Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
733 FXUS63 KMKX 230241 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 941 PM CDT Sun Sep 22 2024 .KEY MESSAGES... - Areas of fog are possible over northwestern counties later tonight. - Cooler/near normal temps are expected behind the cold front today through the start of the week with daily highs in the upper 60s and lower 70s. - High uncertainty in timing and placement for precipitation next weekend (15 to 30 percent chance). && .UPDATE... Issued 940 PM CDT Sun Sep 22 2024 Post-frontal, northerly flow continues to advect a cooler & drier air mass into the region this evening. Dew points have been a touch slow to fall---particularly over the eastern half of the area---though the push of dry/northerly flow should begin to win out nocturnally. Have adjusted the near-term dew point grids based on observational trends. Anticipate the coolest temps and driest dew points over the northwestern corner of the CWA through daybreak. The aforementioned overlap of temps and dew points could support areas of fog development across northwestern zones closer to daybreak Monday, with mentions being inserted into the weather grids in the latest update. Fog will quickly dissipate after sunrise tomorrow morning. Slow down, use low beam headlights, and allow for extra following distance if encountering reduced areas of visibility while traveling tomorrow morning. Quigley && .SHORT TERM... Issued 306 PM CDT Sun Sep 22 2024 Tonight through Monday night: A Beach Hazards Statement is in effect from this afternoon through Monday afternoon due to gusty winds producing 3 to 5 ft waves along Lake Michigan beaches and therefore producing a high swim risk. Based on observations, the cold frontal feature has almost completely pushed through southern Wisconsin (indicated by northwesterly wind gusts of 15 to 20 mph). Satellite indicates clearing skies and dry air intruding from the northwest, which will shut off drizzle production in the subsidence region of the frontal passage within the next few hours in southwestern Wisconsin. That being said, drizzle has been efficient so far this afternoon, and the subsidence region and its associated drizzle is therefore expected to propagate eastward into southeastern Wisconsin as steady rainfall ends in that region. Clouds will break up from west to east late this evening into tonight, and winds will diminish overnight as well. Expect overnight lows in the 40s, with the coolest temperatures in the lower 40s in the Wisconsin River Valley region. Dry conditions with northeasterly breezes expected Monday as high pressure nudges southward from the northern Plains. Partly cloudy skies will combat the cooler airmass, allowing for highs in the upper 60s to near 70 degrees. Overnight Monday, high pressure lifts back into Canada as a developing surface low in the Middle Mississippi Valley propagates northeastward. This low may produce rain and showers overnight into Tuesday, although confidence remains low (15 to 35 percent, with the highest chances in southeastern Wisconsin). Low temperatures in the upper 40s to lower 50s are expected, with higher lows in the upper 50s near Lake Michigan. MH && .LONG TERM... Issued 306 PM CDT Sun Sep 22 2024 Tuesday through Sunday: Low pressure exits to the east slowly on Tuesday as it interacts with a Canadian surface high, producing a few more chances for rain and showers through the day in southeastern Wisconsin (15 to 35 percent). After this low exits, a cooler airmass and high pressure will dominate through much of the week as a Rex blocking pattern sets up across the central U.S. Uncertainty increases going into the weekend, as global models indicate potential for a system of tropical origin nudges northward into the Great Lakes region. Timing, intensity, and precipitation amounts will be highly dependent on the evolution of this system in the Gulf of Mexico, and therefore my confidence for this timeframe is low. Kept NBM PoPs, which generally show a 15 to 30 percent chance from Friday through Sunday. That being said, the strength of the high pressure and blocking pattern will likely shift the timeframe of these chances farther into the future with additional model runs. MH && .AVIATION... Issued 940 PM CDT Sun Sep 22 2024 Predominantly VFR conditions prevail across southern Wisconsin this evening as drier air works into the region behind a departed cold front. MVFR categories continue to linger at KMKE and KENW, though improvements to VFR are anticipated over the next few hours. Have accounted for the expectations in recent TAF updates. Areas of fog are possible closer to the Wisconsin River during the predawn hours on Tuesday, with potential development coming closest to KMSN. Currently anticipate that FG will remain to the northwest of the terminal, which has precluded any mentions in the forecast. Will nevertheless monitor trends through sunrise and make amendments if necessary. Quigley && .MARINE... Issued 306 PM CDT Sun Sep 22 2024 Gusty northerly winds in the northern half of the open waters will spread southward through the remainder of the open waters this evening into tonight, with gusts up to 30 kt expected through the overnight hours in the southern two-thirds, including in the nearshore regions. An occasional gale force gust is possible in this region of the open waters. A Small Craft Advisory is in effect this afternoon through Monday afternoon for these elevated wind and wave conditions. Northerly winds will diminish Monday morning through Monday afternoon as high pressure builds into the northern Great Lakes region. As high pressure pushes eastward into Canada, expect winds to shift to easterly Monday night into Tuesday. Weak low pressure is then expected to develop in the Middle Mississippi Valley and lift into the eastern Great Lakes on Tuesday, leading to northeasterly winds. A few thunderstorms are possible across the southern half as this low develops. MH && .MKX WATCHES/WARNINGS/ADVISORIES... WI...Beach Hazards Statement...WIZ052-WIZ060-WIZ066 until 1 PM Monday. Beach Hazards Statement...WIZ071-WIZ072 until 4 PM Monday. LM...Small Craft Advisory...LMZ643-LMZ644 until 1 PM Monday. Small Craft Advisory...LMZ645-LMZ646 until 4 PM Monday. && $$ 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