Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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746 FXUS63 KDVN 171905 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 205 PM CDT Wed Jul 17 2024 .KEY MESSAGES... - Pleasant and dry conditions tonight, with well below normal temperatures. - Much welcomed dry weather through the rest of the work week and into the weekend. - Moderate to major river flooding continues on the Mississippi River. The Rock River is now expected to see moderate flooding by the end of the week. && .SHORT TERM /THROUGH TONIGHT/... Issued at 205 PM CDT Wed Jul 17 2024 A large 1023mb surface high to move over the Midwest overnight tonight bringing a rather dry and cool airmass to the region. Taking a look at 12z upper air data, the 850mb temp at INL was 6C or near its 10th percentile per SPC sounding climatology. This air will advect into WI overnight tonight, with RAP 850mb temps dropping into 7-9C range locally. This also will be near the 10th percentile of our soundings here at DVN. So long story short, it will be a very nice and cool night for July standards. In fact, with clearing skies and light winds, temperatures and dewpoints will drop into the low to mid 50s. This will be within shouting distance to record lows for the 18th. See climate section below for details. Thursday...surface high to be centered over the region, with some more fair wx Cu developing in the afternoon. Highs will top out in the upper 70s. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Issued at 205 PM CDT Wed Jul 17 2024 Comfortable and dry conditions are expected Friday and Saturday, as surface high pressure drifts east into IN/OH/MI. An upper level wave will drop southeast into the Great Plains Saturday afternoon and evening, bringing an increase in clouds. Better moisture and lift will be just to our west and have kept PoPs below mention through Saturday. The NBM and the LREF 100 member ensemble probabilities of measurable QPF also support this. Small slight chance PoPs in our far western counties are seen Sunday and Monday, as the open upper wave rotates just to our west. Moisture will be the limiting factor. Most of the area should remain dry through the weekend and into next week. Looking ahead, the upper air pattern remains unfavorable for any widespread rainfall. A few weak waves early in the week may bring some chances for rain, but the threat for any strong storms remains low. Temperatures will be near seasonable, with highs in the 80s and lows in the 60s. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1133 AM CDT Wed Jul 17 2024 VFR conditions are expected through the TAF cycle. Some fair weather cumulus clouds will expand across the eastern IA and northern IL this afternoon, but remain SCT above 3kft. Decreasing clouds and winds under 5 kts will be seen after sunset. && .HYDROLOGY... Issued at 1125 AM CDT Wed Jul 17 2024 The Mississippi River has crested at all sites, with some reaches continuing to experience somewhat stalled falls or steady trends over the next few days due to recent bouts of heavy rain, local run- off, and tributary input. L&D 19 at Keokuk and Gregory Landing will even experience secondary rises into the weekend. Tributary Rivers: The recent rounds of heavy rain on the Rock River basin will continue to produce significant rises on the Rock, but after assessing the extent of run-off and upstream flow trends, Joslin and Moline are now projected to remain below the Major flood stage. The Rock at Como will be in Minor flood through Friday evening. The Pecatonica River is projected to rise into Minor flood at Freeport IL Friday night. The lower Wapsipinicon River near Dewitt, IA performed a secondary crest around 11.2 feet yesterday/Tuesday evening, but is now dropping below flood stage. With the dry weather into the weekend, the Wapsi is now expected to remain in the decline mode and remain below the flood stage. Backwater effects from the Mississippi River will keep the lower Iowa River just below flood stage through early next week. Further south, torrential rainfall and run-off from Monday night may produce a large rise to action stage on the La Moine River near Colmar in west central IL by Thursday. But the extent and speed is still somewhat uncertain and will have to watch river rise trends over the next 24 hours. && .CLIMATE... Issued at 205 PM CDT Wed Jul 17 2024 Record Low Temperatures: July 18: KBRL: 53 in 1924 KCID: 49 in 2009 KDBQ: 51 in 1979 KMLI: 54 in 2014 && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Gross LONG TERM...Gross AVIATION...Gross HYDROLOGY...12 CLIMATE...Gross