Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
650 FXUS63 KMKX 070245 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 945 PM CDT Sat Jul 6 2024 .KEY MESSAGES... - Round of showers and some thunderstorms well after midnight and into Sunday morning. - Continued near daily chances (30-50%) for showers and thunderstorms through the middle of next week. && .UPDATE... Issued 912 PM CDT Sat Jul 6 2024 Current forecast remains largely on track as of this evening. Areas of convection are ongoing to our west in the Plains. Anticipate that some of this activity -- namely the storms currently along the Missouri-Iowa border -- will make it into southern Wisconsin near and after sunrise Sunday. Storms will be well into their decaying stages upon arrival, with no severe weather hazards expected. The forecast picture becomes murkier moving into Sunday afternoon, when additional periods of scattered showers and storms are expected. It remains difficult to offer specifics regarding precise coverage and timing, with many details being dependent on the evolution of storms currently to our west. Based on the arriving 00Z high-res runs, a range of possible scenarios remain in play, with some forecast solutions depicting air mass/garden-variety thunderstorms, and a pair of others hinting at more organized clustering of storms along one or more MCV`s tied to tonight`s storms in the Plains. Observational and model guidance trends will continue to be monitored through the overnight hours, with necessary amendments being introduced to the Sunday PM forecast as conditions warrant. Severe potential is low in tomorrow afternoon`s storms, though an isolated stronger storm with small hail and gusty winds can`t be ruled out, particularly in the scenario that more organized development along MCV`s is realized. Quigley && .SHORT TERM... Issued 250 PM CDT Sat Jul 6 2024 Tonight through Sunday night: There remains a small chance for a shower to occur late this afternoon, though most of this activity has been south of the Illinois border. Best chances would be along the lake breeze boundary, though most of the area should remain dry. There should be an area of showers and some thunderstorms that move east northeast into the area well after midnight and into Sunday morning. The low level jet veering over the area should help drive this activity, along with passing differential CVA. This activity may gradually weaken as it shifts through the area. More chances for showers and storms are forecast for Sunday afternoon and night, as continued differential CVA occurs with some warm and moist advection in the low levels. There is more mean layer CAPE Sunday afternoon and night, though tall and skinny with deep layer bulk shear perhaps 25 to 30 knots. Thus, not expecting severe weather. May see locally heavy rainfall if storms move over the same areas. Warm and humid conditions should linger during this period. A southeast lake breeze is expected Sunday afternoon near Lake Michigan. Wood && .LONG TERM... Issued 250 PM CDT Sat Jul 6 2024 Monday through Saturday: Continued chances for showers and storms are forecast at times for Monday into Wednesday, as the main 850 to 500 mb trough axis slowly pushes eastward through the region. Ensembles generally support this trend. There will be perhaps more diurnally- driven showers and storms during this period, with tall and skinny mean layer CAPE building during peak heating with little capping and bulk shear of 25 knots or so. Winds will shift to the west Monday night into Tuesday, as a weak cold front moves through. Warm and humid conditions will remain during this time per ensemble trends. High pressure may develop over or to the northeast of the region for later in the week, though a slow-moving 500 mb shortwave trough may linger over the area. This feature is supported by the ensemble Cluster Analysis of 500 mb heights. Periodic chances for showers and storms will continue for this period, with warm and humid conditions remaining. Wood && .AVIATION... Issued 912 PM CDT Sat Jul 6 2024 VFR conditions continue through the majority of the overnight hours at the southern Wisconsin aerodromes. Clouds will gradually thicken as SHRA/TSRA currently ongoing over the Plains approaches from the west. Anticipate that the remnants of some of the aforementioned precip makes it into the region near and after sunrise Sunday. Confidence in TSRA is low, given that activity will be well into its decaying stages as it arrives. Have thus carried PROB30 groups mentioning TSRA with MVFR cigs at the I-39 fields, with omissions further east. Will continue to monitor trends through the overnight hours and make amendments if necessary. Expect a break in activity during the afternoon hours, with additional development possible during the evening hours. Will continue to monitor guidance trends and refine timing of this second round over the coming forecast cycles. Quigley && .MARINE... Issued 250 PM CDT Sat Jul 6 2024 Light south winds are expected tonight, as weak high pressure around 30.0 inches passes by to the southeast. South winds should then persist across the lake into Monday, then shift southwest to west Monday night into Tuesday. Winds should then shift north to northeast by Wednesday. Several rounds of showers and thunderstorms are possible during this time. Wood && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...None. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSMilwaukee www.twitter.com/NWSMilwaukee www.youtube.com/NWSMilwaukee