Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
120 FXUS63 KMKX 150217 AAA AFDMKX Area Forecast Discussion...UPDATED National Weather Service Milwaukee/Sullivan WI 917 PM CDT Mon Jul 14 2025 .KEY MESSAGES... - Increasingly very warm and humid conditions into Wed. Maximum heat index values reaching the lower 90s for Tue-Wed. - Thunderstorms are looking likely for Wed afternoon and evening due to a wave of low pressure and cold front moving through srn WI. Severe thunderstorms and heavy rainfall are possible. - Looking drier and cooler for Friday if the cold front pushes and stalls further south in IL, but unsettle weather with 20-40% shower/storm chances return for the weekend. && .UPDATE... Issued 917 PM CDT Mon Jul 14 2025 Temperatures are hanging on in the 70s this evening, and dewpoints are in the mid to upper 60s. Once winds diminish, some patchy fog is possible overnight, especially in river valleys, marshes and other low- lying areas. Cronce && .SHORT TERM... Issued 245 PM CDT Mon Jul 14 2025 Tonight through Tuesday night: High pressure over the nrn Ohio Valley will slowly move to the lower Great Lakes and Mid Atlantic States into Tue, while a sfc trough and cold front over the nrn Great Plains slowly advances east and south toward the Upper MS River Valley and wrn Great Lakes. Lgt swly winds and warm, moist advection will boost temps and dewpoints during this period. High temps in the mid to upper 80s for Tue-Wed with maximum heat index values in the lower 90s. Lake breezes will occur each day but not penetrate too far inland. Nights will becoming milder and muggy especially Tue nt. Gehring && .LONG TERM... Issued 245 PM CDT Mon Jul 14 2025 Wednesday through Monday: A shortwave trough will approach from the west for Wed afternoon and evening with a wave of low pressure at the surface. Mid level lapse rates will be rather poor at 5.5-6.0 C/KM, but middle 80s temps and dewpoints around 70F should still yield MLCAPE of 1500 J/KG or more. Deep layer shear of 30-40 kts is forecast while low level shear will be weak. A strong to severe MCS will certainly be possible with damaging winds as the main hazard. There are differences among the models on the passage of the low and cold front so a slower version could result in a few lingering showers or isolated storms on Thu. Otherwise nly winds and cold advection will prevail on Thu with high pressure building into WI and the wrn Great Lakes for late on Thu and into Fri. Pleasant high temps in the 70s will return for this period. Slight upper ridging will then set up over the nrn USA Rockies for the weekend into early next week yielding wnwly flow aloft from the nrn Great Plains into the Great Lakes. At the sfc a stationary front will mainly set up along the Mid MO River Valley but it could shift farther north and east at times. A few MCS`s could occur along and just north of the front during this period which includes 30-40 percent chances each day or night for srn WI. Gehring && .AVIATION... Issued 917 PM CDT Mon Jul 14 2025 Areas of fog will be possible in the WI River Valley early Tue morning along the Sauk and Iowa County border. Patchy fog is possible in other low lying areas, but should be less widespread than last night. Sct030-040 fair wx cumulus is expected again on Tue. VFR conditions tonight through Tue night. Cronce && .MARINE... Issued 245 PM CDT Mon Jul 14 2025 Light to modest southerly winds will continue tonight into Tuesday night as high pressure over the northern Ohio Valley slides east to the Mid Atlantic States. A wave of low pressure around 29.8 inches will then move east across central or southern Wisconsin Wednesday afternoon or evening and cross Lake Michigan into lower Michigan Wednesday night. Numerous showers and storms will likely occur with the passage of the low and its cold front. Modest northerly winds will take hold after the passage of the low and cold front Wednesday night and continue into Thursday and possibly Friday. Gehring && .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