053 FXUS63 KDVN 091725 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL Issued by National Weather Service La Crosse WI 1225 PM CDT Tue Oct 9 2018 ...AVIATION UPDATE... .SYNOPSIS... Issued at 355 AM CDT Tue Oct 9 2018 As of 2am, a band of showers and embedded storms was streaming NE across NW sections of Benton and Buchanan counties with a few small showers between Iowa City and Dubuque. Estimated rainfall amounts in the heavier activity were in the 0.50 to 1 inch range. The rest of the CWA has remained dry overnight. Temperatures were in the mid 60s to lower 70s, with dew points in the 60s. && .SHORT TERM...(Today and Tonight) ISSUED AT 355 AM CDT Tue Oct 9 2018 A quasi-stationary front across western IA into SE MN will ever so slowly move into central IA today and tonight as some disturbances ride up along it. It now appears it will finally move through the area Wednesday morning and early afternoon. Have trimmed PoPs back in the near term based on radar trends and some CAMs keeping the SE half dry through midday. This afternoon PoPs gradually ramp up from west to east becoming likely in the NW CWA late this afternoon/early evening. Wind profiles and the moist/unstable air mass will support severe storms late this afternoon well into the night. The SPC has a Slight Risk for areas west of a line from Carthage to Freeport. The main threats will be damaging winds and a few tornadoes. With the ground across the area so saturated, it is conceivable that some sub-severe wind gusts may uproot some trees. In addition, heavy rainfall will still be possible; especially in areas that see more than one round of storms move through. The bulk of the precip will come late tonight into Wed morning. It still appears that some local swaths of 1 to 2 inches is still possible. We have expanded the flash flood watch to include the entire area and extended it until Wednesday early afternoon. Temperatures today will once again be more indicative of summer, with highs in the mid 70s to mid 80s. It will still be humid as well. Lows will be in the 60s. .LONG TERM...(Wednesday through Monday) ISSUED AT 355 AM CDT Tue Oct 9 2018 Wednesday afternoon, the front will sweep though the area replacing the rainy conditions with gusty west winds and falling temps. Temperatures will be falling through the day, with mid 40s and 50s by the evening commute, with slightly colder wind chills. Thursday, cold and blustery conditions are expected with highs in the mid 40s to lower 50s. By Friday morning, lows will be in the low to mid 30s. Highs Friday will only be in the 40s. Saturday afternoon into Monday, a system lifts out of the southwest phasing with a clipper from the northwest. This brings rain back into the forecast for Sat through Sun. Another cold shot into early next week, with lows in the 30s again. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon) ISSUED AT 1225 PM CDT Tue Oct 9 2018 Showers and thunderstorms will move across the TAF sites late this afternoon into this evening with MVFR conditions expected and the potential for IFR conditions under any heavier rain. A few storms may be severe mainly west of the Mississippi River with damaging winds and an isolated tornado cannot be ruled out. && .HYDROLOGY... Issued at 317 PM CDT Mon Oct 8 2018 Forecasts for heavy rain in central Iowa to northeast Iowa are continuing, and have not changed much. However, as this event falls into the 48hr QPF that is used to produce river forecasts. With moderate to heavy rain amounts falling last night, especially over northeast Iowa the new rain is combining with the QPF to produce crests that are much higher than issued yesterday. This is due to the process, not because the heavy rain isn't already forecast. For our rivers, the Cedar River is now forecast to see greatly increasing flows by day 2, resulting in a steady rise to 19.7 feet at Cedar Rapids, which is major. The category of major is highly confident, though the exact crest value may change as the we see the rain accumulate / run off. The same is confidence on a significant rise is true for routed water on the Wapsipinicon, Des Moines, Skunk, and Iowa basins. For the Iowa, outflow from Coralville Dam is around 10-11Kcfs. This helping rise Iowa City back to minor flood today, and with some COE variation, it will rise and fall over flood stage the next several days. Just downstream, the English River, which has had it's stage and flow confirmed, is near crest, about 2 feet over major flood status. This is combining with the Iowa River, to bring a continued rise well above major flood near Lone Tree. That Lone Tree major flood status should not drop much for the next 5-6 days. This will continue to bring major flooding down through the lower Iowa basin this week. With all tributaries seeing high level, rises, and in many case major river flooding, and even the upstream portions of the Mississippi upstream seeing heavy rainfall tonight through Tuesday night, the big river will see some very significant rises as well. For now, though minor flooding may be possible from Dubuque through Bellevue, the portions most likely to flood are from Camanche downstream. With the major flooding on the Wapsipinicon and Rock, with high water from the Turkey and Maquoketa, the main stem Mississippi is forecast to reach major flood status from Rock Island, downstream. This resulted in increase flood forecasts downstream where sites were already forecast to reach major flood as well. ERVIN && .DVN WATCHES/WARNINGS/ADVISORIES... IA...Flash Flood Watch from late tonight through Wednesday afternoon for Clinton-Jackson-Scott. Flash Flood Watch from 7 PM CDT this evening through Wednesday afternoon for Des Moines-Henry IA-Lee-Louisa-Muscatine-Van Buren. Flash Flood Watch through Wednesday afternoon for Benton- Buchanan-Cedar-Delaware-Dubuque-Iowa-Jefferson-Johnson- Jones-Keokuk-Linn-Washington. IL...Flash Flood Watch from late tonight through Wednesday afternoon for Bureau-Carroll-Hancock-Henderson-Henry IL-Jo Daviess- McDonough-Mercer-Putnam-Rock Island-Stephenson-Warren- Whiteside. MO...Flash Flood Watch from 7 PM CDT this evening through Wednesday afternoon for Clark-Scotland. && $$ SYNOPSIS...14 SHORT TERM...14 LONG TERM...14 AVIATION...JRW HYDROLOGY...Ervin