318 FXUS63 KDMX 020337 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 1037 PM CDT Sun Jun 1 2025 ...Updated for the 06z Aviation Discussion... .KEY MESSAGES... - Warm Monday with highs in the mid to upper 80s. - A few strong storms possible Monday night. Additional storms with a slight risk for severe weather on Tuesday over the southeast. && .DISCUSSION... Issued at 254 PM CDT Sun Jun 1 2025 Wildfire smoke moving over Iowa is the main feature over the state today. Some thicker smoke aloft is along and just east of the Interstate 35 corridor this afternoon. The solar filtering by the smoke likely shaved a few degrees off of temperatures today. Otherwise, the upper level ridging continued to move east into the Central and Northern Plains today and will continue to do so tonight though the main thermal ridge will remain west of Iowa into Monday. For tonight, a steep low level inversion will develop just off of the surface a around 900-1000 ft AGL. This will keep light winds over Iowa. Low pressure troughing at the surface and an upper level short wave will approach the region on Monday. This will lead to an increased pressure gradient and a transition to west/southwest flow aloft as the upper ridge passes to the east. This transition from northerly flow will lead to the upper level smoke to disperse off to the east through the day Monday. Mixing by late morning and into the afternoon will lead to gusty south winds as well. The elevated mixed layer (EML) will be stronger on Monday and will keep convective capping in place. High temperatures on Monday will be in the mid to upper 80s. Storms will develop during the afternoon over Nebraska and into southwest Minnesota. Initial storm motions will be east/northeast, while the surface boundary moves very slowly southeast, which would delay the storms arrival into the DMX county warning area (CWA). Also there is the potential for these initial storms to become outflow dominant quickly. Any outflow into the northwest CWA likely would not initiate any organized convection into the early evening. A more organized MCS should develop late evening over Nebraska as the main upper level support arrives. A fractured but still descent low level jet will be pointed into central Iowa after midnight. Organized convection could persist beyond 06z into central Iowa give the instability and lapse rates at around 5 kft and above. If that energy is realized, then a large hail threat will persist. There is a slight risk for severe weather over southeast Iowa on Tuesday. There remains uncertainty on storms in that area as impacts from overnight storms outflow may push this potential even further east. Should surface based storms develop late morning/early afternoon, then there is the potential for damaging winds. Saturating profiles do limit lapse rates and updraft strength, thus a limited hail potential. A localized potential for heavy rain does exist given the window for training storms and an influx of Gulf moisture driving PWATs to 2" plus. Beyond Tuesday, the next chance for storms along with at least a severe threat with elevated storms arrives in the late Thursday/Friday time period, pending the high pressure influence. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1037 PM CDT Sun Jun 1 2025 VFR conditions will remain in place over the period with confidence high through sunset Monday. High level wildfire smoke continues to be advertised as SCT250, but late Monday afternoon into Monday evening this smoke should be pushed to the east. Winds from the south or south-southeast will mainly be around or under 10 knots overnight. Winds will increase through the morning Monday becoming sustained at 10 to 20 knots with gusts of 20 to 30 knots - the highest winds over northern and western Iowa. While there are some indications that a few showers or storms may near MCW or FOD toward the end of the period, confidence is insufficient to include a PROB30 group. && .DMX WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Donavon AVIATION...Ansorge