Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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928 FXUS63 KDVN 152319 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 619 PM CDT Sun Sep 15 2024 .KEY MESSAGES... - Temperatures 5-10 degrees above normal through next weekend with mainly dry conditions. - Confidence on rain late this week and weekend continues to lower with a potential blocking pattern developing over the eastern CONUS. && .SHORT TERM /THROUGH MONDAY/... Issued at 221 PM CDT Sun Sep 15 2024 Isolated showers/sprinkles or even a thunderstorm are expected to develop during peak heating this afternoon and dissipate with sunset. Satellite shows developing cumulus mainly west of the Mississippi and roughly concentrated in the I380/highway 218 corridors. Trends with the RAP have been pointing to this area for possible diurnal convection late this afternoon. Areal coverage of any convection that develops this afternoon looks to be lower than yesterday so a majority of the area will remain dry but somewhat humid. After sunset quiet but somewhat humid conditions will be seen across the area. Another warm and somewhat humid day will be in store for Monday. Although the signal is quite weak, another round of isolated showers and possibly a thunderstorm may occur west of the Mississippi during peak heating Monday afternoon. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... Issued at 221 PM CDT Sun Sep 15 2024 Monday night through Thursday Assessment...high confidence on above normal temperatures If diurnal convection develops Monday afternoon it will quickly dissipate with sunset leaving the area dry overnight. Otherwise the upper level high retrogrades into the area which will keep the area dry for much of the work week. IF a rogue SHRA/TSRA would develop during peak heating during the afternoon hours, coverage would be 5 percent or less of the area. Thursday night through Sunday Assessment...high confidence on above normal temperatures. Low confidence on rain chances NHC probability guidance indicates Helene will have likely developed earlier in the week and be a remnant low over the southeast CONUS by late week. The system will help create a blocking pattern over the eastern CONUS while a deep trof develops over the western CONUS. The net result will be near meridional flow over the central CONUS which will cause systems ejecting from the western trof to move more north than east. This then raises the question regarding rain chances from Thursday night into next weekend. The trends with the QPF from the models and more of the ensemble members has been to back off on the potential rainfall. Pops have continued the trend of dropping but not as much as yesterday. Thus the confidence on seeing any rainfall late this week and next weekend is low. Thus the model consensus does have 20-40 percent pops west of a Freeport, IL to Quincy, IL from Thursday night through Saturday with the better chances west of the Mississippi. However, with a potential blocking pattern setting up I would not be surprised to see the rain chances gradually lower during the week. As for Saturday night and Sunday the model consensus has 20-35 percent pops for the entire area with the higher pops west of the Mississippi. These pops continue the overall trend of going lower compared to yesterday. Additionally, the predicted rainfall is also lower as well which raises questions regarding the potential for rain next weekend. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 615 PM CDT Sun Sep 15 2024 VFR will continue tonight into Monday with light E to SE winds and dry conditions. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...08 LONG TERM...08 AVIATION...Uttech