textproduct: Twin Cities

KEY MESSAGES

- Isolated storms remain possible this afternoon through tonight, however the threat of severe weather has decreased.

- Independence Day forecast features scattered thunderstorms in the afternoon and evening. The severe weather threat is low.

- Warm and humid weather persists into next week. A lull in storm chances arrives Sunday-Tuesday, followed by a return to an active pattern for the second half of next week.

DISCUSSION

Issued at 225 PM CDT Fri Jul 3 2026

Another day and yet another complex scenario across the Upper Midwest owing to weak forcing aloft and the presence of a moisture rich atmosphere. A cluster of showers with isolated storms developed ahead of a moisture axis in western MN. Updrafts have struggled to sustain in the weakly sheared environment, however we have boosted PoPs across the western forecast area to account for near term shower/isolated storm chances.

As referenced in previous discussions, the placement of remnant surface boundaries and nebulous ripples in the WSW flow aloft continue to be the main pieces of the puzzle to defining PoP windows over the next 36-hours. Early this afternoon, regional IR satellite captures deep convection ongoing across northern Illinois along with a second complex across southwestern Iowa/northwestern Missouri. Both complexes will remain well to the southeast of the forecast area, but have laid down outflow boundaries that will play a role in the evolution and track of upstream storms/MCS activity is forecast to develop in the South Dakota/Nebraska vicinity later this afternoon. A better defined shortwave traversing the WSW flow aloft over the Dakotas will be the driver of additional convection, with two "general regimes" that will bear watching this evening. The first headline making regime will be surface based convection that develops and tracks southeast along a strong instability/theta-e gradient in eastern Nebraska/central Iowa (Paired with SPC's Day 1 Enhanced Risk). The second regime is associated with upper-level features that should spawn convection across the eastern Dakotas into northern Minnesota. Much of the NWS Twin Cities forecast area is located between both of these regimes, which has resulted in a downgrade in severe weather probabilities from SPC. We cannot rule out a few isolated storms this afternoon and evening given an atmosphere characterized by high PWATs & MUCAPEs of ~2000 J/kg, but the lack of shear present should limit greater coverage of deeper convection. Perhaps the highest threat will be locally heavy rainfall and isolated flooding from any slow-moving storms that develop. Opted to lower PoPs significantly this afternoon through tonight given trends in the REFS/HREF CAM ensembles. We'll monitor observational trends and send short term PoP updates as needed.

With deeper convection forecast to reside to the south across central Iowa and northern regime convection forecast to advance into northern Wisconsin overnight, there remains a level of uncertainty surrounding PoP coverage by daybreak Saturday. This is of course an important forecast window with several Independence Day events set to kickoff tomorrow morning. We collaborated with neighboring offices two lower and cap PoPs around 30 percent tomorrow morning to message the idea that there could be scattered showers/storms around, but that the chances are lower than in previous forecast packages. As has been the case, the amount of convection and associated sky cover over the region tomorrow morning will play a role in the evolution of additional storm chances during the afternoon. A trailing shortwave is progged to dive southeast out of the Dakotas later tomorrow and should combine with diurnal timing to force scattered storms across eastern MN/western WI during the afternoon and early evening. The severe weather threat is low, but gusty winds, frequent lightning, and locally heavy rain will be possible with any storms that develop. We followed trends in the REFS/HREF to boost PoPs to 40-60 percent tomorrow afternoon along and east of I-35 in MN/WI. General idea should be for a decrease in showers/storms over time tomorrow evening, with most areas drying out holiday fireworks displays.

Expansion of a ~588dm ridge into the Upper Midwest will bring a welcomed lull in precipitation chances to close the weekend and begin next week. However, warm and humid conditions will continue. The ridge begins to flatten and will allow for the return of a zonal upper-flow pattern that will send several embedded shortwaves across the northern CONUS starting in the middle of next week. The more active pattern will combine with a moisture-rich atmosphere to feature the return of shower and thunderstorm chances for the second half of next week, as highlighted by the majority of global ensemble members.

AVIATION /06Z TAFS THROUGH 12Z SUNDAY/

Issued at 1235 AM CDT Sat Jul 4 2026

Once remnant showers over far western WI dissipate, no additional storms are expected tonight. We should again see some pockets of fog/stratus form before sunrise, but the presence of a good deal of convective debris leads to lower confidence on just how much fog/stratus we'll see. Having gotten hit by the storms Friday evening, RNH will have to greatest risk for fog if they clear out. Scattered storms will fire during peak heating Saturday afternoon, likely starting around 19/20z, but will be winding down by the time we get to sunset. This is the type of setup prob30s were made for, so that's what we have at all terminals. Only change to the going TAFs was to delay those prob30s by an hour. Outside of thunderstorms, very little wind is expected this period.

KMSP...Confidence is at 100% that we'll see storms Saturday afternoon, but given their scattered coverage, the prob30 works well for this situation. Greatest TS risk looks to be between 22z and 02z.

/OUTLOOK FOR KMSP/ SUN...VFR. Winds N 5-10 kts. MON...VFR. Winds SE 5-10 kts. TUE...VFR. Chc TS overnight. Winds SW 5-15 kts.

MPX WATCHES/WARNINGS/ADVISORIES

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