NBM and WPC QPF amounts peak around 1-2" across southern MN. This is probably the area that needs it the least given the current drought outlook, but it is good to see rain shifting north from the areas that have been slammed the past few days. Should our moisture flow get cutoff by any storms to our south, we may see this number trend down. But as of now, this is our best chance for heavy rain. CSU`s MLP severe probability forecasts do also highlight low end chances for organized convection both Monday and Tuesday.

Surface high pressure should move in across the area again behind the fropa, resulting in a couple of quieter days to end the work week.

Aviation

/00Z TAFS THROUGH 06Z SUNDAY/... Issued at 700 PM CDT Fri Aug 14 2026

A band of light showers stretches from STC to MSP but is falling apart as it lifts north. Richer low level moisture to the south of the band is lowering cigs to IFR and MVFR, with further deterioration expected through the night. Extensive stratus will slowly lift late morning and a few breaks are possible in the afternoon.

KMSP...Light showers or sprinkles will exit or dissipate early in the period with MVFR cigs arriving soon thereafter. IFR cigs still appear likely toward dawn, persisting into mid to late morning before improvement occurs in the afternoon.

/OUTLOOK FOR KMSP/ SUN...VFR. Wind NW 10kts. MON...VFR, chc -TSRA late. Wind SW 5-10kts. TUE...MVFR/-SHRA likely, chc IFR/-TSRA. Wind SW 5-10kts.

Watches / Warnings / Advisories

/WARNINGS/ADVISORIES... MN...None. WI...None.