Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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612 FXUS63 KDVN 220004 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 704 PM CDT Sat Sep 21 2024 .KEY MESSAGES... - Marginal Risk for severe storms late this afternoon into tonight for the far NW CWA. - Damp and much cooler for Sunday and Monday with highs in the mid 60s to lower 70s, which is slightly below normal. - Dry conditions are expected to prevail Tuesday through Thursday with high temperatures in the low to mid 70s. && .SHORT TERM /THROUGH TONIGHT/... Issued at 200 PM CDT Sat Sep 21 2024 An area of scattered showers and isolated storms has worked from west to east through mostly the southern half of the outlook area this morning into the early afternoon, leading to localized downpours and gusty winds of 25-35 mph. This activity was likely enhanced by a gravity wave propagating through the region as shown on GOES visible satellite imagery and coincided with the earlier uptick in areal coverage. The rain and widespread cloud cover, especially south of I-80, has lowered temperatures to the low/mid 70s across the south and southwest forecast area, while locations to the north and east are in the upper 80s to near 90 degrees. For the remainder of this afternoon into this evening, redevelopment of isolated showers and storms are possible but with low coverage anticipated and much of the area likely to stay dry. The prospects for severe weather remain low due to waning instability heading into early tonight and only modest deep layer shear around 25-30 kts per the 12Z HREF; SPC has maintained the Marginal Risk (level 1 of 5) across the NW portion of the forecast area. A better chance for scattered showers/storms comes in late tonight as convection initiating this afternoon over central Iowa, and extending down into Kansas, slowly spreads ENE in tandem with a surface cold front sagging in from the NW. Additional rounds of rain with embedded thunder are expected overnight into Sunday morning (highest chances southeast of Dubuque to Iowa City ~80%). Rain amounts will vary quite a bit across the region due to the spotty nature of the rain, but on average anticipate 0.25 - 0.75 of an inch. && .LONG TERM /SUNDAY THROUGH SATURDAY/... Issued at 200 PM CDT Sat Sep 21 2024 Sunday - Monday: An upper wave will move through the area, with showers and isolated storms likely to linger through Sunday AM before diminishing during the afternoon. An increasing northeast wind and cold advection will keep temperatures steady in the 60s to low 70s both Sunday and Monday. The upper trough will influence our area into Tuesday, with some shower chances continuing in the southern CWA. As dry air arrives, the overnight lows will drop to the upper 40s to lower 50s, making for chilly mornings more typical of early fall. Slow moderation is forecast by late week, along with a slight chance for rainfall. Late week forecast highs are in the 70s, and lows in the 50s. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 701 PM CDT Sat Sep 21 2024 A more widespread area of rain and embedded thunder is expected later tonight into Sunday morning, which will likely be accompanied by MVFR/IFR ceilings and MVFR visibilities. The showers should gradually end in the afternoon. Confidence remains low on the exact timing and location of any embedded storms through the period. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Uttech LONG TERM...Ervin AVIATION...Haase