505 FXUS63 KDVN 091957 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 257 PM CDT Tue Oct 9 2018 ...HYDROLOGY 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 224 PM CDT Tue Oct 9 2018 Main point...one more round of heavy rain is expected tonight into Wednesday. A broad swath of 1 to 2 inches of rain, with locally higher amounts, is expected from central Iowa into southeast Minnesota and Wisconsin. Soils generally north of I-80 and especially across Minnesota and Wisconsin are saturated so any additional rainfall will rapidly run off into area waterways. After sunset Wednesday, the overall weather pattern will change. Rain will still be possible over next weekend but amounts will be much lighter than what has been seen over the past 10 days. As a result of the forecast heavy rainfall, new river flood warnings were issued today for parts of the Cedar, Maquoketa, Mississippi, and Wapsipinicon rivers. Mississippi River... The new forecasts for the Mississippi river show rises occurring all the way through October 16th. With more heavy rain expected across Minnesota and Wisconsin, crests on the Mississippi river will occur October 17th through the 24th. Confidence is high that moderate to major flooding will be seen from LD 14 at Le Claire, IA down through Gregory Landing, MO. North of LD 14, minor to moderate flooding is expected. Iowa Tributary rivers... Routed water is already moving downstream through the basins. With the addition of heavy rainfall through sunset Wednesday, confidence is high that moderate to major flooding will continue along the Cedar, English, Iowa, North Skunk, Skunk, and Wapsipinicon rivers. From Columbus Junction down to the mouth of the Iowa river, the Cedar river will be providing a majority of routed flow that will result in moderate to major flooding. At Iowa City, runoff from creeks and streams below Coralville from the next round of heavy rain and increased releases from Coralville dam will push the Iowa river close to 23 feet by the weekend. Pecatonica and Rock rivers... The heaviest rainfall is not expected to occur in the Pecatonica and Rock river basins through sunset Wednesday. Thus current river forecasts are based on routed flow and predicted rainfall. Confidence remains high that moderate flooding will be seen on the Pecatonica river and major flooding from Joslin to the Mississippi. As the Mississippi continues to rise, the rate of fall on the Rock river is likely to slow down and thus prolong the flooding. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...Flash Flood Watch from 1 AM CDT Wednesday 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 1 AM CDT Wednesday 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...08