015 FXUS63 KDVN 051727 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1227 PM CDT Fri Jun 5 2026 .KEY MESSAGES... - There is a Slight Risk (Level 2 out of 5) for both severe weather and heavy rainfall tonight across the entire area with a more favored area south of Interstate 80. - After possible scattered storms Saturday and Saturday night, another round of widespread showers and thunderstorms is likely Sunday night into Monday that could produce heavy rainfall. - Hot and humid conditions are forecast to develop for the second half of next week with the potential for high temperatures in the mid 90s Wednesday through Friday. && .SHORT TERM /THROUGH TONIGHT/... Issued at 245 AM CDT Fri Jun 5 2026 Scattered showers and thunderstorms are forecast to continue across the area through the mid morning hours with skies clearing from northwest to southeast during the afternoon. This will allow heat and humidity to build across the area ahead of a cold front that will move into the area Saturday morning. This will allow heat and instability to build across the area during the afternoon. High temperatures today are forecast to rebound into the mid to upper 80s across the area with dewpoints in the upper 60s to around 70. HREF mean CAPE by early evening ranges from 2500 to 3500 J/KG across the CWA with deep layer shear of 30 to 35 knots across the area. This will be sufficient for severe thunderstorms late afternoon into the early evening, although there is uncertainty whether any scattered storms will develop in this time period. If storms were to develop, the main threats from this will be large hail and a secondary threat of damaging winds. The better forcing overspreads the area by mid to late evening with the best chances of showers and storm activity south of Interstate 80 overnight. This is the primary time for the Slight Risk (level 2 out of 5) for severe thunderstorms across the entire area. Scattered surges of wind are possible in the moist/precip-loading environment. In addition to the scattered severe threat, heavy rainfall will be possible with PWATs in the >1.25 inches with HREF probability match mean values of QPF near 2.00 inches in southeast Iowa. Totals this high would be favored if an area sees repeated rounds of showers and thunderstorms. Given the dry conditions across the area, rain may initially sit on the surface before slowly being absorbed into the ground. The Weather Prediction Center (WPC) also has a Slight Risk for heavy rainfall across the area for tonight. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Issued at 245 AM CDT Fri Jun 5 2026 Zonal flow aloft breaks down quickly on Saturday as 500 MB heights begin to build across the area at the surface and aloft. A stalled frontal boundary, partly modulated by outflow from tonight's storms, will remain near the Interstate 80 corridor on Saturday. It will be warm and humid on Saturday with high temperatures in the mid to upper 80s with dew points in the upper 60s to around 70 degrees. This will allow CAPE to build across the area south of Interstate 80 and isolated storms may develop Saturday afternoon or evening. Given the strength of the instability isolated severe thunderstorms and locally heavy rainfall are possible, but again confidence on development is not that high at this time. 500 MB heights will begin to rebound across Iowa Saturday night into Sunday ahead of a slightly negatively-tilted trough lifting from the Rio Grand Valley northeastward into the Upper Great Lakes Sunday through Monday. Have lowered high temperatures slightly for Sunday with the likelihood for cloud cover spreading into the area and southeasterly surface winds. High temperatures on Sunday are favored to be in the mid 80s. Lift begins to overspread the area during the late afternoon and overnight hours with showers and storms becoming more widespread Sunday night into Monday. Precipitable water values recharge across the area to around 2 inches so heavy rainfall is certainly possible. The timing for this wave may change as this is a closed low lifting into the area and those can be slower. Showers and storms linger into Monday and this has resulted in lowered high temperatures then as well. Tuesday onward, an Omega Block redevelops across the CONUS as 500 MB ridging builds back into the Central Plains while a closed low sits off of the East Coast and another in the Northern Rockies. High pressure is sprawling across the southern US with the Gulf open to pull moisture northward and into the area. This will allow dewpoints and temperatures to quickly climb Tuesday through Friday with high temperatures potentially into the mid 90s Wednesday through Thursday. No matter the specific values, it looks like the second half of next week will be hot and humid across the area. && .AVIATION /18Z TAFS THROUGH 18Z SATURDAY/... Issued at 1223 PM CDT Fri Jun 5 2026 A stationary boundary remains over our area, generally near I-80 from west to east. With moisture converging along this boundary, widespread rain showers and some thunder have persisted well into the late morning hours and could continue to be drizzle and rain showers early this afternoon north of Highway 34. Some isolated storms remain possible, but the next round of more notable thunderstorm activity should arrive late this evening as a wave moves along the front from west to east. These storms will be similar to last night, offering heavy rain and low cigs/visibilities and some threat for gusty winds. While the best 60-80% chance for storms will be along and south of I-80 tonight, storms are possible (30%) even in the northern areas like DBQ. Rain showers and lower cigs may linger into Saturday morning once again before gradually improving aviation develops, very chaotic, but also quite similar to today. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Cousins LONG TERM...Cousins AVIATION...Ervin