FXUS63 KDVN 150906 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 406 AM CDT Wed Apr 15 2026 .KEY MESSAGES... - Rounds of showers and storms are expected through tonight. Additional severe storms are possible, mainly this afternoon and evening. The entire area is in a Slight Risk (level 2/5) for severe weather. - Threat for flash flooding from the potential for repeated rounds of storms and high rainfall rates through this evening. Greatest concern is north of the Hwy 30 corridor where the ground is saturated from recent heavy rains of 1-3+ inches. Any additional heavy rain in these areas will increase the risk for flooding, and a Flood Watch has been issued through this evening. - SPC has expanded the Enhanced Risk (level 3/5) for severe weather to include much of the area Friday. Damaging winds and tornadoes appear to be the primary threats. - Turning much cooler/seasonable this weekend with the potential for frost/freeze conditions Saturday night and again Sunday night. && .SHORT TERM /THROUGH TONIGHT/... Issued at 351 AM CDT Wed Apr 15 2026 Showers and storms are widespread early this morning north of Hwy 34 aided by ascent from a weak mid level impulse and elevated warm, moist advection atop a cool pool with an outflow boundary near a Princeton, IL to Mount Pleasant, IA line continuing to advance southeastward. Some gusty winds and isolated hail cannot be ruled out across the south where a moderately unstable environment has largely been left undisturbed until now. In addition, a veered LLJ is leading to at least a temporary favorable setup for a period of training of convection and locally heavy rain immediately north of the outflow. Anticipate a gradual decrease in coverage by mid to late morning, with the waning nocturnal LLJ and passage of the shortwave. The break in activity may allow for some recovery or destabilization to occur ahead of a more vigorous shortwave trough and attendant surface low lifting through western Iowa this evening. The amount of recovery/destabilization is uncertain and thus some uncertainty exists with the magnitude/ coverage of severe storms later today through this evening. That being said, higher confidence exists on more widespread coverage of storms this afternoon into tonight due to the arrival of stronger dynamics/forcing aided by 50-70m height falls at 500 hPa and more robust mid level flow with 50-60+ kt winds 700-500 hPa. This should foster more widespread convection by later today and tonight with an attendant severe threat with all hazards in play. The lifting low should help lift the remnant outflow back northward as a pseudo-warm front by this evening. While overall low level shear is much weaker, there will be a tornado threat perhaps mostly focused along/near this boundary with any cells that can ingest the enhanced SRH. Right now this boundary placement looks to be roughly between Hwy 30 and Hwy 34 by this evening, and thus the higher 5% tornado probabilities in this area mainly on the Iowa side where shear is a bit higher being in closer proximity to the lifting surface low. The strong deep layer shear will provide good venting aloft and combined with a rather perpendicular vector to the initiating boundary will prove favorable for discrete supercells initially with all hazards in play. Then in time, we may see a more mixed mode with perhaps more muticell/linear evolution taking place tonight ahead of the advancing cold front, with largely a resulting wind and isolated tornado threat. Potential for repeated storms and periods of high rainfall rates of 1+ inch/hr will foster a threat for heavy rain and flooding. The greatest risk or most vulnerable area appears to be north of Hwy 30 where the ground is saturated from recent heavy rainfall of 1-3 inches, and as a result I have issued a Flood Watch through this evening. This activity should start to diminish by late evening and overnight with the passage of the cold front. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Issued at 351 AM CDT Wed Apr 15 2026 A short period of drier weather is expected by Thursday afternoon through Friday morning, as a bout of high pressure quickly traverses the region. As the high departs Friday afternoon, return flow/warm advection will commence and strengthen with a warm front lifting northward into the region. We will have to watch for any storm development in the afternoon along the lifting warm front. Currently though this potential is looking somewhat lower due to some capping and lack of synoptic scale ascent. The main corridor for severe storm development Friday PM looks to be to our west ahead of a cold front and deeper surface low attendant to a lifting shortwave. Very strong wind fields with parallel vector orientation to the cold front should support a fairly quick transition and upscale growth to a line of storms or QLCS, which should then sweep eastward across the area during the evening and early overnight with mainly an attendant damaging wind threat, and tornado threat with any embedded mesovorts. SPC has expanded the Enhanced Risk (level 3/5) to include much of the service area for Friday. The strong cold front will sweep through the area late Friday night/early Saturday. In the wake, scattered showers are possible Saturday PM in the cyclonic flow/cold advection. Otherwise, blustery and much cooler/seasonable conditions are on tap Saturday and Sunday. Temperatures look to dip down around or possibly below freezing in parts of the area both nights leading to the potential for frost (should winds decouple) and/or freeze conditions. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 110 AM CDT Wed Apr 15 2026 Predominantly VFR with MVFR/IFR bouts in storms through the period. A line of storms south of KCID and KDBQ will likely impact KMLI and KBRL over the next several hours (through 10z) with MVFR to IFR conditions (mainly visibility). This may be preceded by gusty NW winds to 30+ kt with additional gusts possible with the storms. Elsewhere, mainly showers will linger at times near KDBQ and KCID prior to daybreak. Timing of the precipitation beyond the next 6 hours remains quite challenging. Overall it looks like there will be a decrease in precipitation coverage between 12z-18z, then an uptick is anticipated after 20z through Wednesday evening as a surface low and cold front move through. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...Flood Watch through this evening for IAZ040>042-051>054. IL...Flood Watch through this evening for ILZ001-002-007. MO...None. && $$ SHORT TERM...05 LONG TERM...05 AVIATION...05