907 FXUS63 KDVN 082321 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 621 PM CDT Tue Jul 8 2025 .KEY MESSAGES... - There is a daily risk of isolated to scattered showers and thunderstorms (20-30%) that will be most favorable in the afternoon and early evening. Thunderstorms Thursday night will have the potential to be stronger as a cold front moves into the area. - Seasonal temperatures and humidity levels will continue through the weekend and into early next week. && .SHORT TERM /THROUGH WEDNESDAY/... Issued at 228 PM CDT Tue Jul 8 2025 A weak swirl in satellite imagery denoting a low in eastern Iowa will slowly exit the area tonight. The weak low should be enough to generate a round of diurnal showers and storms with the better coverage east of the Mississippi. Convection that develops will slowly dissipate with sunset and leave the area dry overnight. The light winds and low level moisture will result in a conducive environment for patchy fog to develop. Cloud cover will the key as to where and how large the areal coverage of any fog will be. After a dry Wednesday morning, isolated diurnal convection is expected to develop during the afternoon with dissipation shortly after sunset. Areal coverage of the diurnal convection will be low, 10% at best, so a vast majority of the area is expected to remain dry. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... Issued at 228 PM CDT Tue Jul 8 2025 Wednesday night/Thursday Assessment...medium (40-60%) confidence on rain potential Diurnal convection from Wednesday afternoon will dissipate after sunset leaving much of Wednesday night dry. Internally, however, the models are suggesting an organized storm complex developing in the northern Plains that will move southeast through western and central Iowa during the night. Although low, the potential is there for some convection west of I-380/U.S. 218 toward sunrise Thursday. The model consensus currently has a 20% chance of that occurring. If convection does move into the area prior to sunrise Thursday, which is dependent upon the timing of the decaying storm complex, then areas generally south of an Independence, IA to Galva, IL line would be favored for remnant isolated to scattered (20-35%) convection during the morning. Boundaries left over from the nocturnal convection will be the focus for isolated to scattered (20-30%) diurnal convection Thursday afternoon. Thursday night through Friday night Assessment...medium (40-60%) confidence for showers and storms Strong convection is forecast to develop along a cold front in the Plains into western Iowa Thursday afternoon. This convection will move into eastern Iowa after midnight and will be in a weakening phase. While there is a risk of severe storms late Thursday night, it is currently a marginal risk (level 1 out of 5) with wind being the primary risk. The cold front will move through the area Friday into Friday evening. Cloud cover will be a factor for the areal coverage on any storms. Isolated to scattered (20-30%) coverage is expected Friday morning from the decaying convection. Boundaries from the overnight convection combined with the cold front will develop a new round of storms Friday afternoon and evening. Interestingly, CSU machine learning is depicting a severe risk for Friday afternoon/evening for the area. The overall signal is weak so it will be interesting to see how this will evolve over the next few days. Given the weak signal, a potential marginal risk (level 1 out of 5) may eventually be possible. Saturday through Tuesday Assessment...medium (40-60%) confidence for showers and storms Typical mid-summer heat and humidity will be seen across the area Saturday through Tuesday with a daily risk of showers and storms. The model consensus has a distinct diurnal nature to the pops with areal coverage being 20-30% for the area. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 616 PM CDT Tue Jul 8 2025 The vast majority of scattered thunderstorms have now moved east towards central Illinois, while a few very isolated showers and weak storms remain over northern Iowa and Wisconsin. These isolated storms could move into eastern Iowa through sunset, but coverage is so low (under 10%), that we`ll leave TAFs dry this evening. Overnight and early Wednesday, shallow fog formation appears to be the main concern, especially in areas that saw recent rainfall, which is mostly Cedar Rapids and Dubuque. This fog, should burn off quickly after sunrise, with VFR conditions and light northwest winds returning to the area. For now, I`ve gone with MVFR 5SM fog at MLI and BRL, and 3SM IFR at CID and DBQ in a temporary condition from 10-13Z. If shallow dense fog does form, an update for LIFR conditions would be warranted. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...08 LONG TERM...08 AVIATION...Ervin