NWS Milwaukee Forecast Discussion
483 FXUS63 KMKX 170913 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 413 AM CDT Fri May 17 2024 .KEY MESSAGES... - Areas of dense fog are possible early this morning, especially east of Madison. - Marine dense fog developed on Lake Michigan, and may linger through tonight. - Summer-like temperatures and dry Today-Sun. - A wet and unsettled period for Mon-Tue. && .SHORT TERM... Issued 413 AM CDT Fri May 17 2024 Today through Saturday: High pressure settled in overnight. Southwest winds descending toward the lakeshore in far southeast WI helped temps remain elevated overnight when compared to other areas of south central and southeast WI. With dewpoints in the lower to mid 50s and temps dropping to those values, along with clear skies and calm winds, patchy fog is developing. Most susceptible areas for dense fog are river valleys, marshy areas, and east central WI. The Fox River Valley is fogged in and the fog is expanding southward into Sheboygan and Fond du Lac Counties between I-45 and I-43. We will continue to monitor satellite and obs trends and issue a Dense Fog Advisory for additional counties as necessary. With an early sunrise, the dense fog threat would only last until around 8 AM. High pressure, plenty of sunshine, and light winds will allow for a lake breeze to develop early today, but the light flow should prevent it from making it too far inland until dusk. The dry air in place should also allow for dewpoints to drop toward the lower end of guidance, in the upper 40s for inland areas. This, and also subtle warm air advection tonight, will make it difficult for fog development tonight. Lakeshore areas would still be a little susceptible. Saturday will be our warmest day of the weekend with highs in the lower-mid 80s inland. A modest southerly breeze for inland areas will still allow that lake breeze to develop, but will not allow for progress inland. Lakeshore highs will be in the 70s. Cronce && .LONG TERM... Issued 413 AM CDT Fri May 17 2024 Saturday night through Thursday: A weak trough will cross southern WI Saturday night. Showers and a few rumbles of thunder are possible along that trough in western WI Sat afternoon, but precip chances should dwindle with loss of daytime heating. In addition, the main source of the forcing is from a closed upper low over Manitoba. Sunday looks dry and warm, but not quite as warm as Saturday. The upper level pattern will transition into a western trough- eastern ridge early next week, and then become more zonal as the week goes on. This puts southern WI in the unsettled, active weather zone. Showers and thunderstorms are possible Monday morning as one shortwave moves through, and timing/daytime heating will drive how widespread those storms become. The next shortwave will arrive Tuesday and the associated surface low is expected to be stronger, crossing WI Tuesday afternoon/evening. There would be a greater potential for stronger storms with this Tuesday system. The wave train should continue through the latter half of the week and bring additional shower and thunderstorm chances to southern WI. Temps for much of the week should be in the lower 70s inland and mid/upper 60s lake counties. Cronce && .AVIATION... Issued 413 AM CDT Fri May 17 2024 Patchy dense fog developed early this morning and is impacting a couple of airports at times. Sheboygan, West Bend, Waukesha and Watertown are all in favorable spots for that patchy dense fog. Expect fog to dissipate by 14Z/9AM. VFR conditions are expected for the rest of the TAF period thanks to high pressure and dry air in place. Winds along the lake will have directional changes due to a lake/land breeze. Cronce && .MARINE... Issued 413 AM CDT Fri May 17 2024 Satellite trends, ship observations, and shoreline obs all indicate areas of dense fog over most of Lake Michigan early this morning. A Marine Dense Fog Advisory is in effect. The conditions will remain favorable through tonight due to high pressure and warmer air flowing over the cooler lake water, but there is uncertainty in the timing/area of how long the dense fog will stick around. No wind/gale concerns through Monday. Cronce && .MKX WATCHES/WARNINGS/ADVISORIES... WI...Dense Fog Advisory...WIZ051-WIZ052 until 8 AM. LM...Dense Fog Advisory...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563- LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779- LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 until 4 AM Saturday. Dense Fog Advisory...LMZ643 until 4 PM Friday. && $$ 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