Area Forecast Discussion
Issued by NWS Des Moines, IA
Issued by NWS Des Moines, IA
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729 FXUS63 KDMX 092353 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 553 PM CST Sun Nov 9 2025 ...Updated for the 00z Aviation Discussion... .KEY MESSAGES... - Breezy this afternoon, with north northwest winds gusting to 30-35 MPH, before diminishing this evening. A few lingering flurries, with a chance of snow showers in eastern Iowa. - Dry and quiet from Monday through Friday, with steadily warming temperatures reaching the 60s by late in the week. && .DISCUSSION... Issued at 153 PM CST Sun Nov 9 2025 An elongated 500 MB trough currently stretches from just east of Hudson Bay down to Wisconsin, with one lobe of vorticity rounding its southwestern lobe over extreme eastern Iowa and adjacent Wisconsin/Illinois tonight. At the surface, the low pressure center that crossed our region yesterday has moved eastward into the Great Lakes, while a ridge of high pressure is building down the Dakotas and High Plains this afternoon. The pressure gradient between these two systems is producing breezy north northwest winds across Iowa, augmented by cold air advection enhanced by the approach of the aforementioned mid- level trough. Wind gusts to 30-35 MPH will be the norm for a couple more hours before winds gradually abate this evening and tonight. Meanwhile, satellite imagery depicts areas of low stratocumulus clouds moving southward from Minnesota, with a few sites are reporting associated flurries. The cloud depth is shallow without much moisture indicated by soundings, so no accumulation is anticipated and will maintain isolated flurries in the forecast accordingly. This evening into early tonight, as the lobe of vorticity aloft swings by near the eastern Iowa border, several short-range models do show the development of weak instability and higher potential for brief relatively intense snow showers, however, all indications are that this potential will remain just east of our forecast area. We will be monitoring in case any such snow showers do impact our eastern counties, but even then no real accumulation would be anticipated and the primary sensible effects would be briefly reduced visibility. One other fly in the ointment for tonight`s forecast is temperatures. The northwestern sections of our service area have fresh snow cover on the ground and winds will be diminishing overnight, with is a classic setup for temperatures bombing after sunset. However, this potential will be mitigated by at least intermittent cloud cover as well as the fact that while winds will be lighter overnight, they will still be organized and not calm. Nevertheless, have taken forecast hourly and minimum temperatures down a couple of degrees over the snow pack to account for potentially more efficient radiational cooling. On Monday the 500 MB trough will begin to move away eastward, placing Iowa beneath generally west northwesterly steering flow for most of the coming week. With the High Plains surface ridge translating eastward over the Midwest on Monday it will remain cool, but with much lighter winds and mostly sunny skies. Thereafter, the ensuing synoptic pattern will lend itself to alternating periods of brief surface ridging/troughs, with steadily moderating temperatures and little to no chance for additional precipitation. By the end of the week many areas will see highs in the 60s. However, on Friday a deep 500 MB trough will be digging over the western U.S., subsequently migrating eastward, and will likely bring a return of precipitation chances sometime around the end of the week or next weekend. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 556 PM CST Sun Nov 9 2025 Impacts continue to lessen at area terminals as breezy northwest winds to gradually decrease at all terminals through the first several hours of this TAF cycle. Area of 3000-4000 feet stratus deck splits Iowa from NW-SE from SW Minnesota to SE Iowa. This puts KFOD and KOTM right on the edge of thickest clouds, more SCT-BKN west for KDSM. Expect these levels to remain steady - generally in lower VFR. There is an outside chance, that CIGS could drop into MVFR briefly, but confidence isn`t high enough to include in the TAF at this point. Will continue to monitor closely. Otherwise, clouds will gradually lessen after 06z, becoming more mid-high level for Monday. && .DMX WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Lee AVIATION...Hahn