FXUS63 KMPX 180555 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 1255 AM CDT Mon May 18 2026 .KEY MESSAGES... - Severe thunderstorms likely this evening, with the highest risk across southern Minnesota (level 3 out of 5). - Initial storms will have potential for large to very large hail (2-3") and tornadoes. - Individual storms will quickly form into a line as they progress through MN and WI. Significant severe wind (70-80+ mph) will become the primary hazard with brief QLCS tornadoes possible across south-central MN. - Another round of thunderstorms is likely Monday night. Severe thunderstorms are possible across southeast Minnesota & western Wisconsin. && .DISCUSSION... Issued at 124 PM CDT Sun May 17 2026 Today is setting up to have potential to be a higher end day for portions of the Enhanced Risk area. Latest visible satellite imagery shorting plenty of clearing with the low-level cloud deck through much of MN, but especially across the southern portion of the state. A bubbling cu field is beginning to develop ahead of ongoing convection tied to the surface low near the NE/SD state line. Surface winds are largely out of the SE/ESE for MN and western WI, and dewpoints have been steadily increasing through the day so far. The best environment is across southern MN where dewpoints have climbed into the 60s already and plenty of clearing is allowing for efficient daytime heating, priming the environment for intense convection later today. Based on satellite and hi-res model data, we expect timing to be maybe slightly earlier than forecast this morning, but generally along the same timeframe. Supercells and storm clusters will develop across Nebraska and South Dakota during the afternoon (around 3-5pm) and progress slightly northeastward into southwest MN and northern IA (around 6-7pm). At this point, storms will be tied to the triple point and situated in a favorable environment for large to very large hail (2-3" in diameter) and damaging wind gusts (60+ mph). Storms will quickly develop into a line along the cold front and turn into a significant wind (70-80+ mph), QLCS setup with line-embedded tornadoes possible within that Enhanced Risk area (stretching from Redwood Falls, MN over to Owatonna, MN and south). Forecast soundings show increasing low-level shear and humped hodographs in the region ahead of the line, which is also reflected in models like the RRFS and HRRR producing a zone of STP values of 5+ across southern MN. Typically QLCS tornadoes are weaker than supercell tornadoes, so we really want to highlight that there is higher- end potential with today's environment compared to your average QLCS setup. Any tornadoes that develop will likely still be brief, like any typical QLCS setup, though the strength of the tornadoes may be capped at an EF2 level rather than EF1. This is all in general-speak, but the point is that the higher- end environment warrants being prepared for slightly stronger tornadoes than you typically get with linear setups (around here at least). The main time window for this to move through is between 7-10pm. The faster the line develops, the quicker it will move east. To the north of the main line, we should still see a surge of low-level moisture as the low tracks northeast. The overall environment just is not as impressive north of the Enhanced Risk region, due to the limited northern progression of the warm front today. It will be high shear/low CAPE setup for much of our forecast area today, but especially for areas north of the Redwood Falls to Owatonna line. A Slight Risk (level 2/5) remains in place to cover this threat for scattered severe storm potential. The primary hazards will be damaging wind (60+ mph) and large hail (1"+ in diameter). Any high end potential will be limited, including the tornado risk. Storms will move through the western MN to St Cloud, MN region around 6-8pm, the Twin Cities metro and eastern MN around 9-11pm, and eventually progress through western WI around 11pm-1am. The severe threat will begin to decrease as the line progresses into WI given that there will likely be scattered storms ahead the cold front, limiting the environment. The severe threat for Monday continues to decrease, and although there is still a Slight Risk (level 2/5) extending from south- central MN into west-central WI, we expect that region to shift even further southeast after we realize our round of storms this evening. We will struggle to build in any real instability and deep layer shear will become more limited as well. In reality, tomorrow will likely feel like a typical rainy Spring day with cool showers and storms through much of the second half of the day. Isolated chances for severe weather will exist, mainly for areas along I-35 and east during the evening. A much drier, and seasonably cool pattern will set up for the rest of the week. Temperatures on Tuesday will be about 10-15 degrees below average, and we could once again have concern for patchy frost overnight (lows in the mid-low 30s) into Wednesday for areas in west- central MN near Stevens, Douglas, and Todd counties. It won't be until Friday that we see our next notable chance for rain as a shortwave develops over the Northern Plains. It looks to be a slow- progressing pattern that would provide us with additional chances for showers and storms throughout the rest of Memorial Day weekend, though confidence is low at this time. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1244 AM CDT Mon May 18 2026 Thunderstorms impacts & gusty winds up to 30 kts will impact EAU over the next 1-2 hours, but otherwise only an hour or two of light showers are expected at MSP & RNH. Very messy ceilings forecast through sunrise, with guidance wanting to fill in low MVFR to IFR stratus across the area, but some drier air mixing in after the rain ends has temporarily scoured out low clouds across much of the area. I do expect these low clouds to fill back in into the early morning hours, but we could see a few hours of VFR until then. We'll stay dry into this afternoon with low stratus likely sticking around through the day. Ceilings will be borderline MVFR/IFR, with IFR favored during the morning & some slight improvement to MVFR possible during the afternoon. Another round of rain showers arrives this evening, with a few thunderstorms likely from southern Minnesota into western Wisconsin. KMSP...Could see sporadic wind gusts to 30 kts out of the east over the next hour or two as drier air behind the rain creates some turbulent winds. IFR ceilings look likely by sunrise & we'll likely hold on to these low ceilings into the afternoon. SOme improvement to above 1000 ft is likely during the afternoon, but ceilings could drop to IFR again tomorrow evening. Timing of the next round of rain looks to begin a as rain showers around 6-7 PM, with the best chance for some thunder between 9 PM to midnight. Scattered rain showers will continue on & off into early Tuesday morning. /OUTLOOK FOR KMSP/ TUE...MVFR cigs becoming VFR. Wind NW 10-15G25kts. WED...VFR. Wind lgt and vrb. THU...VFR. Wind SE 10G20kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...BED AVIATION...ETA