Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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636 FXUS63 KDVN 150845 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 345 AM CDT Sat Jun 15 2024 .KEY MESSAGES... - A quiet start to the weekend expected with mostly dry conditions through this afternoon. - Scattered showers and storms are possible tonight into Sunday morning, favored across the northwest portion of the forecast area. - Hot weather is expected Sunday through Tuesday with peak heat indices between 95 to near 100 degrees. Forecast temperatures drop by a few degrees for the middle to end of the week. && .SHORT TERM /THROUGH SUNDAY/... Issued at 315 AM CDT Sat Jun 15 2024 Today and Tonight GOES WV imagery showed a shortwave trough over eastern Colorado and a large MCS across portions of eastern Nebraska into north- central Kansas. As of early this morning, SPC Mesoanalysis had the MUCAPE gradient draped across eastern NE into northwest MO with no instability locally where dewpoints are in the 50s to upper 40s. CAMs are generally in good agreement on the Central Plains convective line to weaken as it approaches central to eastern Iowa. There are low chances for showers and isolated storms through the day mainly across the west and northwest counties, but forecast soundings are showing a dry sub-cloud layer. For this reason, much of the area is expected to stay dry through the afternoon/evening. Temperatures will range from the low 80s north to mid/upper 80s central and south, with comfortable humidity expected. As the mid-level shortwave glances the area late tonight, a period of scattered showers and storms is possible, especially across the northern portion of the forecast area. NBM rain chances range from near 20% along I-80 to 40-60% north of Highway 30. The HREF has MUCAPE increasing to near 1000-1500 J/kg with 30+ kts of deep layer shear, which could support a few strong storms with gusty winds the primary threat. Latest SPC outlook has a Marginal Risk for severe storms along and west of a Manchester, IA to Cedar Rapids to Memphis, MO line. Sunday Scattered showers and storms may linger north of I-80 during the morning hours before shifting east and dissipating. Otherwise, hot and humid conditions are expected with highs in the low to mid 90s and peak heat indices between 95 to near 100 degrees, highest south of I-80. Subsidence behind the departing shortwave should result in mainly dry conditions across the outlook area for the afternoon. A surface low tracking near Lake Superior will lead to breezy SW winds locally with gusts around 30 mph, providing some relief from the hot conditions. The resultant boundary layer mixing should hold dewpoints in the 60s and prevent much of the area from reaching Heat Advisory criteria, aside from on an isolated/brief basis. EC and GFS ensemble mean 850mb temps near 21 C are in the 95-97th percentile and have a return interval of 1 or more days per year, suggesting this is not an extremely unusual event. Fairly confident in highs topping out in the low to mid 90s for most areas; much lower confidence on locations reaching the upper 90s as shown by the NBM 50th - 75th percentiles. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Issued at 315 AM CDT Sat Jun 15 2024 Monday - Tuesday: Hot weather continues early in the week with forecast highs in the low to mid 90s (isolated upper 90s possible on Monday). Dewpoints will be the main player in whether locations hit Heat Advisory criteria (100 F). The NBM has been consistent with afternoon dewpoints in the mid/upper 60s, yielding peak heat indices on Monday between 95 to the lower 100s, and a little lower on Tuesday. An increasing surface pressure gradient between low pressure over the central and northern Plains and high pressure along the East Coast will lead to breezy southerly winds both Monday and Tuesday afternoon with gusts of 30+ mph, hopefully providing a little relief from the heat! Wednesday - Friday: The core of the upper-level heat dome is forecast to set up over the Eastern U.S. through the middle to end of the week, placing eastern Iowa and northwest Illinois on the western fringe. This may allow a surface boundary to drop in from the NW leading to occasional chances for showers and thunderstorms. With the increased chance for occasional rain and slightly cooler 850mb temps, forecast highs are several degrees cooler for the mid/late week period, yet remain in the mid 80s to lower 90s. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1244 AM CDT Sat Jun 15 2024 VFR to prevail through the period with light winds overnight, increasing out of the SSE on Saturday to 10-20 kts. There is a slight chance for isolated showers and storms mainly near CID and DBQ through the day on Saturday into Saturday night. However, confidence is too low on direct impacts at the terminals to mention thunder in the TAFs with this update. && .CLIMATE... Issued at 315 AM CDT Sat Jun 15 2024 Record High Temperatures: June 16: KMLI: 98/1918 June 17: KBRL: 98/1944 KMLI: 98/1897 Record Warm Minimum Temperatures: June 17: KDBQ: 74/1921 KMLI: 78/2018 June 18: KDBQ: 74/1921 KMLI: 77/2018 June 19: KDBQ: 76/1931 KMLI: 78/1953 && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Uttech LONG TERM...Uttech AVIATION...Uttech CLIMATE...Uttech/Schultz