FXUS63 KMPX 091940 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 240 PM CDT Thu Jul 9 2026 .KEY MESSAGES... - Scattered diurnal storms are expected Friday and Friday evening across Minnesota. Otherwise, very little chances for precip through the middle of next week. - A long duration heat wave moves in this weekend and continues through most of next week. && .DISCUSSION... Issued at 240 PM CDT Thu Jul 9 2026 It is a pleasant day across the region with warm temperatures near 80, light winds, mostly sunny skies, and low humidity. Some of the more developed CU have formed a few showers across southeast MN and central WI, but these are southeast of the area. Other small clusters of storms exist across ND and the Black Hills of SD - a preview of what is to come Friday across MN with the approach of a weakening cold front. Heights Friday will begin rising steadily. While this generally is not favorable for convection, the cold front and an uncapped 2000-3000 J/kg of SBCAPE will develop during the afternoon across western MN. Scattered thunderstorms are possible during that time. Winds throughout the column will be light, but enough veering should exist to squeeze out 20-30 kts of bulk shear. This may allow one or two storms to become more vigorous and the strongest updrafts could contain some hail. Activity should diminish quickly after sunset and likely before reaching eastern MN and WI. The front will wash out Saturday as the ridge continues to build over the Rockies. H5 heights will already be approaching 600 dam over Wyoming by Sunday morning. The ridge will center itself farther east over the northern Plains and/and Upper Midwest early next week while potentially strengthening to an incredible 601-602 dam. The 00Z ECMWF mean heights break all- time records at 700, 500, and 200 mb across MN and the eastern Dakotas Sunday through Tuesday - signaling a truly historic event. As the previous shift noted, the max observed 500 mb height in our local upper air record is 598 dam. Upper air features alone, this would mean an incredibly intense heat wave. However, lower level features tell a different story. This dichotomy exists due to surface high pressure extending from southeastern Canada and New England westward to the Mid Missouri Valley. A notable weakness in thermal profiles will be present within this corridor. Low level trajectories on Monday show our air mass originating from central/eastern IA and northern MO on Sunday, which is from the surface high. A much more impressive low level air mass will exist over eastern MT and the Dakotas where trajectories are removed from the surface high's influence. Extreme Heat Watches are already in place there. 925 mb temps locally will range from +25C to +29C early next week, signaling highs in the low to mid 90s. In addition, moisture advection from the Gulf will be cut off due to the expansive surface high to our south, so all of the humidity will be locally produced via evapotranspiration. Instead of the mid to upper 70s dew points of a couple weeks ago, we'll likely be in the 65 to 70 degree range this time. So despite the record- breaking ridge overhead, the surface high to the south will likely spare us of a dangerous and historic heat wave, although it will still be hot and humid. Unless the humidity and/or temperatures trend warmer than what is currently predicted, we may be able to escape Extreme Heat Warnings with this event. Thunderstorm chances are nearly zero through Tuesday. Confidence drops off mid to late week as the ridge breaks down and cold fronts begin to advance into the northern U.S. again. && .AVIATION /18Z TAFS THROUGH 00Z SATURDAY/... Issued at 1245 PM CDT Thu Jul 9 2026 Stubborn MVFR cigs are finally clearing at KMKT and KEAU. Diurnal Cu have developed with VFR cigs generally expected through the end of the period. There is a non zero chance for a few scattered showers to develop across western Minnesota late tonight, but confidence is too low to include that at this time. We may see some patchy fog develop thanks to the light/calm winds overnight and have added that to KMKT and our Wisconsin sites. KEAU would have the greatest chance of seeing IFR conditions develop. High clouds move in tomorrow morning with winds slowly picking up out of the southeast by the afternoon. KMSP...No additional concerns. /OUTLOOK FOR KMSP/ SAT...VFR. Wind S 5-10kts. SUN...VFR. Wind SW 5-10kts. MON...VFR. Wind SW 5-10kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...Borghoff AVIATION...Dye