072 FXUS63 KDMX 100821 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 321 AM CDT Wed Aug 10 2022 .DISCUSSION.../Today through Tuesday/ Issued at 321 AM CDT Wed Aug 10 2022 Key Messages: -Tranquil but warmer today. -Increasing threat of isolated to scattered storms late tonight thru Thursday and into Friday morning, mainly northeast half of CWA. -Very warm to hot this weekend with limited precipitation threat. Another quiet overnight with surface ridging across eastern Iowa providing clear skies and light winds over the state. Once again, localized patchy fog has developed but remains limited in extent so far early this morning. There is likely to be some increase in coverage over the next couple of hours, but nothing too extensive at this point prior to sunrise. Otherwise, thermal ridging to the northwest passes into the state today with a continued increase in high temperatures. This is expected to be most pronounced south of Interstate 80 where persistent dry conditions and increasing drought should lead to less evapotranspiration and hence less moisture in the air allowing the airmass to warm slightly better equating to higher temperatures there - especially along the Highway 34 corridor. By tonight, a weak boundary becomes established from northwest to southeast Iowa with some increasing clouds northeast of this boundary. Some elevated weak convergence increases across the north by late tonight with the threat of isolated convection prior to sunrise and low PoPs have been added. This boundary remains somewhat static into Thursday with a subtle shortwave dropping southeast through MN and WI. This is expected to support isolated to scattered convection across portions of central into eastern Iowa during the day. At this time, shear and instability are both relatively weak with the threat of severe weather remaining limited. Some locally heavy rainfall remains possible with the storms, but outside the heavy rain area in the far north from this past weekend, the rainfall should not be problematic and in most areas, actually welcomed. The far south and west are expected to remain quite warm with highs approaching 90 once again where sunshine should be most prevalent. Farther northeast, highs may languish in the upper 70s to low 80s given more extensive clouds and light east surface flow. The boundary is expected to push north and east on Friday with any precipitation threat limited to the far north and east, mainly early in the day. Temperatures remain cooler in the northeast with clouds lingering but the southwest should heat back up with thermal ridging pushing back toward the state during the day. This ridge slides across the state on Saturday ahead of an approaching boundary as the upper ridge flattens across the upper Midwest. Highs are expected to be well into the 90s by Saturday afternoon over the southwest half of the area - once again helped by the drier conditions in this area. The boundary passes through the state with little fanfare late Saturday into early Sunday with the bulk of forcing and associated lift to the northeast of the state. This boundary provides little relief to temperatures in the southwest on Sunday with readings once again into the 90s although cooler air does arrive in the northeast to moderate highs there. Another wave moves along the boundary Sunday night into Monday morning with some limited threat of storms during this time. Otherwise, cooler air gradually deepens across Iowa into next week with below normal readings expected by the middle of the week. It also appears the best threat for rain drops south of the state during the week as the surface boundary pushes farther south with time. && .AVIATION.../For the 06Z TAFS through 06Z Wednesday night/ Issued at 1130 PM CDT Tue Aug 9 2022 Fog possible in eastern terminals before sunrise. Likely only patchy fog at KMCW so left only minor visby reduction. VFR through the period otherwise. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...Cogil AVIATION...Cogil/Jimenez