327 FXUS63 KMKX 110220 AAA AFDMKX Area Forecast Discussion...UPDATED National Weather Service Milwaukee/Sullivan WI 920 PM CDT Tue Jun 10 2025 .KEY MESSAGES... - Temperatures rise into the upper 70s to middle 80s Wednesday, with mostly dry weather during the day. - Periodic shower and thunderstorm chances are forecast from Wednesday evening through Saturday, though there will be some dry periods. Cannot rule out a few stronger storms during this period. - Conditions look a bit drier by later this weekend. && .UPDATE... Issued 920 PM CDT Tue Jun 10 2025 Skies have cleared out this evening, and any lingering smoke in northeast parts of the area should push off to the east by the overnight hours. Warm air advection will develop overnight into Wednesday, as southwest winds at the surface increase with a tightening pressure gradient. A cold front will approach the area from the northwest later tonight into Wednesday morning, and may combine with the warm air advection to bring some clouds and perhaps an isolated shower/sprinkle or two into Wednesday morning. However, there is limited moisture to work with, so uncertain if anything will develop. Wednesday will be warm south of the front, with highs into the middle 80s with dew points around 60 degrees. Highs may be a little cooler north of the front, in the upper 70s to around 80 degrees. The front should move south into the area and stall west to east in southern portions of the area by later Wednesday afternoon into Wednesday evening. The low level jet nose remains to the wets of the area. Thus, CAMs are suggesting that there may be weakening showers and storms that move east into the area during this time, as mean layer CAPE weakens quite a bit in the evening. Brief gusty winds and small hail may occur in any storm that can sustain itself, but this may be few and far between. There is a trend with any thunderstorms having trouble holding together with successive CAM runs, so changes to PoPs are expected as we get closer to Wednesday evening. Wood && .SHORT TERM... Issued 250 PM CDT Tue Jun 10 2025 Tonight through Thursday night: Weak high pressure overhead through tonight with clear skies for the most part overnight. Weak ridging overhead will help keep the region dry through tonight. Into Wednesday mostly zonal flow aloft will allow for some shortwave activity to slide in off the weak ridging to the west into the region. The low to mid level moisture will be fairly poor with perhaps a shower or two but likely remaining dry through at least the morning and likely through most of the afternoon as well. Into the evening better moisture in the mid-levels fills in with shortwave activity continuing through the region and likely bringing a period of showers/storms Wednesday evening and overnight with some focus along the warm front that will lift into the region. Instability looks likely to be fairly limited to the southern parts of the CWA when this comes through in large part due to timing but with decent deep layer shear we cannot rule out a stronger storm or two but primarily earlier in the evening. There remains some uncertainty on exactly where the rain sets up but best chances will remain in the western parts of the CWA Into Thursday morning the potential for showers will continue across much of the CWA as the warm front stagnates across southern WI. There is definitely uncertainty on exactly how this will unravel into Thursday as we will likely see at least periods of dryness Thursday, perhaps moreso during the late morning and early afternoon with some lingering shower activity from the overnight for the early morning period. While models continue to have the surface front over the region Thursday the model trends push the 850mb front further north with better forcing from the LLJ and help from the upper wave. In this scenario we would be more likely to remain drier with the primary forcing being from the surface front though the mid-levels would be on the drier side. If the 850mb front fails to push further north that could easily bring us back into a better regional area for the modeled events to our north and west. In that scenario we could see some storms and even some stronger ones in addition to some good rainfall with PWATs in the 1.25 to 1.75 in range. The CAMs that stretch out that far suggest the showers lingering into the early morning with some chances in the afternoon evening but focused further north. This largely aligns with the current thought process but with so much uncertainty in this situation the forecast will remain fluid. Kuroski && .LONG TERM... Issued 305 PM CDT Tue Jun 10 2025 Friday through Tuesday: The same surface frontal feature mentioned in the SHORT TERM section of this AFD will remain nearby through the rest of the extended forecast, waffling north / south and producing occasional shower and thunderstorm chances. There is a signal for a surface low to develop over southern MN pre- dawn Friday and track eastward, producing 60-80% rain chances through the daytime hours of Friday, with only 20-40% chances for showers / storms to continue into Saturday (which the GFS and ECMWF suggest will be briefly dominated by high pressure tracking behind the low). We kept precip chances low (10-20%) into Sunday given the potential for the aforementioned high pressure to hold the surface frontal zone far enough south to leave us dry. Though predictability remains low, there is modest agreement for the 500-250mb ridge over the northern Plains to gradually build deeper towards our region, suggesting that a gradual warming trend is likely late this upcoming weekend into early next week. Sheppard && .AVIATION... Issued 920 PM CDT Tue Jun 10 2025 Skies have cleared out this evening, and any lingering smoke in northeast parts of the area should push off to the east by the overnight hours. Southwest winds will gradually increase into Wednesday morning. Some gusts to around 20 knots are possible. There may be a brief period of low level wind shear later tonight into Wednesday morning, mainly between 09Z and 14Z across most terminals except Janesville and Kenosha. 2000 foot AGL winds should be southwest around 40 to 45 knots. A cold front will approach the area from the northwest later tonight into Wednesday morning, and may bring some clouds and perhaps an isolated shower/sprinkle or two into Wednesday morning. However, there is limited moisture to work with, so uncertain if anything will develop. The front should move south into the area and stall west to east in southern portions of the area by later Wednesday afternoon into Wednesday evening. There may be weakening showers and storms that move east into the area during this time. Winds will weaken as the front moves in. There is a trend with any thunderstorms having trouble holding together Wednesday evening, so may hold off on any thunder mention for now. Wood && .MARINE... Issued 920 PM CDT Tue Jun 10 2025 Low pressure around 29.5 inches in Ontario will linger across the northern Great Lakes Region through Wednesday, gradually sliding east. Meanwhile, high pressure around 30.2 inches will stagnate across the Ohio Valley region. Light to moderate southwest to west winds are expected across the lake between these two systems into Wednesday. Dry weather is expected through midday Wednesday as well. Southwest winds may approach Small Craft Advisory levels into Wednesday morning, with gusts to around 22 knots or so possible. Heading into Wednesday evening, a cold front will drop south down the lake and become stationary across the far southern end on Thursday. This frontal boundary will remain draped across the far southern lake until Friday, when a low pressure system around 29.5 inches moves into central Wisconsin from the Rockies. Multiple rounds of showers and thunderstorms will be possible from Wednesday evening through Friday, though the better chances will remain to the west. Light north to northeast winds are expected behind the cold front Wednesday evening. When the front stalls, areas north of the boundary will have light northeast winds and areas to the south will have light southeast winds. Winds across the lake will increase slightly Thursday night into Friday and become easterly, as the low approaches. No gales expected at this time. Kuroski/Wood && .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