textproduct: Twin Cities

KEY MESSAGES

- Widespread rain arrives Monday, but forecast rain amounts continue to trend lower.

- A cooler pattern has arrived with highs in the 60s to low 70s through next week.

DISCUSSION

Issued at 225 PM CDT Sat Sep 12 2026

To simply put it, it finally feels like fall this afternoon. Winds still remain on the breezy side, especially across western Minnesota where gusts between 20-25 mph are being reported. These winds are remnant from a post-mid-level wave which is now located over southern Ontario. Winds will decrease this evening once this wave distances itself away from the northern plains. Skies for the rest of this afternoon should remain clear although some clouds will build from the west this evening. Afternoon highs expected to reach the mid-60s to lower 70s and lows overnight falling to lower 50s and some upper 40s north and east of I-94.

On Sunday, an upper-level trough will move east across Alberta into Ontario. The apex of this trough is forecast to sink as far south as southern Minnesota. Forcing is expected to be rather weak however its possible that a few scattered rain showers develop mainly south of the MN River Valley. However, brought slight chance PoP values up into portions of southern MN for any rouge precip that wants develop. By Sunday afternoon, a 1020mb sfc high builds in over the western Great Lakes region allowing for skies to clear with afternoon with highs near 70 degrees.

Our eyes remain fixed on Monday's forecast. There is still favorable disagreement between model membership for total QPF. For example, the EPS still holds as the wetter solution. If this system develops in favor of EPS trends, an inch of rain could fall as far north as the Twin Cities metro and closer to 1.5 inches across southern and southeastern Minnesota. On the other side of the coin, the GEFS remains incredibly pessimistic. Much of the northern half of Minnesota including the Twin Cities metro could see closer to 0.25" while southeastern MN would see near 0.75". For now, decided to remain with NBM QPF amounts which would provide 1-1.5 inches from a line south of Ladysmith, WI down to Fairmont, MN. Areas northwest of this line would see between 0.5-1.0" of rainfall.

To make sense of the model disagreement, a break down of both the EPS and GEFS can help paint the picture. Aloft, both models have a negatively tilted trough that digs in over southern Saskatchewan allowing for favorable forcing to be in place over the northern plains. However, the EPS features a tighter pressure gradient compared to the GEFS. In the lower-to-mid levels, both models favor strong warm moisture advection which clearly supports the increased rainfall chances. At the surface, beneath the negatively tilted trough aloft, the GEFS depicts 998mb surface low while the EPS shares the same feature but stronger at 992mb. Now if we factor in the GEPS (Canadian Ensemble), this favors closer to the result of what the GEFS is suggesting. Another element to be aware of is the low-end severe weather potential mainly along the I-90 corridor. the upper-level wave producing this system could make for a narrow window of wind- shear of about 30kts. The thermodynamic profiles are not impressive but with Low LCLs and combined shear, we cannot turn our head away from a small tornado threat Monday evening. In the end, the QPF forecast remains highly uncertain. Any shift in track could greatly decrease/increase QPF amounts for a given area. Of course, those who manage to see greater thunderstorm activity will have a shot at observing locally higher amounts.

Beyond Monday, much of the remaining forecast period is under zonal flow. Forecast highs will remain the the upper 60s to lower 70s. A couple of additional rain chances will arrive late Wednesday and then again on Friday.

AVIATION /06Z TAFS THROUGH 12Z MONDAY/

Issued at 1220 AM CDT Sun Sep 13 2026

VFR with light winds and mostly quiet weather through the 6z period. There is a chance for a scattered VFR showers between 12-16z at RWF & MKT, however opted to not include mention in either TAF given low confidence on observing measurable precipitation due to dry air in the lowest 5k feet of the column. Widespread deck of VFR stratus between 8-10k feet will move across the TAF sites this morning. Skies clear with WNW between 5-10kts this afternoon.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/ MON...-SHRA/MVFR likely, chc IFR. Wind SE 10-15G30kts. TUE...VFR. Wind NW 5-15kts. WED...VFR. Chc MVFR/-SHRA PM. Wind E 5-10kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None.