FXUS63 KDVN 040533 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1233 AM CDT Mon May 4 2026 .KEY MESSAGES... - The Storm Prediction Center has a marginal (level 1 out of 5) risk of severe storms Monday afternoon/evening for the entire area. Damaging winds and hail are the primary risks. - An omega block on the west coast will keep cooler than normal temperatures across the area Tuesday through Friday with another warm-up for the weekend. && .SHORT TERM /THROUGH TONIGHT/... Issued at 145 PM CDT Sun May 3 2026 Gusty southwest to west winds (25-35 mph) will continue into early this evening before subsiding as the pressure gradient slackens. A dry air mass and generally clear skies will allow temperatures to drop into the mid 40s to lower 50s for overnight lows. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Issued at 145 PM CDT Sun May 3 2026 Monday... A shortwave trough and band of shear vorticity over south- central Canada is expected to dive down into the Northern Plains, retrograding the longwave trough over the Great Lakes to the west. A deepening surface low over southeast Ontario will force another cold front to dive southward into our CWA. Strong southwesterly flow at the surface is forecasted to bring highs back into the upper 70s to low-80s ahead of the front and dew points into the 40s to lower 50s. This will allow for a well- mixed boundary layer and steep low-level lapse rates, supporting 200-400 J/kg of SBCAPE north of I-80 and 500-1000 J/kg south. A capping inversion due to radiation cooling from the night before and the surface front moving well ahead of the upper- level trough should limit convective initiation to the mid-to- late afternoon along the confluence boundary. Thunderstorm coverage is going to aligned with the instability levels: scattered (30-40%) storms north of I-80, with higher coverage of storms to the south (50-70%). SPC has a Marginal (Level 1 out of 5) Risk for severe weather across the entire CWA. Primary threats remain isolated damaging winds up to 60 mph and quarter-sized hail. The limiting factor with this severe event is lack of sufficient low-level moisture return. While confidence is increasing for thunderstorm activity across the CWA, the organization of these storms is still uncertainty and evolving. The cold front will clear the area from northwest to southeast Monday evening into the overnight hours with a strong shift to northerly flow, gusting up to 30 mph. Lows are forecasted to drop into the upper 40s and low 50s. Tuesday-Wednesday night... Cold air advection, northwest flow aloft, and a surface high pressure to our southwest will keep conditions calm after some rain showers south of Highway 34 moves out of the area Tuesday morning. Temperatures are expected to be 5-10 degrees below average with highs in the mid-to-upper 50s and lows in the upper 30s to low 40s. Winds will also be lighter, 5-10 mph during the day and subsiding at night. Thursday-Satruday... The longwave trough axis sitting to the north of us for the first half of the week will finally swing through. While surface forcing is forecasted to be limited, a 500 mb vorticity maximum over Wisconsin and ample mid-level moisture should be sufficient to support light rain showers across much of the CWA Thursday into Thursday night. A westerly wind shift is also forecasted to kick off a warming trend with highs climbing back into the 60s. These showers should move out by Friday morning, leading to a dry start for next weekend with more seasonable highs in the mid- 60s to low 70s. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1231 AM CDT Mon May 4 2026 Winds will remain under 10 knots and back to the southwest through sunrise. Deep mixing during the day on Monday will result in wind gusts over 20 knots resulting in considerable low level mechanical turbulence. A cold front will move into eastern Iowa after 18z/04. Moisture is limited but 10-20% coverage of diurnal SHRA/TSRA is possible through 02z/05. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Uttech LONG TERM...Delaune AVIATION...08