


Area Forecast Discussion
Issued by NWS Des Moines, IA
Issued by NWS Des Moines, IA
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225 FXUS63 KDMX 111928 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 228 PM CDT Fri Jul 11 2025 .KEY MESSAGES... - Today, thunderstorms this afternoon will be capable of producing heavy rain, damaging wind, and a few tornadoes, especially areas east of I-35. Please remain weather aware, and never drive through flood waters. - This weekend, drying out with additional rain chances Tuesday and Wendesday. - Late next week, cooler temperatures arrive for Thursday and Friday. && .DISCUSSION... Issued at 147 PM CDT Fri Jul 11 2025 TODAY...Thunderstorms capable of heavy rain, damaging wind, and event a few tornadoes are expected this afternoon and evening. Early afternoon satellite and radar imagery shows storms across much of the region as of 2PM. For the rest of today, multiple rounds of storms could lead to heavy rain and flooding. There is also a severe weather threat with these storms, with damaging wind and a few tornadoes being the primary threat. A weak surface low was centered across southern Iowa, with southeast winds ahead of it.Temperautres were in the mid 80s, with dewpoints in the mid to upper 70s. This warm and unstable airmass will be the main driver for thunderstorms today, while upstream an upper level wave along the IA/NE border will provide the forcing for ascent. The main question will be how long storms will be discrete in the warm sector, vs how quickly they will grow upscale into a line. This is one of the key factors for whether or not tornadoes or damaging wind will be the primary threat. Even if storms do develop into a line, the low level shear could support QLCS tornadoes, so have a Tornado Watch in effect for mainly the Southeast part of Iowa, including the Des Moines metro. North of this, a severe thunderstorm watch is in effect, where confidence is higher in a wind and/or hail threat. In addition to the severe threat, heavy rain is also a concern given the PWAT values near or above 2 inches. Training storms along an ill-defined warm front could produce rainfall totals of 2 to 3 inches, with a few pockets close to 4 inches based on the local probability matched mean of the HREF. SATURDAY THROUGH FRIDAY...Storms will move east tonight, and the weather will dry out over the weekend and into early next week. The next chance for storms will be Tuesday into Wednesday as a cold front moves through the region. A few storms could be strong to severe, but as of now there isn`t a signal that this will be anything noteworthy. Looking ahead, if the cold front is able to push through, temperatures will cool off toward the end of week, with highs closer to 80s. If it hangs up across the region, then expect continued chances for showers and thunderstorms. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1245 PM CDT Fri Jul 11 2025 Scattered thunderstorms are the main concern for today. Storms are already ongoing, and additional development is expected this afternoon. These storms could produce hail and wind. Did add a mention of wind for KOTM, but KALO and KDSM will have to be watched as well. Storms will move east this evening, with light winds overnight and some patchy fog/stratus possible. Expect MVFR/VFR conditions on Saturday. && .HYDROLOGY... Issued at 147 PM CDT Fri Jul 11 2025 As mentioned earlier in the main discussion, training thunderstorms are the main concern this afternoon, before the storms form into a line and move east this evening. The atmospheric profile is very moist, with PWAT values near 2 inches. Mid level lapse rates of only 5 to 6 C/km, together with high freezing levels will lead to heavy rainfall rates that could cause flash flooding over any urban area. As for the rivers, this rainfall will lead to rises on the rivers, with a few locations seeing Minor flooding. There is a non-zero chance for Moderate flooding, but the overall threat for that category or higher is low. The areas most at risk for flooding are the ones that had the rainfall last night, and the smaller bases that see the heaviest rain would be the quickest to respond. Fortunately this will be the last rainfall event for at least a few days. && .DMX WATCHES/WARNINGS/ADVISORIES... Flood Watch until 1 AM CDT Saturday for IAZ038-039-049-050- 059>062-072>075-084>086-095>097. && $$ DISCUSSION...MPX AVIATION...MPX HYDROLOGY...MPX