Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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412 FXUS63 KDVN 120012 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 712 PM CDT Sun Aug 11 2024 .KEY MESSAGES... - Active stretch of weather ahead of us, with near daily chances for precipitation somewhere in our area. Best chances for more widespread showers/storms will be midweek and beyond. - Temperatures trending near normal by midweek, with most in the low-mid 80s. && .SHORT TERM /THROUGH MONDAY NIGHT/... Issued at 131 PM CDT Sun Aug 11 2024 High pressure remains planted over the region through today, where it will slowly start to slide east this evening and through tonight, as a new wave emerges over the region. Currently, satellite data suggests this wave is over the Central Plains, with the attendant surface low developing. This will progress east tonight, with a push of moisture working it`s way into our south. Some guidance suggests the onset of precipitation quite early tonight, but given some dry air to work through, I wouldn`t be shocked if we don`t start to see measurable precipitation until after midnight. This is highlighted well in the HREF as well, bringing the precipitation in between 3-6am. The best moisture will be situated south of Interstate 80, where the best PoPs have been placed. Areas south of I-80 have the best chance to see upwards to a 0.25-0.50"+ rainfall, with those south of Highway 34 potentially seeing between 0.50-1.00". The increasing moisture and resultant cloud cover will allow temperatures to be more mild tonight, with much of the area near or above 60, with the exception of our northeast. Tomorrow, the wave is expected to move out, with LLVL easterly flow aloft helping to diminish the rain chances through the day, with dry air moving in. A brief period of high pressure fills in behind the low, bringing a break in precipitation before the next wave approaches the area. With the presence of clouds through much of the day and showers in our south, temperatures are not expected to increase much tomorrow. Much of the area should remain in the low-mid 70. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Issued at 131 PM CDT Sun Aug 11 2024 Upper ridge continues to build over the Central US Tuesday, slowly pushing east into Wednesday. Weak waves will continue to pass through the flow, which may bring low-end chances for precipitation. The best wave will start its approach to the region Wednesday/Thursday, bringing the better chances for widespread rainfall, which can be heavy. This timeframe has been highlighted by the WPC, bringing in the most precipitation for the week. Current timing seems to start Wednesday afternoon, with increasing coverage through the night and Thursday. The best moisture arrives on Thursday, which is resolved well amongst guidance, hinting at upwards to 2.00" PWATs or higher. Given our past heavy rainfall events this summer, I am not quite sure that we will go much higher than that 2.00" PWAT, as we have underperformed compared to guidance prior. In either case, PWATs between 1.50-2.00" are near or greater than the 90th percentile in climatology, indicating that we can expect heavy rain in any thunderstorm. While I don`t plan on discussing deterministic QPF values, the ECMWF ensemble suite seems to favor at least 0.50-1.00" of rain, with 50-90% favorability. While this is the wettest of the solutions, it has been quite consistent and increasing. As was mentioned in the previous discussion, there is a non-zero severe risk during this timeframe as well. Although, it is a ways out and much can change, especially with the timing and track of the system, which are important ingredients in the recipe. So, stay tuned, but be prepared for a rainy mid-late week! Temperatures will be near normal through the week, with some trending slightly above normal. Temperatures heading into the weekend may be up for discussion though, as temperatures may not be as warm as advertised. The GFS and EURO both cut the upper low off over the Great Lakes region, with our area under the western flank of the system. Thus, we would fall under largely northerly to northwesterly flow Friday and through the weekend. This would put us under cold advection and keep the chance for possible wrap-around precipitation into the weekend. Thus, the weekend might trend a bit cooler than normal and remain gloomy. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 655 PM CDT Sun Aug 11 2024 VFR will continue into tonight with increasing high and mid clouds. Showers are possible by early Monday morning mostly at BRL, which could last into the afternoon. The precipitation will be accompanied by MVFR ceilings between 1500-3000ft AGL. Further to the north at CID and MLI, anticipate ceilings to lower to 3000-5000 ft AGL later Monday AM into the afternoon. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Gunkel LONG TERM...Gunkel AVIATION...Uttech