textproduct: Twin Cities

KEY MESSAGES

- Additional rounds of thunderstorms possible this evening and over next few days. Damaging wind gusts and locally heavy rain will be the primary hazards with these storms.

- Warm and muggy weather continues into next week.

DISCUSSION

Issued at 205 PM CDT Thu Jul 2 2026

Ah, the challenges of forecasting Summer convection! The early afternoon satellite picture is fairly busy, with plenty of cloud debris over southern MN & western WI following this morning's storms. Factor in the cloud cover with the presence of a few remnant boundaries and the forecast takes a rather complex turn, with lower than usual confidence on additional precipitation windows and anticipated intensities of severe weather. The large scale view displays troughing over the western CONUS and ridging over the Ohio Valley. The Upper Midwest is positioned within a region of zonal WSW flow between these features. Guidance displays several "ripples" within the flow that are capable of initiating thunderstorms, but these can be a challenge to resolve in weakly forced environments which is likely why we've continued to observe run to run changes across the CAM suite. The best path forward is to pair the anticipated environment with the real time surface trends, which has resulted in a downgrade of severe weather probabilities from SPC this afternoon and evening. The latest Day 1 outlook trimmed the Enhanced Risk (Level 3/5) all the way back to the far western portions of the forecast area along the Buffalo Ridge. A more expansive Slight Risk (Level 2/5) remains in place from the MN River to roughly the I-94 corridor in MN/WI and a Marginal Risk (Level 1/5) covers east central MN and the rest of western WI.

Early afternoon radar displays the eastward departure of the morning storms into southeastern MN. Stronger storms are ongoing across northern IA and will move east, away from our forecast area. Back to the west, IR satellite successful attempts at convective initiation across the Dakotas, which are tied to a subtle shortwave within the aforementioned WSW flow aloft. It's the evolution of these storms that will be the focus this afternoon and into the night. CAMs offer a myriad of solutions, from a well-defined MCS or two and the potential for slow- moving/training thunderstorms. It seems that the most likely scenario is for a complex of storms to develop and move to the ESE across southeastern SD into southwestern MN/northwestern IA this evening along an existing instability gradient. These storms would be capable of producing damaging wind gusts in excess of 70 mph and are tied to the Enhanced Risk that was shifted largely to the southwest of our forecast area. A new Severe T-Storm Watch was recently issued across eastern SD to capture these trends. CAMs highlight additional storms developing and advancing from western MN into central MN this evening, which may pose a damaging wind & large hail threat owing to 2000-2500 J/kg of MUCAPE and effective deep-layer shear ~30kts. The other piece of the ongoing puzzle is the hydro scenario, given potential for back-building/training of storms and the presence of the soupy atmospheric moisture characterized by a nearly 2 sigma PWAT anomaly. The area of greatest concern for a flash flood threat will be across southern MN/I-90 where multiple rounds of thunderstorms occurred this morning. Following latest trends in convective guidance that place the heaviest rainfall axis south of the MN/IA border tonight, we have opted to refrain from issuing a Flood Watch across southern MN. We will punt to the evening shift for an additional look at boundary placement and trends to the west and may expand the watch that runs up the MN/IA if necessary.

Lingering convection from tonight likely continues into Friday morning, which once again introduces uncertainty into the timing of PoP windows. We'll take a blend of convective guidance and run with a forecast that features 20-30% PoPs in the morning, followed by a lull in the afternoon. Temperatures are forecast to climb into the mid 80s and will pair with low 70s dew points for another day of warmth and increased humidity. A stronger shortwave is forecast to traverse the WSW flow across the Dakotas tomorrow evening and may force yet another complex/es that will move across the region tomorrow night into Saturday morning. Any storms that move through will pose a damaging wind and large hail threat.

The 4th of July will likely feature ongoing convection somewhere across the Upper Midwest/near the forecast area to open the day tied to Friday night's storms. As with the previous rounds of storms, we'll continue to monitor for slow storm motions that may support a localized flood threat. Do anticipate some dry time following the morning storms and coverage of additional storms later in the day should be limited, say scattered at best, given a lack of a large scale forcing mechanism. The warm, humid, moist atmosphere will fuel the potential for air mass thunderstorms capable of producing heavy rain and frequent lightning, however the severe weather threat is currently low Saturday afternoon and evening.

A break in the active pattern looks to setup Sunday-Tuesday, as ~588dm ridging expands north of the Upper Midwest and associated surface high pressure builds over the Great Lakes. Temperatures should run near normal in the mid 80s through at least the first half of next week. The breakdown of the ridging is accompanied by the return of precipitation chances across the ensemble membership for the second half of next week.

AVIATION /00Z TAFS THROUGH 06Z SATURDAY/

Issued at 653 PM CDT Thu Jul 2 2026

A highly uncertain TAF given several chances for scattered storms, some strong to severe, and uncertainty on specific placement, timing, and general evolution. Winds will be generally light and variable overnight before turning more southeasterly on Friday. Skies will generally be scattered to broken at the mid-level, with few around the 030-050 level likely with convection/showers. Visibility impacts are most likely in the evening/overnight time frame and again around daybreak timeframe Friday morning due to possible patchy fog, similar to this morning, as well as with any passing storms/heavy rain.

Higher confidence of TSRA for our western/southern sites this evening before this line of storms decays. Additional line of storms is possible around daybreak moving from southern Minnesota northeast toward the Twin Cities and western Wisconsin. I have added PROB30s to our W WI sites for this round, but confidence is lower for MSP.

KMSP... Confidence in thunder is low as the storms are weakening as they move towards MSP. I kept the TAF dry, but it's looking increasingly likely that we'll see scattered showers arrive at the terminal by 05Z. This will be AMD by 03Z if the line of storms and showers can hold together. Minimal winds through the period, AOB 10 knots and VRB or southerly in direction. Scattered to broken skies through the day, with brief dips to low end VFR if showers move through tonight. Guidance continues to show another round of showers and storms around daybreak 11-14Z, but agreement between models on when and where is low. I have opted to leave that out of the TAF given the high uncertainty with this first line of storms/showers.

/OUTLOOK FOR KMSP/ SAT...Chc MVFR/TSRA. Winds NE 5-10 knots. SUN...VFR. Winds NE 5-10 knots MON...VFR. Winds SE 5-10 knots

MPX WATCHES/WARNINGS/ADVISORIES

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