textproduct: Twin Cities

KEY MESSAGES

- Today will be the last day of critical fire weather conditions, possibly of the Spring. We will have very low RHs again on Saturday, but without the wind, with a considerably more moist airmass expected Sunday through next week.

- Scattered thunderstorms are expected across southern Minnesota and western Wisconsin this evening. The strongest storms could contain large hail.

- Multiple rounds of storms expected Sunday through Monday. Severe storms look likely Sunday evening and again Monday afternoon and evening.

- Quieter weather expected the rest of next week, with below normal temperatures Tuesday and Wednesday.

DISCUSSION

Issued at 257 PM CDT Fri May 15 2026

We'll start with today. There's a sub-990mb surface low currently in northwest Ontario. The pressure gradient associated with it extends south into northern MN, but down here in central/southern MN, we're in a bubble high between that Ontario low and lee-side low near the OK Panhandle. This bubble high is giving us a weak pressure gradient and considerably lower winds than what they're seeing in northern MN today. The other impact of this pressure pattern is the cold front moving across MN is starting to put on the brakes, which sets the stage for our first convective potential of the next several days. It's not exactly cold behind the front, but dewpoints have crashed into the 30s behind the front, with 40s and some low 50 dewpoints ahead of it. As we move out into the 6pm to 9pm timeframe, the HREF shows this cold front stalling out, with moisture even surging a bit back northwest in this time range. We will see dewpoints creep back up into the mid/upper 50s south and southeast of Mankato. Aloft, the MN/IA border region will find itself within the right entrance region of an upper jet across northern MN into Lake Superior. The combination of the surface front and upper divergence in the jet entrance region will provide the forcing for convection this evening. Current expectations is we'll see storms develop down around Faribault county between 5pm and 7pm, with storms developing northeast along the front from there. We'll have enough shear and instability to support rotating updrafts, with a hail and wind risk existing with any storms that develop. Where the SPC bumped their Slight risk in the Day 1 outlook up toward Albert Lea and Rochester looks good for where the highest severe risk will be locally. Though t The bigger severe risk for today will be down in central IA where instability will be significantly higher.

The best day of the weekend will definitely be Saturday. The front from today will sag south down into Nebraska and Iowa. We'll again see deep mixing and a crashing of dewpoints, with afternoon humidities down in the teens again looking likely for Saturday, but this time around, we'll be missing the winds for the fire weather threat. By Saturday evening, storms will have developed along the boundary to our south as it begins heading north as a warm front. Most guidance shows this convection creating and MCV in Nebraska that will track northeast across MN Sunday morning. The net result is we should see a large area of showers and storms lifting northeast through the night, with a wet Sunday morning expected as the MCV pushes across the area. As this happens, the main upper trough to the west will help strengthen a surface trough/front across Nebraska into southeast SD. At the northern edge of this surface trough, muCAPE values are expected to build to at least 2000-3000 j/kg, which will provide the fuel for aggressive convective initiation late Sunday afternoon in southeast SD. This convection should grow upscale pretty quick, with a forward propagating MCS expected to race across southern MN Sunday evening/overnight. RRFS reflectivity forecasts show bowing line segments developing Sunday evening, so we'll have to watch how things evolve, but we are certainly seeing potential for a damaging wind/QLCS tornado threat with this MCS potential Sunday evening.

For Monday, how Sunday nights activity evolves will be key to what our severe risk looks like for Monday. But on Monday, the synoptic setup looks similar to Sunday, it's just the surface front will be father east. So where Sunday sees storms develop in southeast SD, Monday afternoon, storms will develop east of the front once again, though this time likely in the vicinity of south central to east central MN. Given that we look to be where storms initiate, all modes of severe weather will be on the table, it's just a question of exactly where the surface boundary is by the afternoon. Of course there is some good with having these multiple rounds of thunderstorms and that is we will finally see some much need rainfall. Between Sunday and Monday, much of our area should see 1 to 2 inches of rain, with pockets of 2-3 inches possible. This rain will help put a stop to the flash drought we've seen here in the last 3 weeks or so. In addition, this rain combined with the greenup being complete should finally bring an end to the Spring fire season here in the MPX area.

Behind this system, we'll get northwest flow and cooler air. Highs Tuesday and Wednesday will likely struggle to hit 60, with lows Wednesday and Thursday morning falling into the 30s and 40s (with some frost being possible in central MN Wednesday morning). By Thursday, our surface winds will turn back out of the south, which will allow for highs to get back up to near normal by the end of the week. There's also some potential for a few showers to develop Thursday and Friday within this broad warm advective pattern, though the threat of any heavy rain or severe weather looks pretty low at this point.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1215 PM CDT Fri May 15 2026

Westerly winds will become breezy this afternoon as mixing increases. Peak gusts are forecast to top out between 20-25kts. VFR conditions will persist this afternoon, with the chance for a few Cu to develop between 8-10k feet. A few thunderstorms are possible across far southern MN/western WI this evening, so have maintained the PROB30 at EAU for -TSRA between 00-04z. Hi-res model guidance shows storms developing near or just to the southeast of MKT, so we may need to add in a PROB30/TEMPO later despite low confidence at issuance time. Quiet aviation weather overnight continues into Saturday, with light northwesterly flow.

KMSP...No additional concerns. Storms this evening are forecast to develop and track well to the southeast of the terminal.

/OUTLOOK FOR KMSP/ SUN...-SHRA/-TSRA likely, IFR/MVFR. Wind ESE 10-15G30kts. MON...-SHRA/-TSRA likely, IFR/MVFR. Wind SW to E 10-15G20kts. TUE...VFR. Wind WNW 10-15G30kts.

MPX WATCHES/WARNINGS/ADVISORIES

MN...Red Flag Warning until 9 PM CDT this evening for Benton- Chippewa-Chisago-Douglas-Isanti-Kanabec-Kandiyohi-Lac Qui Parle-McLeod-Meeker-Mille Lacs-Morrison-Pope-Redwood- Renville-Sherburne-Stearns-Stevens-Swift-Todd-Wright- Yellow Medicine. WI...Red Flag Warning until 9 PM CDT this evening for Barron-Polk- Rusk.