980 FXUS63 KDMX 271710 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 1210 PM CDT Tue Oct 27 2026 ...Updated for the 18z Aviation Discussion... .KEY MESSAGES... - Showers tapering off through the day, with a low (30%) chance for an isolated shower this afternoon across central Iowa. - For Wednesday's storm chances, a few strong storms are possible and and a severe storm or two cannot be completely ruled out. - Temperatures remain seasonal if not above normal through the next week. && .SHORT TERM /THROUGH WEDNESDAY NIGHT/... Issued at 231 AM CDT Tue Oct 27 2026 The 500mb ridge which Iowa was on the periphery of has begun to translate to the east, leading to an area of light showers which have moved into portions of west central and central Iowa. Through the morning, the shortwave providing forcing for these showers will pivot out of Iowa, leading to fairly dry conditions through much of the day. That being said, a few light showers are possible across portions of central Iowa due to residual moisture and decent saturation in the midlevels. Forcing will be hard to come by as the shortwave will no longer be over the area, and there is a fair bit of dry air closer to the surface. PoPs have been kept at or below 30% through today to account for this, with the most favorable area for a shower or two being north of I-80. For areas that won't receive any rainfall, cloud cover is still expected through much of the day, which will keep temperatures contained to the low 70s. Tonight is expected to be dry as we we wait for the next shortwave to enter the region. Aforementioned cloud cover is still expected to linger into the night, leading to above-normal lows in the upper-40s (north) to mid-50s (south) compared to seasonal values of low-30s (north) to upper-40s (south). Our next shortwave is progged to arrive later in the day on Wednesday. The warm sector will be wide open allowing temperatures to climb into the 70s statewide, with southern Iowa seeing temps in the upper 70s. This shortwave will have an associated surface cold front with it, and will manage to kick off showers and even a couple of thunderstorms as it passes through. MUCAPE values of 1000- 1250J/kg are being modeled across the state, though this quickly tapers off as the evening goes on. Furthermore, 35-40kts of 0-6km shear look to be present at the same time. A quick look at sounding profiles show some amount of capping is in place. At this time, given the limited CAPE and potential capping, widespread severe weather is not expected, though an elevated hailer or two could form with more jiggy updrafts. The cold front is expected to move across the state through the night, with any showers and storms clearing out by sunrise Thursday morning. && .LONG TERM /THURSDAY THROUGH MONDAY/... Issued at 140 PM CDT Mon Oct 26 2026 Any storms are expected to have ended by sunrise Thursday morning as the front clears the forecast area stalling just south of Iowa. After a short dry period Thursday, this boundary will lift back northward over the state as low level theta-e advection ensues Thursday night into Friday ahead of the next southern stream shortwave. The shower and storm chances will be prolonged Friday into at least Saturday, though there are likely to be some breaks. Further, will need to monitor diurnal ranges as highs may be too high and lows too low in the cloudy and damp period. Even if temperatures were lowered now, they would still be seasonal as typical late October highs are in the upper 50s to around 60 degrees. With the southern stream wave lifting over Iowa on Sunday, this may bring some drier conditions back over the state late in the weekend. By early next week, a few deterministic models are more amplified or negatively tilted with a trough approaching the region; however, ensembles and AI guidance are generally lower amplitude and less wound up. The takeaway is that a trough of some variety and tilt will be moving through the region early next week and this should spur a continuation of more active weather/shower and storm chances Monday into Tuesday. Confidence in any details beyond this are low at this time. && .AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/... Issued at 1206 PM CDT Tue Oct 27 2026 Main challenge this issuance is the MVFR/IFR cigs across the region. Clouds will continue to focus over northern Iowa through the period, but have trended more towards MVFR in the extended due to cloud coverage remaining steady state so far today. Rain will taper of with low confidence in vsby restrictions over the next 6 hours. VFR conditions are expected at KALO/KDSM/KOTM through this TAF period. Winds will become uniform out of the south and exceed 10kts after 15z. && .DMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...67 LONG TERM...Ansorge AVIATION...Jimenez
