textproduct: Twin Cities

KEY MESSAGES

- Multiple rounds of showers/storms today, with a chance for some strong to severe storms this afternoon.

- Cooler than normal temperatures continue today with a warming trend through the weekend back to normal.

DISCUSSION

Issued at 243 AM CDT Wed Jun 17 2026

The surface low is currently over the Dakotas early this morning. This low will move into southern Minnesota this afternoon and off to our southeast by this evening. In addition we will see the left exit region of a jet streak overhead as well as a subtle shortwave. This will provide for ample lift. The question is what does the atmosphere do with this lift? More specifically what are the thunderstorm impacts? To start he day we have a LLJ providing some much needed moisture. This has allowed rain showers to develop across the broader region. Looking towards thunderstorms we will need instability and for more organized convection, shear. We will see strong speed shear throughout the day, but the directional shear will be depend on the position of the low. The strongest shear, most typical of supercells, will be ahead of the low. This will move through most of our area during the morning. So we will see the best shear profiles during our minima of instability due to the time of day. So far this morning we have struggled to develop even elevated MU CAPE and therefore thunderstorms. The only area with some MU CAPE has been far southwest Minnesota, but even in SW Minnesota there have not been lightning strikes observed. It is farther west closer to the surface low where strikes have been occurring. So it is seeming increasingly unlikely so see much beyond rain showers this morning for much of the area, it would only be far southern Minnesota where there are chances. Attention then turns to the afternoon for storms chances. Even with the modest warming expected today, this should be enough to get 1000-2000 J/kg of CAPE. The difference here though is we have to more straight line hodographs by this point as the low continues to move east. This wold favor more multicell storms and a lower severe impact as these multicell storms tend to struggle more in these lower end instability setups. The SPC has kept a small hatched hail area in far south central and southeast Minnesota. This is the one area that might still have some directional shear to favor more discrete convection and therefore hail. On a heavy rain front, storm motions are expected to be fast enough that while heavy rain impacts cannot be rules out, it is not a major concern. By the evening the low should be off into eastern Wisconsin or the southern Great Lakes. This will lead to diminishing storm coverage as the source of lift comes to an end.

Behind Wednesday's system Thursday will see high pressure move in bringing us clearing skies. With more of a CAA setup though the sun only bring highs up to around 70 for the day. Friday will see another shortwave move in along the largely zonal flow aloft that we have seen all week. There appears to be enough instability for some thunderstorms as well once we get into the afternoon and evening on Friday. As we head into the weekend our northwesterly zonal flow starts to become more westerly and that will help temperatures warm back up to around normal (highs in the upper 70s). How much we warm still varies with GEPS and GEFS holding warmer the the EPS. GEPS still shows some 80s as we moving into the start of the next week. The EPS does have more rain chances along with cooler temperatures with the GEFS and GEPS looking quite dry. The main period EPS members highlight for rain is on Sunday and that is reflected in the NBM PoPs. However with the great spread between the ensemble systems there is little confidence in this rain at this point.

AVIATION /12Z TAFS THROUGH 18Z THURSDAY/

Issued at 645 AM CDT Wed Jun 17 2026

Initial batch of morning showers is sliding out of eastern MN into western WI. With that in mind, we'll open the 12z period dry across the western/southern MN terminals and prevail with showers at RNH/EAU. Surface low pressure is forecast to deepen as it slides east across central MN into western WI today, which will bring additional rounds of showers, MVFR/IFR cigs, and a wind shift out of the northwest. In addition, we are monitoring thunderstorm potential for the southern tier of terminals (RWF/MKT/MSP/RNH) via PROB30s this afternoon. One other note, strong northwesterly surface winds will be the strongest across southwestern MN, with gusts up to 30kts or so possible at RWF. The weather system will gradually exit to the east this evening and the aviation scenario should improve as winds decrease and VFR conditions return.

KMSP...Morning batch of showers is exiting the area to open the TAF, but there still may be a few intermittent VFR showers this morning. Anticipate MVFR cigs to develop mid-morning ahead of a round of potential thunderstorms early this afternoon. IFR cigs are possible, but felt that confidence was only high enough to drop cigs to low MVFR with the thunderstorm/shower chances later today. Winds shift from out of the southeast to out of the northwest early to mid afternoon.

/OUTLOOK FOR KMSP/ THU...VFR. Wind NW 10-20 kts. FRI...VFR. Chc MVFR/TSRA. Wind W 10-15 kts. SAT...VFR. Wind NW 5-10 kts.

MPX WATCHES/WARNINGS/ADVISORIES

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