textproduct: Twin Cities

KEY MESSAGES

- Chances for scattered showers and isolated thunderstorms will continue through Monday.

- Better chance of widespread rainfall arrives Wednesday into Thursday.

- Extended forecast features an above normal temperatures trend through the first portion of June.

DISCUSSION

Issued at 110 PM CDT Sun May 31 2026

It's one of those days where the weather varies quite a bit from west to east across the area! Afternoon radar displays waves of scattered showers (some of which have been very efficient rain producers -- FCM measured 0.4" in one hour!) lifting northward across MN within a region of ascent ahead of an elongated trough that spans much of the NW CONUS. Conversely, dry weather is continues east of the MN/WI state line. Over the past few days, the Upper Midwest has been positioned south of a blocking high over south central Canada in an omega block pattern. We're seeing a slight breakdown of this pattern today, as stronger forcing rounding the trough has resulted in an eastward push of a moisture plume (characterized by PWATs of 1-1.5") that spans from central MN all the way to Gulf. Additional waves of showers are likely this afternoon and evening as synoptic forcing increases. Widespread cloud cover and ongoing showers have worked to slow warming and will likely play a role in lowering chances of thunderstorms later today. However, any additional showers that take on a more convective look will have the potential to produce lightning and efficient rainfall rates given a couple hundred joules of MUCAPE and high PWATs referenced above. We have overhauled the short term grids to better reflect observational trends, which included lowering temperatures and an eastward expansion/increase in PoPs. CAM guidance remains rather messy given the weaker forcing regime, but there is a signal for a band rain/isolated thunder moving from southwest to northeast across the region this evening so have worked that idea into the latest forecast. We'll likely have to refine the PoP windows with several updates through the evening and into the night in this regime.

Large scale blocking will result in the maturation of an upper-low over the northwestern CONUS Monday and the reestablishment of ridging across the Upper Midwest. Forcing for additional showers and thunderstorms will become displaced to the northwest, which has yielded lower PoPs for the opening of the work week. Still, HREF advertises a plume of MUCAPEs on the order of 1000-1500 J/kg across the western half of the forecast area tomorrow afternoon which will work in tandem with PWATS ~1-1.25" to support isolated showers and perhaps a thunderstorm or two. Coverage of precipitation is forecast to be much lower than today/tonight, so we've opted to only roll with 20-30 PoPs in the grids. SPC has maintained a Marginal (Level 1/5) risk area across far southwestern MN where instability is forecast to be the strongest. Isolated damaging wind and large hail are the primary threats. Given the expectation of a drier picture Monday, temperatures are forecast to climb back into the lower 80s for afternoon highs.

Tuesday & Wednesday should be warm and dry for most locations as the ridge axis remains positioned over the region. High temperatures are forecast to climb into the mid 80s both days. A more notable pattern change is set to take place Wednesday PM onward, as the early week omega block breaks down. The development of a strong zonal Pacific jet will send the remnant upper-low (still spinning over the NW CONUS by mid-week) eastward along the International Border. In response, a surface low and attendant cold front will advance across the Upper Midwest and bring widespread precipitation chances to the region. There is strong ensemble support for a widespread precipitation which is reflected by 60-70 PoPs in the NBM forecast grids late Wednesday into early Thursday. We're still putting the QPF forecast together, but confidence is increasing the potential for 0.25-0.75" of rain.

Looking ahead to next weekend, guidance advertises a deeper trough digging over the western CONUS and large scale ridge amplification over the Upper Midwest/Great Lakes. Would tend to like this look for a continued trend of above normal temperatures, which is highlighted with highs in the mid 80s in the NBM. However, global models feature a shortwave or two advancing northeast within large scale southwesterly flow ahead of the western trough which could promote additional precipitation chances. There is at least some support for more measurable precipitation tied to the shortwaves in the ensemble guidance, so that will bear watching. Otherwise, the pattern looks to remain warm through the first portion of the month.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1213 PM CDT Sun May 31 2026

Considerable changes have been made to this TAF regarding precipitation timing. Areas of scattered showers will continue across parts of MN early this afternoon before they push north. Have included TEMPOs for most MN terminals to mention -SHRA with reductions to MVFR cigs. A band of showers will develop from western to southern MN late this afternoon and push north through this evening. Have either included TEMPOs or prevailing mentions for this second round of -RA and MVFR cigs at most MN terminals. The band of rain should stall out and dissipate overnight somewhere from east-central MN into extreme western WI. For AXN, RWF, and MKT, the forecast becomes very uncertain after 06z. Cigs could fall to IFR/LIFR through sunrise Monday if pooling residual moisture can create thick, low stratus within the calm conditions. Currently have AXN and RWF falling to IFR with the inclusion of a PROB30 from 12-15z Monday for a possible third round of -SHRA. VFR cigs become more likely the farther east one goes. Southeasterly winds will gust to near 20 MPH this afternoon over western MN with speeds decreasing east. Winds slow to near 5 knots/variable tonight.

KMSP...Have included TEMPOs from 18-20z and 23-03z for -SHRA and -RA respectively. Visibilities shouldn't fall too much from the rain but MVFR cigs are expected this evening. Rain will end after 03z and VFR should prevail for the rest of the period. Southeasterly winds will gust to near 20 knots this afternoon but slow to 5-10 knots this evening through tonight.

/OUTLOOK FOR KMSP/ TUE...VFR. Wind SE 5-10 kts. WED...Mainly VFR. Chance P.M. -SHRA/MVFR. Wind S 10G20 kts. THU...SHRA likely. Chance TSRA/MVFR. Wind SW 10-15G25 kts.

MPX WATCHES/WARNINGS/ADVISORIES

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