561 FXUS63 KMPX 120604 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN Issued by National Weather Service Duluth MN 104 AM CDT Thu Jun 12 2025 .KEY MESSAGES... - Chance for a strong to severe storm or two across southern MN this afternoon. Damaging wind and large hail are the primary concerns. - Multiple rounds of rain continue through Friday afternoon. Rainfall totals of 1-2" most likely, with upwards of 4" possible. - Brief break for the weekend before near daily shower and storm chances arrive late Sunday through the end of the period. && .DISCUSSION... Issued at 139 PM CDT Wed Jun 11 2025 Today/Tonight...A narrow band of rain showers driven by 700mb frontogenesis has persisted across central Minnesota for much of the day. Low-level dry air north and south of the boundary has worked to keep things mostly dry, with even a few peeks of sun (especially across southern MN). Water vapor imagery captures the eastward movement of a wave moving out of the Dakotas amid zonal flow aloft. A line of showers and thunderstorms has developed ahead of the wave and is advancing east into western Minnesota this afternoon. PoPs are greatest along and south of I-94, though the best chance for thunderstorms will be closer to I-90. SPC mesoanalysis captures the position of the instability gradient positioned across far northern Iowa. As the line/complex of showers and thunderstorms moves east, the southern-most convection rooted along the instability gradient will pose the greatest risk for an isolated damaging wind gust or instance of large hail. This is reflected by SPC`s Day 1 Marginal Risk area. A Slight Risk was added along and south of the state border, where a more potent environment exists. Thursday...The main batch of convection will move east/southeast this evening, however showers and a few storms may linger across southern Minnesota overnight as the low-level jet intersects the stationary frontal boundary near the MN/IA border. By daybreak Thursday, the next upper-level shortwave of interest if forecast to eject over the northern Great Plains, which will support the development of a surface low across the Dakotas. The increase in warm advection east of the surface low will push the aforementioned stationary boundary north into southern Minnesota tomorrow. CAMs depict multiple rounds of scattered showers and storms moving from northwest to southeast along the boundary through Thursday afternoon and evening. Similar to today, the best chance for a strong to severe thunderstorm will be with any convection rooted near the instability gradient, which will align with the position of the stationary boundary. Given the forecast northward progression of the boundary, the Day 2 severe weather outlook features a larger Marginal Risk that spans most of central/southern Minnesota and a portion of western Wisconsin. Once again, looking at isolated instances of damaging wind or large hail with stronger cells. However, cannot rule out an isolated spin-up (best chance with any discrete cells across southern MN). Thursday Night/Friday...The approach of the surface low Thursday night will work in tandem with the strengthening low-level jet to set the stage for the for what will likely be the most widespread round of heavy rain over the next few days. Factor in the influence of both Pacific and Gulf moisture, a transient but notable frontogenic component, and the west to east orientation of the mid- level frontal boundary and the pieces are in place for a longer duration heavy rain event with training likely. We have noted a northward shift in the heaviest rain axis across the guidance over the past 36 hours and the 12z guidance has generally continued that theme. There are two "camps" that are becoming apparent in the guidance, one that features a muted northward progression of the mid- level front and the other that displays the heaviest precipitation axis north of I-94 across central MN. The reality is that it`s tough to say which camp will be correct, which is why WPC continues to display a large Slight Risk ERO across all of central and southern MN. Would tend to think solutions that display the "stair-step" idea starting with todays round of QPF across southern MN/northern IA, tomorrow`s convective round across southern MN, and the Thurs PM/Fri AM round across central MN would fit the conceptual model given the anticipated northward movement of the boundaries and theta-e rich air over the next 72 hours. Confidence is lower with the convective nature of the precipitation (thus rainfall rates) in the northernmost solutions given that the better instability is forecast to be displaced to the south. So...with all of this in mind, how much rain can be expected for my hometown? Confidence is high in 1"+ rainfall amounts between now and Friday afternoon at just about all locations across the MPX coverage area. 3-day totals between 1-3" are likely, with localized totals approaching 4"+ on the table if multiple rounds of rain can train over the same area. Should trends in the guidance come to fruition, this zone will likely on the northern extent of tomorrow afternoon/evening`s round of convection and the southernmost extent of the late night batch of heavy rain. (In other words along/north of I-94 per the 12z guidance) Additional shifts are possible and will be able to lean more on the hi-res guidance in forthcoming forecast periods. Weekend & Beyond...Dry weather returns to open the weekend, as an upper ridge axis shifts east over the northern CONUS. Temperatures will be cooler following the multi-day rainy period, with highs in the upper 60s/near 70 on Friday and Saturday. Latest NBM captures warming back into the mid to upper 70s Sunday, with warm advection supporting highs in the low 80s next week. Active weather returns early next week as multiple shortwaves eject eastward from western troughing. We have daily 30-50% chances for showers and thunderstorms as a result of the forecast pattern. It`s too soon to discuss specifics, however next week looks quite unsettled with an increase in ML severe weather probs through the middle of the week. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1253 AM CDT Thu Jun 12 2025 Showers southeast of the TAF sites this morning, but expect them to lift north today and tonight. Vis reductions due to smoke and local fog this morning before rain becomes more prevalent though the afternoon. Thunderstorm potential increases this evening into the overnight hours. KMSP...Haze/smoke is possible this morning with some smoke and lower visibilities around. Shower activity will remain south of KMSP this morning, but activity will begin to return this afternoon. More robust thunderstorm activity is possible tonight, but models outlooks have a lot of variability with the location of showers and thunderstorms today. The best chance currently is to the north of KMSP. /OUTLOOK FOR KMSP/ FRI...RA/MVFR likely, chc TSRA/IFR early. Wind ENE 5-10 kts. SAT...MVFR clouds/-RA with IFR possible early, then VFR. Wind E 5-10 kts. SUN...VFR with MVFR possible. Wind SE at 10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...Strus AVIATION...Wolfe