Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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514 FXUS63 KDVN 110820 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 320 AM CDT Sat May 11 2024 .KEY MESSAGES... - Nice weather to start the weekend with dry conditions and temperatures in the 70s today! - Warmest day in the next week will be Sunday with highs in the 80s; isolated to scattered storms are possible late Sunday afternoon into Sunday night. - The pattern will remain active next week as zonal flow aloft guides a series of shortwaves through the Midwest. && .SHORT TERM /THROUGH SUNDAY NIGHT/... Issued at 318 AM CDT Sat May 11 2024 Today: Seasonably warm with plenty of sunshine and highs in the low/mid 70s. NW winds will increase late morning into the afternoon, gusting 20-30 mph. Sunday: Low pressure passing near Lake Superior will pull warm and more moist air northward into the local area with forecast highs into the low to mid 80s. With dewpoints only in the 50s, humidity will remain comfortable and instability will peak around 1000 J/kg (per HREF SBCAPE). Deep layer shear is also on the low side at 20-30 kts, which will limit storm organization. Most CAMs develop isolated convection during the late afternoon and evening, with coverage increasing into Sunday night (30-50%). A dry sub-cloud layer shown on forecast soundings Sunday afternoon and evening would be supportive of gusty winds with the strongest cells, potentially over 40 mph. && .LONG TERM /MONDAY THROUGH FRIDAY/... Issued at 318 AM CDT Sat May 11 2024 Monday: An upper low on the northern periphery of the subtropical jet is forecast to slowly track from the Southern Rockies to the Lower to Mid Mississippi Valley early in the week. This will keep the local area on the cooler and more stable side of the surface low. Rain is likely to spread in from SW to NE during the morning and afternoon. NBM chances for measurable rain range from near 50% in the far NW corner of the outlook area to ~90% south of I-80. The 24 hour probability for 0.50" or more of rain reaches 50-70% south of I-80 and drops down to 20% near Highway 20. The NBM may still be running too warm for max temps due to the likelihood for widespread clouds and rain; these may need to be lowered by several degrees in later updates. Tuesday - Friday: There remains uncertainty with how fast the rain moves out on Tuesday. The ECMWF lingers the rain through the morning across the south half of the outlook area, while the GFS/CMC shift it to the SE more quickly. Our current forecast is leaning towards the latter scenario. Then it looks like we will get a break from the rain later Tuesday through Wednesday before the next shortwave trough and associated cold front arrive by Wednesday night into Thursday. Late week temps are forecast to be slightly above normal in the low/mid 70s. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1241 AM CDT Sat May 11 2024 High pressure will lead to prevailing VFR through Saturday. Light WNW to NW winds overnight will increase and gust 20-25 kts during the day on Saturday. No precipitation is expected through the period. && .HYDROLOGY... Issued at 955 PM CDT Fri May 10 2024 The Flood Warning continues for the Wapsipinicon River near De Witt. The initial crest has come in considerably lower and below flood stage, so the river is now expected to go into Minor flooding on the evening of Monday, May 13th when the second crest due to routed flow occurs. Given how the initial crest was lower and attenuation of routed flow confidence is dropping a bit on the river reaching flood stage. The overall situation with the Cedar and Iowa Rivers is more uncertain. Flood watches remain in effect for Marengo on the Iowa river, and the Cedar River near Conesville. The Iowa River at Marengo is forecast to go into Minor flooding Sunday evening May 12, while the Cedar River near Conesville is forecast to go into Minor flooding early Tuesday morning, May 14. Rainfall over the next 72 hours and where it occurs will be the deciding factor as to whether or not the Cedar and Iowa Rivers will reach flood stage near Conesville and at Marengo respectively. If the rainfall is lighter than expected then river forecasts may be lowered. However, if rainfall is heavier than expected then river forecasts may be raised. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Uttech LONG TERM...Uttech AVIATION...Uttech HYDROLOGY...McClure