Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
424 FXUS63 KMKX 290101 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 801 PM CDT Tue May 28 2024 .KEY MESSAGES... - Light rain will continue into late tonight. - Quiet, pleasant weather prevails through mid to late week. - An active pattern returns this weekend through the beginning of next week, with periods of showers and thunderstorms expected. && .UPDATE... Issued 802 PM CDT Tue May 28 2024 Thunder has ended across the region, with just light rain persisting as cold cyclonic flow continues aloft. Rain will continue to percolate into the first part of the overnight, before the responsible mid level shortwave passes through the region. Some patchy fog is possible late tonight in low lying/sheltered locations, but there should be enough wind to mitigate a widespread fog risk. Boxell && .SHORT TERM... Issued 351 PM CDT Tue May 28 2024 Tonight through Wednesday night: Synopsis/Mesoanalysis: Convection is ongoing across southern Wisconsin this afternoon as a shortwave trough crosses the region. Activity has focused over two general areas through early afternoon. The first -- tied primarily to increasing DPVA ahead of the encroaching wave -- has remained relatively progressive, and will continue to advance eastward through early evening. A second, more narrow area of activity has persisted along & just west of the I-43 Corridor. Likely initiated by a combination of lift along the lake breeze & increasing forcing ahead of the approaching shortwave, said storms have remained quasi-stationary over the last several hours, with several stations in Ozaukee, Milwaukee, and Racine Counties reporting between 0.50 and 1.00" since noon. Anticipate that said clusters of storms will consolidate into one broad area of activity as the upper disturbance progresses overhead through early evening. Conditions will dry out tonight as high pressure builds in from the Northern Plains, with quiet weather prevailing through the remainder of the short term period. Rest Of This Afternoon/Early Evening: Storms will continue across southern Wisconsin, gradually tapering as surface temps cool & the upper disturbance currently overhead shifts east. Hydro is the greatest near-term concern with these storms, particularly within the batch of training activity along & west of Interstate 43. Flood Advisories have been issued for southern Sheboygan, northern Ozaukee, southern Milwaukee, and northeastern Racine Counties through early evening given continued training and multiple observations of 0.50-1.00" of rainfall since Noon. Despite the presence of favorable synoptic scale ascent & instability, an absence of any appreciable effective shear will prevent storms from organizing beyond their currently messy mode. This should preclude severe potential, though an isolated stronger storm with hail is possible given cold mid-level temperatures & attendant 6.5-7 degC/km lapse rates aloft. Gusty winds can`t be ruled out in any collapsing cores, particularly over southeastern zones, where the greatest amount of surface heating & steepened low level lapse rates were realized through early afternoon. SPC continues to carry a marginal (level 1/5) risk for severe weather across much of southern Wisconsin in light of this potential. Stay weather aware through early evening, and never drive through flooded roadways. Tonight: Conditions will quickly quiet down through mid-late evening as surface temps cool and the upper shortwave moves east of the region. Some patchy fog is possible near daybreak in the Wisconsin River Valley. Wednesday Night: Mostly clear skies and light winds will prevail, allowing for chilly overnight temps in the low 40s over central portions of the region. While not expected to be widespread, an isolated patch of frost can`t be ruled out in low-lying areas susceptible to cold air drainage. Frost advisories won`t be necessary. Quigley && .LONG TERM... Issued 351 PM CDT Tue May 28 2024 Thursday through Tuesday: Synopsis: High pressure will remain the predominant synoptic scale feature through the beginning of the period locally. Winds will gradually turn out of the south-southeast through late week as said area of high pressure pushes into the mid-Atlantic states. This will allow high temps to gradually climb through the end of the work week. An upper trough will eject into Saskatchewan on Thursday, progressing across Manitoba toward the western Hudson Bay from Friday into this weekend. The feature will linger over this general vicinity through Sunday, gradually deamplifying moving into the beginning of next week. The aforementioned evolution will allow quasi-zonal flow to prevail across the western Great Lakes through early next week & the conclusion of the long term period. Perturbations embedded within this upper pattern will combine with increasing moisture locally to support periods of showers and storms from Friday night through the beginning of next week. Friday Night Through Tuesday: Temperatures will continue to climb in the presence of continued southerly surface flow, with the afternoon update bringing high temps in the 80s back to the region from Sunday through Tuesday. Given the warm temps, increasing low level moisture, and periodically perturbed flow aloft, bouts of showers and storms appear likely. Precise details regarding timing & intensity of any storms remain murky given high amounts of spread apparent in available guidance. Will continue to monitor trends over the coming forecast cycles. Quigley && .AVIATION... Issued 802 PM CDT Tue May 28 2024 VFR is prevailing across the region this evening, though with pockets of MVFR and even IFR ceilings in a few spots. Light rain will persist into the overnight hours, before ending. Any lower ceilings will lift as well, with VFR expected through the day tomorrow. Winds will generally be from the north through the morning as high pressure builds into the area, before shifting to a more easterly or northeasterly direction in afternoon and evening as an enhanced lake breeze/backdoor cold front moves through. Boxell && .MARINE... Issued 351 PM CDT Tue May 28 2024 Scattered showers and thunderstorms are expected through the remainder of this afternoon and the first half of this evening, particularly over the southern two-thirds of the open waters. Widespread severe weather is unlikely, though a few storms could produce small hail and gusty winds. Breezy northerly winds will prevail on Wednesday, with gusts up to 20 knots possible during the afternoon hours. 1024 mb high pressure will linger across the Great Lakes through late week, resulting in light & variable winds Thursday through Friday. 992 mb low pressure will build into central Canada this weekend, allowing winds to turn generally out of the south. Periods of showers and thunderstorms will return from Friday night through the beginning of next week. Quigley && .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