Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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921 FXUS63 KDVN 230329 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1029 PM CDT Wed May 22 2024 .KEY MESSAGES... - Dry conditions for most today, with seasonable temperatures and comfortable humidity. - Active weather returns by Friday and again early next week with increasing shower and thunderstorm chances. There is a Marginal Risk (level 1 of 5) for severe weather on Friday. - The Cedar, Iowa, Skunk, and the Wapsi rivers are expected to rise with some sites going into flood in the next 3-4 days due to the recent 2-5 inch rainfall upstream. && .SHORT TERM /THROUGH THURSDAY/... Issued at 1205 PM CDT Wed May 22 2024 A beautiful early afternoon was unfolding across all of eastern Iowa, northwest Illinois and far northeast Missouri; a nice welcome after yesterday`s active weather. Skies featured mostly sunny skies with temperatures as of noon ranging from the mid 60s to near 70. It was breezy as well with west to northwest winds gusting around 20-30 MPH. 15z surface analysis showed a strong surface low just north of the arrowhead of Minnesota, with high pressure in place across the central Plains. The pressure gradient between the low and high was rather tight and, along with deep boundary layer mixing, was responsible for our gusty winds early this afternoon. Over the next 24 hours, our weather will be influenced by the the surface high as it slowly moves across the Plains into the mid- Mississippi River Valley. Gusty winds will subside late this afternoon and evening, becoming light & variable tonight into much of Thursday. Skies will feature only a few clouds, allowing for more of a diurnal swing to our temperatures compared to previous days. Look for lows tonight in the low to mid 50s (some upper 40s possible in valleys and low-lying areas), with highs Thursday recovering into the upper 70s to lower 80s ahead of strengthening ridging aloft. Will make note of a low chance of a shower or storm along and north of the Hwy 30 corridor this afternoon with a lobe of CVA moving through the area. However, this is low confidence given a lack of moisture in place across the area. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... Issued at 159 PM CDT Wed May 22 2024 Thursday night through Friday night... Our next chance of showers and thunderstorms arrives early Friday into the evening as a cold front moves across the Midwest. This will be in tandem with a negatively tilted shortwave and increasing diffluence aloft, increasing overall lift. Deep layer shear will be high in the 35-50 kt range with CAPE climbing into the 1500-2500 J/kg range, increasing potential for organized convection. Storms will also be capable of producing heavy rain as PWATs climb into the 1.25-1.50" range. Unfortunately, guidance is not in agreement of timing of the front this far out, and confidence on pinpointing where storms will fire is low. This is why there is a rather broad Level 1 (marginal) risk of severe thunderstorms for this period, which at time includes all of the DVN CWA. Saturday... High pressure will provide a dry start to the holiday weekend. Look for near normal highs in the low to mid 70s, and lows Saturday morning in the upper 40s to mid 50s. Saturday Night Through Memorial Day... Active weather returns as we head into Memorial Day with several shortwaves on track to move across the area. Ensembles including the NBM paint higher chances (50-70%) Saturday night with good agreement amongst deterministic guidance on more widespread showers and storms. Exact details on storm hazards at this time are low, though heavy rain is possible with a robust Gulf connection and PWATs climbing above 1.50" across portions of the area. Chances lower head into early next week but remain persistent through Tuesday (30-50%). Expect more details in the coming days. With the potential for precipitation, temperatures look to hold around or just below normal for Memorial Day. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 556 PM CDT Wed May 22 2024 VFR will prevail through the next 24 hours. Light winds are expected overnight before increasing out of the south on Thursday to 10 - 20 kts. Dry conditions will continue through the period. && .HYDROLOGY... Issued at 1030 PM CDT Wed May 22 2024 Watch/Warnings: Issued a Flood Watch for Cedar River at Cedar Rapids for potential to reach into the minor flood category in about 36 to 48 hours. Canceled the flood warning for the English River at Kalona. It crested near 14.2 feet earlier this afternoon and fell below flood stage during the late afternoon. It will continue to fall. Most of the river forecasts are starting to be based on routed flow. Some attenuation is still possible as the crest wave makes its way through the river systems over the next two to seven days. Because of this, confidence in some forecasts, especially those forecast to reach flood stage or a respective flood stage category beyond day 4, remain lower. Continued the watches for the Wapsi at DeWitt and the Cedar at Conesville which have over 2 days before reaching flood stage. Warnings continue at Anamosa, Marengo, and Sigourney with no category changes. Overall, this evenings crest forecasts have come in slightly slower and at or lower than prior forecast levels. Fore example, the Skunk River at Sigourney is now a half foot lower with a forecast crest a half foot over the Major stage. Forecast adjustments and possible additional watches/warnings will be made Thursday morning. Stay tuned. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Speck LONG TERM...Speck AVIATION...Uttech HYDROLOGY...14