


Area Forecast Discussion
Issued by NWS Des Moines, IA
Issued by NWS Des Moines, IA
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
753 FXUS63 KDMX 112345 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 645 PM CDT Fri Jul 11 2025 ...Updated for the 00z Aviation Discussion... .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 /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 640 PM CDT Fri Jul 11 2025 Remnant IFR/MVFR TSRA will continue to clear from west to east especially for DSM and OTM sites over the next couple of hours. Sites farther north and west have lingering MVFR/low VFR cigs which are expected to remain in place throughout this evening. Another round of SHRA/TSRA was hinted in latest CAMs approaching for FOD but was not confident on coverage overnight as the environment only continues to decay for convective support. IFR/LIFR fog is possible late tonight for most sites but should mix out around 12-14z tomorrow morning. Cigs and vsby improve to MVFR late morning and then VFR by early afternoon. Light and variable winds will shift northwest and becoming breezy with gusts near 20kts for the northern sites. && .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/Dunleavy HYDROLOGY...MPX