Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
Issued by NWS Quad Cities, IA IL
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258 FXUS63 KDVN 051704 AFDDVN Area Forecast Discussion National Weather Service Quad Cities IA IL 1204 PM CDT Sun May 5 2024 .KEY MESSAGES... - Upper level pattern remains active, with periodic chances for showers and storms through next week. - A potent dynamic system arriving Monday night to Tuesday will bring a more significant severe threat in the region, and possibly our CWA. && .SHORT TERM /THROUGH MONDAY/... Issued at 143 AM CDT Sun May 5 2024 Despite the cool start that looks in store this morning, today will be a nearly ideal late spring day, with ample sunshine, dry air, light winds, and highs in the upper 60s to lower 70s. If you`re able, get out an enjoy this fabulous weather today! Quiet weather looks to last through tonight and Monday morning, as surface high pressure keeps the moisture shunted well south of Iowa. Lows tonight will fall to the 40s again, with lower to mid 70s expected for highs Monday. Monday will see increasing humidity through the day, but deep moisture should not spread into the area until Monday night. This means most all of Monday now appears dry, with the focus for both rain and severe weather holding closer to the Plains and Missouri Valley region. Monday night, in a mature to decaying phase, this forcing and deep moisture will arrived in our area. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Issued at 143 AM CDT Sun May 5 2024 Models are now showing a more consistent signal that Monday night will be the best chance for widespread rain and thunderstorms in the coming days. As stated in the short term, a mature to decaying phase of MCS/QLCS should arrive from the west during the late evening. This convection will most affect our entire area between Midnight and 10 AM Monday night/Tuesday AM. PWAT values over 1.25 are forecast with this strong WAA forcing. Thus, rainfall on the order of 0.75 to 1.25 is likely where storms maintain a mature convective signature, while lesser totals are expected in the east 1/3 where dissipating convection is more likely very late Monday night/Tue AM. There will be deep layer shear around 40-50kts overnight, but little boundary layer instability to work with. Some organized wind threat seems possible in mature QLCS in our western areas, but this will probably lose it`s punch as it heads east encountering more stable air at lower levels. SPC has our southwest in Marginal (lvl 1 of 5). Tuesday is questionable with placement of the surface boundaries. Nearly all deterministic models suggest that the surface boundary for active storms will be south of the area Tuesday, with additional placement of storms closer to the low center located well north of the area. A SPC forecast of Marginal (lvl 1) will be in place over our Illinois counties. Beyond this early week busyness, all guidance suggests a broad deep upper trof will build into the Great Lakes through the end of the week. This will bring cooler weather, along with frequent, somewhat diurnally driven shower and thunderstorm chances through the end of the week. Highs in the 60s are forecast, but pending cloud cover, we could be limited as low as the mid 50s in this pattern. Rainfall, while not heavy, could see daily totals of ~0.25 inch in scattered showers/storms. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 1200 PM CDT Sun May 5 2024 High pressure will remain in control through the period with prevailing VFR. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...None. IL...None. MO...None. && $$ SHORT TERM...Ervin LONG TERM...Ervin AVIATION...Uttech