Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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772 FXUS63 KDVN 261935 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 235 PM CDT Sun May 26 2024 .KEY MESSAGES... - There is a potential for strong to severe storms Monday afternoon. - A change in the flow pattern aloft will bring a period of quiet weather to the area for part of the coming work week. - Several weak disturbances in the flow aloft will bring a risk of rain to the area again next weekend. && .SHORT TERM /THROUGH MONDAY/... Issued at 233 PM CDT Sun May 26 2024 Isolated showers or storms are possible through sunset as the atmosphere continue to recover from the morning rain. Mid-level lapse rates are fairly stable but steeper lapse rates are beginning to arrive in concert with the upper low and vort max. With peak heating (roughly 3-5 PM in the warm season), storms may still fire mid to late afternoon with areas east of the Mississippi favored. Overall coverage looks to be low (15 to 30 percent) with any convection dissipating quickly with sunset. The potential is there for a couple of strong storms to develop that would pose a risk of hail and locally gusty winds. After sunset dry conditions will be seen for the entire area. On Monday the next upper level disturbance will arrive around mid- day. This disturbance is expected to generate diurnal showers and storms for the afternoon and potentially into Monday evening. With lapse rates steepening through the day, the potential is there for some strong to severe storms during the afternoon. If severe storms develop the primary risk looks to be damaging winds with hail a secondary risk. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Issued at 233 PM CDT Sun May 26 2024 Monday night and Tuesday Assessment...medium confidence There may or may not be some lingering showers and storms until sunset Monday evening. Overall, much of the area will be dry Monday night. On Tuesday another upper level disturbance will move through in the flow aloft. Although the forcing is weak the relatively wet ground should provide enough moisture through evapotranspiration to induce diurnal showers and thunderstorms Tuesday afternoon. Overall coverage will be on the low side (20-30 percent) with areas along and north of I-80 being favored. Tuesday night through Thursday night Assessment...high confidence The model consensus has dry conditions across the area Tuesday night through Thursday as an upper level high builds into the Midwest. Temperatures will slowly trend to and then slightly above normal. Thursday night will be interesting. The deterministic runs and more ensemble members are indicating dry conditions. While the model consensus still does not show this, pops have been lowered into the 20-25 percent range and confined to areas west of the Mississippi. Friday through Sunday Assessment...medium confidence Given the overall trend with deterministic runs and the respective ensemble runs of the models, pops are slowly being lowered during the day Friday. If this trend continues over the next several days, the prospects of Friday morning being dry would increase considerably that may extend into Friday afternoon. Based on the trends of the deterministic runs and ensembles, Friday night into Saturday generally looks to be the most likely time to see another round of rain. While the overall areal coverage is only 30-40 percent the time frame of Friday night into Saturday looks to be the favored time for rain. Saturday night rain may linger into the evening hours before slowly dissipating. Interestingly, there is another weak upper level disturbance in the flow aloft arriving on Sunday. Although the forcing is weak, if sufficient moisture is available there would be a low risk (20-30 percent) for showers and a some thunderstorms. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1232 PM CDT Sun May 26 2024 Some isolated to possibly scattered SHRA/TSRA may occur through 02z/27 across eastern Iowa and northern Illinois. However the probability of a TAF site being impacted is 10 percent at best. Otherwise IFR/MVFR conditions will slowly improve to VFR through 03z/27 from southwest to northeast. After 03z/27 expect VFR conditions as high pressure builds into the Midwest. After 18z/27 and upper level disturbance is expected to generate isolated to scattered SHRA/TSRA. && .HYDROLOGY... Issued at 1232 PM CDT Sun May 26 2024 Swaths of 1-2 inches of rain occurred overnight and early this morning in the headwaters and portions of the channels of the Wapsipinicon, Cedar and Iowa River basins. This will prolong high water levels and minor to major flooding on these rivers from the main channels to the confluence of the Cedar and Iowa Rivers, and Iowa and Wapsipinicon Rivers with the Mississippi River. This routed water will also lead to further rises on the mainstem Mississippi River, with many locations nearing action stage through midweek from Dubuque (DBQI4) down through Muscatine (MUSI4) while minor flooding is expected in many locations from Keithsburg (KHBI4) to Gregory Landing (GGYM7). Please refer to the latest Flood Statements and Flood Warnings for more details. The forecast will have chances for sporadic rains over the next couple of days, but significant rainfall is not expected. Beyond, it looks to turn more active heading into the first week of June. The Climate Prediction Center has the area favored for near normal rainfall June 2-8. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...08 LONG TERM...08 AVIATION...08 HYDROLOGY...McClure