Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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270 FXUS63 KDVN 041850 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 150 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 for this afternoon and early evening, 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 145 PM CDT Sat May 4 2024 This Afternoon and Evening A cold front currently located from near Decorah, Iowa to Kirksville, MO will steadily progress eastward through the outlook area this afternoon and evening, serving as the focus for scattered storm development. Low-level moisture advection via southerly flow has pushed dewpoints into the low/mid 60s ahead of the front, and locations along and east of the Mississippi River have had periods of filtered sun with temps warming into the mid/upper 70s. Trends with latest CAMs has been for a little lower coverage of storms this afternoon and early evening, so have lowered rain chances a bit. The best chances (40-70%) for storms are expected in counties along/east of the Mississippi River between 3 - 6 PM. Overall the environmental setup (500-1500 J/kg MLCAPE and ~30 kts deep layer shear) looks supportive of a few strong to severe storms with the weaker shear as a limiting factor. The strongest cells that pop up could produce wind gusts of 50 to 60 mph and hail up to quarter size, with this likely to occur on an isolated basis. Tonight and Sunday A drier and much cooler post-frontal air mass ushers in tonight with forecast lows in the upper 30s NW to upper 40s east/southeast. Sunday will be very nice with highs in the upper 60s to low 70s and fairly light winds through the day. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Issued at 145 PM 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. SPC has a Day 4 Slight Risk for severe weather encompassing the entire outlook area. Latest CSU ML probabilities for severe weather also highlight the local forecast area, with the max values to our southeast over central to southern Illinois into Indiana. 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...Uttech LONG TERM...Ervin/Uttech AVIATION...Uttech