Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
360 FXUS63 KMKX 061646 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 1146 AM CDT Mon Oct 6 2025 .KEY MESSAGES... - Scattered showers and storms with a cold frontal passage this afternoon becoming more widespread tonight with post frontal rain. - Dry and cooler with a return to seasonal temperatures Tuesday through Thursday. && .UPDATE... Issued 1146 AM CDT Mon Oct 6 2025 Cumulus clouds are developing along a cold front that stretches from se Sheboygan County to srn Green County, with stratus clouds and isold showers north of the front. Surface based convection is still looking possible over far se WI by 20-21Z when MLCAPE rises above 500 J/KG and CIN is reduced. A consensus of CAMs gives 50-60 percent chances over said region. Farther to the north and west post frontal showers and isold storms (30-50%) are forecast through sunset. Afterward, a 700 mb shortwave trough will approach from srn MN and nrn IA with 850 mb flow backing ahead of the trough. Well organized and fairly strong 850 mb frontogenesis will develop with 60-80% chances for showers tnt for much of srn WI. There remains very marginal elevated CAPE in the post frontal airmass so will still mention thunder. Gehring && .SHORT TERM... Issued 357 AM CDT Mon Oct 6 2025 Today through Tuesday: Slow moving cold front is beginning to push into the northwestern portion of the CWA early this morning. However, the shower activity along and ahead of it is weaken as there is limited upper-level support to maintain it at this time. Thus looking at scattered light showers for areas along and northwest of HWY-151 through day break. Additionally given this weakening trend in the morning shower activity, the lull in showers is looking increasingly more likely through the morning hours and current PoPs may be a bit too aggressive. This also would mean central portions of the CWA may miss out on much of the rainfall. However, the lack of morning activity would allow for the environment to recover quicker and build up more instability (500-750 J/KG of SBCAPE) this afternoon, thus supporting better thunderstorm potential across south eastern WI. Still not expecting any stronger storms given how displaced the line would be from the favorable upper-level dynamics, but still cannot rule out a very localized potential given the strong low- level/surface frontogenesis along with meager 0-3 km shear values around 30 kt. Again this potential is and remains very low, but if a stronger storm did happen to develop, gusty winds are likely the main concern given steeper low-level lapse rates along with low- level shear vectors remain fairly parallel with the frontal boundary. However, cannot rule out the non-zero chance (given a few similarities to the Oct event we saw a few years ago) to see a weak spin up within this broken line of showers/storms, especially if there is a bulge within the line if stronger/deeper storms develop and if the 0-3 kt shear vectors turn more perpendicular to the front`s orientation as some models such as the HRRR hint at briefly. Again mainly expecting a broken line of showers and a few isolated rumbles of thunder across southern WI this afternoon, but it is still worth mentioning if all the aforementioned factors align, the non-zero chance of a stronger storm or two to keep an eye out for this afternoon. Otherwise, the cold front will slide through the area by this evening and cooler and drier airmass will works its way southeastward this evening and overnight. Looking at more seasonable temps tonight into Tuesday with lows in the mid 40s to lower 50s and highs topping off in the 60s. Tuesday will be drier with lighter winds as high pressure begins to build into the Upper Midwest. Wagner && .LONG TERM... Issued 357 AM CDT Mon Oct 6 2025 Tuesday night through Sunday: Upper level ridging will take hold on the Northern Plains and the exiting upper low will allow for surface high pressure to sit over the Upper Great Lakes Tuesday night through Wednesday night. This will allow for clear skies and calm/light winds, and therefore cooler nights. As the high moves in from Upper Michigan Tue nt, a cold front will drop through southern WI (back door cold front). With 925mb temps dropping to 6 to 8C, overnight lows will have a chance to drop into the upper 30s inland from Lake Michigan. Highs Wednesday will be in the mid 60s which is around normal for this time of year. Wed nt will be another cool night with lows around 40 inland. Winds will become southerly on Thursday with return flow around the high, and a warming trend will return. A shortwave trough is expected to track across the Northern Plains and cross WI Thursday evening. This may give us a brief round of showers. Depending on the speed of that shortwave, the small chance of showers could linger into Friday. Expect high pressure to dominate the region for Saturday and give us a warm anD dry weekend once again with high temperatures well above normal. Cronce && .AVIATION... Issued 1146 AM CDT Mon Oct 6 2025 Cigs of 600-1900 feet behind a cold front are prevalent over east central and much of south central WI and the low Cigs are expected to move into se WI this afternoon. The low Cigs will then last much of the night for all of srn WI. Scattered showers and storms are expected along and behind the front this afternoon then becoming more widespread tnt. Vsbys of 2-5SM BR will develop within any rain areas. Clearing skies are then forecast from nw to se across srn WI Tue AM. Gehring && .MARINE... Issued 357 AM CDT Mon Oct 6 2025 As low pressure tracks across Hudson Bay region through the day, its associated cold front will make its way down across Lake Michigan. Expect lighter south- southwesterly winds ahead to turn northerly behind the cold front passage and exit southern Lake Michigan by this evening. High pressure builds into the Upper Midwest Tuesday and settles over the Great Lakes Region through midweek resulting in lighter, varying winds. Increasing southerly winds return for the end of the week as the high pressure gradually slides further east. Wagner && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...None. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, X, and YouTube at: www.facebook.com/NWSMilwaukee www.x.com/NWSMilwaukee www.youtube.com/NWSMilwaukee