textproduct: Twin Cities

KEY MESSAGES

- Another round of strong to severe storms arrives by late evening, lasting into Wednesday. Strong winds and hail are the primary risks, with a non-zero chance for a tornado. Heavy rain could also lead to localized flooding, with the best chance in central MN.

- Additional chances for showers and storms decreases after tomorrow, with temperatures increasing into the weekend and early next week. Heat headlines may be needed.

DISCUSSION

Issued at 315 AM CDT Tue Jul 7 2026

Regional radar mosaic shows the decaying line of showers and storms pushing through southern Minnesota as of 245am, with the only real storm to speak of in southwestern Minnesota. The rest of the line has largely crumbled into some rumbles of thunder without any notable updrafts, and this is expected to remain the case as it further weakens heading south into Iowa. Some gusty winds are also still present on the order of 30-40mph within the showers, falling back as it moves out this morning. We quickly transition away from the morning round of storms to another round expected to arrive during the evening today lasting into Wednesday, with the best chance for severe storms looking to be west-central into central Minnesota where the combination of a strong shortwave embedded within zonal upper level flow combines with a screaming 850mb LLJ around 00z to form clusters of storms where ND/SD/MN meet. A surface low spinning up will also produce a subtle thermal boundary overspreading the area, the position of which will likely dictate the southern extent of the showers and storms. PWATs are within the top 99th percentile within the NAEFS over western MN at 06z, showcasing the robust WAA/moisture advection via the LLJ. Areas of flooding are probable depending on the amount of moisture received from tonight's round of storms, and a short-range flood watch may be needed ahead of time as we see guidance come together this afternoon. As for severe storms, forecast soundings from western MN showcase 750-1500 J/KG MUCAPE, likely being undercut by the significant WAA in the lower levels from the LLJ. Time of day also plays a factor, given the best forcing arrives after 00z and lasts into the early morning hours of Wednesday. Given the nocturnal nature, strong winds will certainly be a threat, with hail also possible. There is a non-zero tornado risk as LCLs will be below 1000ft with significant low level speed shear and a veering profile making for a decently curved hodograph. Overall there will likely be some severe storms and the main question is how widespread the coverage ends up, and if competing factors such as the high PWATs cuts into hail production or the low level capping keeps storms from being surface based.

This cluster of storms is expected to continue to migrate eastwards across central Minnesota overnight with continued scattered storms forming until the cold front pushes out of the area later in the day on Wednesday. Areas that get hit by multiple rounds of storms overnight and during the day Wednesday have the greatest chance for localized flooding, with HREF PMM values exceeding 3 inches in portions of central Minnesota hovering near the border of the FGF/DLH/MPX CWAs. Ensemble max values of near 5-6'' highlights just how anomalous the moisture content and potential for flooding is within this system. Showers will end from northwest to southeast as the final frontal boundary moves through, leaving us drying out overnight Wednesday into Thursday.

As the last of the showers and storms depart, the forecast focus shifts towards the significant heat dome building over the central CONUS by the end of the weekend and into next week. NAEFs forecast values for 500mb heights are maxed out or never before seen, with some model guidance pushing out 600dam heights by Monday morning. Even the AIFS guidance which would tend away from the most anomalous forecast shows over 594dam heights, with the position for the center of the ridge favoring the central plains. Model guidance is already picking up on the significant heat likely arriving with this heat dome, with the deterministic ECMWF showcasing highs in the triple digits at MSP early next week and overnight lows for a few days around 80. While this is towards the upper end of guidance, it shows just how significant the coming heat will be. Within the ensemble guidance, the lowest forecast temperatures in the Twin Cities on Tuesday are in the low to mid 90s, so significant heat is all but certain even at this time scale. We will have far more to share as we get a bit closer, but expect to see a lot of chatter about the incoming heat in the days to come.

AVIATION /06Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 1247 AM CDT Tue Jul 7 2026

As expected, the line of storms that moved into central MN back closer to sunset is now rapidly falling apart and only some sprinkles and cloud cover are expected to make it as far as EAU and MKT. See no reason for the decreasing trend not to continue with nocturnal stabilization of the atmosphere and the lack of a LLJ to sustain convection tonight. Other concern we're watching is the potential for stratus/fog over central MN as clouds clear out. From the HREF perspective, it's AXN up toward the Arrowhead that will be most susceptible to seeing fog/stratus develop, so that was the one place we got a bit more aggressive with the stratus potential. For Tuesday, we'll have a weak boundary stalled out over central MN into northwest WI. You can't rule out a shower/storm developing along the boundary during the afternoon, but it's the 00z to 04z window where we should start seeing west central MN light up with convection, which means during this period, it's AXN that has the best chance of TS with this next round, since most of the other terminals will get in on the action after 6z Wed.

KMSP...Lightning activity has dropped off considerably with the line of showers moving through, so left the TS mention out for this first batch of precipitation. VFR conditions and light winds are expected for the rest of tonight and all of Tuesday. The last 6 hours of this TAF period will see the return of TS potential. It will be an active 6 hours, but still questionable if MSP will be in the multiple rounds of storms, or if we'll be in the bleachers watching storms rake the north metro.

/OUTLOOK FOR KMSP/ WED...MVFR/SHRA likely, chc IFR/-TSRA. Wind SW to NW 5-10kts. THU...MVFR chc IFR cigs in mrng. VFR aftn. Wind NE 5-10kts. FRI...VFR. Wind SE 5kts.

MPX WATCHES/WARNINGS/ADVISORIES

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