Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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766 FXUS63 KDVN 201723 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1223 PM CDT Fri Sep 20 2024 .KEY MESSAGES... - Above normal temperatures through Saturday then at or slightly below normal temperatures next week. - The weather pattern will remain active over the weekend and into early next week with several chances for rain. && .SHORT TERM /THROUGH TONIGHT/... Issued at 225 AM CDT Fri Sep 20 2024 Weak frontal boundary with isolated to scattered convection will push east of the Mississippi by sunrise and clear the area by mid- morning. Most areas are expected to remain dry through sunrise. Otherwise expect another day of well above normal temperatures for Friday with somewhat humid conditions. Peak afternoon heat indices will be in the mid to upper 80s. Tonight will be mainly dry for the area as return flow brings moisture back into the area ahead of an approaching weak storm system. Far northeast Missouri and parts of southeast Iowa may see isolated to scattered convection (20-30 percent) moving into the area a few hours prior to sunrise Saturday. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Issued at 225 AM CDT Fri Sep 20 2024 Saturday through Monday night Assessment...medium confidence on rain chances The global models shows the upper low over the western CONUS ejecting into the Plains over the weekend with at least two weak storm systems moving through the area. While there are some timing differences between the models, both the deterministic and ensemble runs paint some QPF across the area in the Saturday through Monday night time frame. Now this will not be a washout. There will be many hours of dry weather. However, the timing differences suggest continuous pops from Saturday through Monday night. The model consensus does appear to be targeting two different time frames as the most likely for rain; late Saturday night into Sunday morning and late Sunday afternoon/night. Here the model consensus has 70-90 percent rain chances (Saturday night/Sunday AM) and 50-70 percent rain chances (Sunday afternoon/night). Outside of the suggested prime times for rain, the model consensus generally has 30-40 percent rain chances (Saturday and Monday/Monday night). Tuesday through Thursday Assessment...low to medium confidence on dry conditions. Medium to high confidence on temperatures at or slightly below normal. The model consensus has dry conditions across the area with at or slightly below normal temperatures. The global models generally agree that an upper low will develop across the eastern CONUS but disagree on where it will form. The ECMWF develops the upper low over the Great Lakes and keeps it there into the following weekend. The CMC develops it in the central Plains and slowly moves it into the Midwest. The GFS develops it over the upper Midwest and drops it southeast into the Ohio Valley. The ECMWF solution would be more supportive of mainly dry conditions across the area. THe CMC/GFS solutions would suggest periods of dry conditions but with the potential for diurnal cycles of showers and possibly a few thunderstorms. IF the CMC/GFS solutions end up being correct then low pops (20-30 percent) would be appropriate during the afternoon and early evening hours of Tuesday through Thursday. The overall theme of at or slightly below normal temperatures is reasonable given the proximity of the upper low to the area. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1223 PM CDT Fri Sep 20 2024 VFR conditions are expected throughout the TAF period. Some high cirrus clouds will gradually filter into the region through Saturday morning. Light and variable winds tonight will turn more south to southeasterly and strengthen to around 10 knots. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...08 LONG TERM...08 AVIATION...Schultz