Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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456 FXUS63 KDVN 041710 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1210 PM CDT Sat May 4 2024 .KEY MESSAGES... - Upper level pattern remains active, with periodic chances for showers and storms through next week. - The Storm Prediction Center has a Slight Risk (level 2 of 5) for severe thunderstorms across much of northwest Illinois and a Marginal Risk (level 1 of 5) to the west. The primary threats are strong wind gusts and hail. - A potent dynamic system arriving Monday night to Tuesday could bring a more significant severe threat. && .SHORT TERM /THROUGH SUNDAY/... Issued at 225 AM CDT Sat May 4 2024 A large MCS is poised to enter western Iowa early this morning, and is rapidly moving east/northeast. This has been severe in Nebraska, but will be quickly moving out of the marginally unstable air and should become predominantly stratiform rain in the next 4 hours prior to sunrise as it moves through Iowa and southern Minnesota. For us, skies will become high overcast before sunrise, and winds will continue to increase from the south/southeast. Some showers may near our northwest prior to 12Z, but this looks to hold off until then, and move into our northwestern 1/3 of the CWA before 10 AM. While in a dissipating stage, some thunder is possible, and will keep it`s mention in grids. During the late morning to early afternoon, coverage of rain in Iowa will wane, allowing some decent heating to occur in the east 1/2 of the CWA. the NBM supports highs in the upper 70s to around 80 today along and east of the Mississippi River, with dew point temperatures rising to the low 60s just ahead of the front. Modest CAPE of 500 to 1200 is forecast by most CAMs this afternoon in our east 1/2. The surface cold front should reinitiate convection near the Mississippi River. NBM pops came in today ~90% with the fropa, but with about 1/2 of the CAMs failing to convect today, I`m inclined to limit pops to 80% in the narrow fropa timing this afternoon. Anyhow, SPC is maintaining the Marginal Lvl 1 risk for mainly wind and hail. This is a low risk, but will be highest with the storms that form along the front this afternoon. By early evening, storms will have exited the area to the east, with rapid clearing and a chilly night in the upper 30s to mid 40s in store. Sunday, with cool air in place, a pleasant spring day is forecast, with some diurnal cumulus dotting the sky as well. Highs are forecast to reach the upper 60s to lower 70s. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Issued at 225 AM CDT Sat May 4 2024 A broad, energetic pattern is set to begin spreading WAA rain and thunder into the area as soon as Monday, with widespread showers and thunderstorms expected Monday night into Tuesday. This Monday night into Tuesday period continues to be shown as a large/synoptic, strongly forced system, and there`s been a consistent signal for a very strong jet streak within the Midwest. Those broad scale factors continue to give an indication that this may be a widespread severe weather producer, and our CWA may be included in that. We will begin messaging this chance today in the HWO. A warm and breezy pattern is in store on the east side of this broad potent trof next week. Highs in the 70s to lower 80s are expected through Wednesday. Following that, the upper trof is set to deepen, and place the warm air well south of the upper Midwest, resulting a cooler, cloudier forecast in the 60s to lower 70s to end the week. This could bring additional showers and possibly thunder to the region as well, given the cold air aloft and time of year over moist soil. The QPF in this period should not be overly heavy, given no connection to the Gulf of Mexico, but spotty rains over 0.50 appear possible in the frequent shower chances to end the week. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... Issued at 1200 PM CDT Sat May 4 2024 A cold front will move through eastern Iowa and northwest Illinois this afternoon and evening, leading to periods of MVFR ceilings. The morning round of showers and storms has quickly diminished, but redevelopment of scattered showers/storms is anticipated by mid afternoon. The coverage of storms will likely remain scattered and the higher chances for thunder are at MLI/BRL, which was mentioned in a TEMPO. A return to VFR is anticipated this evening/early tonight with breezy NW winds through 6 PM - 9 PM before subsiding. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Ervin LONG TERM...Ervin AVIATION...Uttech