593 FXUS63 KDMX 301949 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 249 PM CDT Mon Aug 30 2021 .DISCUSSION.../Tonight through Monday/ Issued at 247 PM CDT Mon Aug 30 2021 Take Home Points: *Showers/storms move in from W/NW tonight *Seasonable temperatures through the week *Shower/storm chances return late week Discussion: Quiet weather prevailed across the region this morning and afternoon with seasonable temperatures into the lower 80s by early to mid- afternoon. Visible satellite depicted blossoming fair weather cumulus over roughly the southwest third to half of the state, outlining areas of general moisture return and dew points into the low to mid 70s. The primary forecast concern revolves around PoP trends and any strong/severe potential in storms slated to affect the CWA tonight into Tuesday. Overall, there is little notable change in the forecast and thoughts. Initial convection is expected to blossom over areas of north- central Nebraska and South Dakota later this afternoon/evening as a shortwave moves across the region and then track E/SE. The greatest severe threat will remain along/west of the Missouri River where the CAPE/shear profiles and mid-level lapse rates are more favorable and suggestive of potential organization and stronger hail/wind threats. The further you work into Iowa, less favorable mid-level lapse rates, MUCAPE, and deep shear suggest ongoing weakening of any MCS/bowing segments that cross the Missouri River. The main risk with any remaining strong/severe storms will be wind related. Lapse rates and struggle for organization will limit any hail threat. The most likely track for storms continues to be from roughly NW to SE along/near a line from Storm Lake through Des Moines and Ottumwa, where the CAPE gradient is expected to set up. While PWats will be in the 1.75 to 2 inch range, hydrologic issues are not anticipated with generally progressive storms and lack of strong moisture flow into the area. A localized 1 to 2+ inches will be possible, but again, not expected to cause any hydrologic issues. Activity will continue to weaken and slide SE through the day, yielding a quiet Tuesday afternoon/evening. There is a low end chance at a few showers again Tuesday evening along potential hung up surface boundary, but appears most likely to remain west of the area and will be dependent in part on storms tonight. Brief upper level ridging will work through the region, but will be devoid of much in the way of warming or moisture return with the source region being driven by surface high planted over the western Great Lakes. As a result, temperatures will continue to be seasonable in the upper 70s to mid 80s for most. Ending the week, shower/storm chances will return as an upper level trough moving through Canada flattens the upper ridge and a shortwave trough moves off the Rockies and induces Lee Cyclogenesis. Synoptic guidance remain in fair agreement on precipitation and frontal timing, but have slowed just a bit over previous runs, yielding PoPs mainly Thursday evening into Friday. The threat for strong/severe continues to look to be on the lower end with limited depicted CAPE. Additional showers appear possible through the weekend with multiple shortwaves depicted within synoptic guidance, but details vary too widely to make any discernible forecast alterations from initial guidance. && .AVIATION.../For the 18Z TAFS through 18Z Tuesday afternoon/ Issued at 1242 PM CDT Mon Aug 30 2021 Little concern through the first half of the TAF period with VFR conditions prevailing. Around/after 06z, showers/storms are expected to move into western Iowa and track to the SE. KFOD/KDSM are most likely to experience TAF reductions, but have kept mainly VCTS mentions for the this issuance with some uncertainty on track/impacts that far east. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Curtis AVIATION...Curtis