Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
031 FXUS63 KMKX 291434 AAA AFDMKX Area Forecast Discussion...UPDATED National Weather Service Milwaukee/Sullivan WI 934 AM CDT Sat Jun 29 2024 .KEY MESSAGES... - Small chance for a shower or thunderstorm to develop across parts of the area this afternoon along the cold front. - River flooding and high water levels remain elevated into next week. Additional rises will be possible with any heavier rainfall. - Breezy northwest to north winds will become hazardous to Small Craft tonight into Sunday morning. && .UPDATE... Issued 934 AM CDT Sat Jun 29 2024 Low clouds are lingering across the area, and may take several hours to scatter out, which is still anticipated by early this afternoon. The initial surface trough has moved through the area, as winds have shifted to the west with some gustiness. The main cold front is still pushing southeast through Wisconsin, and may help generate a few showers and/or storms this afternoon. There should be 1000 to 1500 J/kg of mean layer CAPE with around 40 knots of deep layer bulk shear, capped somewhat by the warm low levels. Could see gusty winds and small hail with a stronger storm, if they can form. The main 500 mb shortwave trough is expected to remain well north of the area this afternoon, so its influence may be confined there as well. CAMs suggest that any activity would be isolated to widely scattered, and may be limited to north of the forecast area. Will continue to mention smaller PoPs for this potential this afternoon, highest toward the northern and northeastern parts of the area. Otherwise, a warm and humid day is expected until the main cold front passes through, with highs into the lower to middle 80s. Wood && .SHORT TERM... Issued 431 AM CDT Sat Jun 29 2024 Today and Tonight: With the rest of the MCV to the east and larger scale subsidence settling in across southern Wisconsin, dry conditions have returned. Two cold fronts are still to our west early this morning in eastern MN and western central WI. Both cold fronts will shift eastward and move through the state today. The first front will move through southern Wisconsin this morning bringing some clearing skies and lower dewpoints. Behind the front the clear skies will increase instability a bit with CAPE values expected to climb to around 1000-1500 J/kg. While dewpoints will drop slightly they should remain around 60 degrees. In an environment with roughly 30 knots of shear, any mesoscale lifting has the potential to develop some scattered rain showers and storms. As the secondary cold front moves through this will bring the best potential for a few rain showers to develop this afternoon. The chances are low due to the uncertainty that we will get the instability, shear, lift and enough moisture all lining up at the right time when the front comes through. Guidance has reflected this low chance by having previous runs not even acknowledge these chances. The latest CAMs this morning have finally started to recognize this low threat for rain and storms early this morning which does increase confidence slightly. POPs this afternoon remain around 20-25%. If any storms due develop across portions of south central and east central Wisconsin then there will be a potential for some gusty winds and small hail. Sounding have a very dry low level profile which will help with the downburst potential. Patterson && .LONG TERM... Issued 431 AM CDT Sat Jun 29 2024 Sunday through Friday: High pressure will begin to build into the Great Lakes Region from the Northern Plains Sunday into Monday. This will bring dry weather and cooler conditions back to southern Wisconsin. The coolest day will be Sunday where high temperatures struggle to climb into the low 70s. As the high pressure system begins to move overhead Monday, southerly winds return bringing some weak WAA back to the state. This will cause temperatures to increase slightly with highs in the low to mid 70s. This brief period of quiet weather will come to an end Tuesday. Tuesday through Friday a more active pattern once again sets up across the state. A few upper level troughs and pulses of PVA are expected to move through the Great Lakes Region during this time. This pattern will promote multiple frontal passages and the sustained southerly winds will allow persistent WAA. Given all of this, southern Wisconsin again looks to be in a situation with warm and moist conditions. This could lead to near daily chances for rainfall. Due to this guidance has painted in broad brushed POPs Tuesday through Friday. Don`t expect any day to be a complete wash out at this time, so worth keep an eye on this time period to see where the best chance for rain line up. Patterson && .AVIATION... Issued 934 AM CDT Sat Jun 29 2024 Low ceilings are expected to gradually mix upward and scatter out by early this afternoon across the area. Westerly winds with gusts to around 15 knots are expected as well, veering northwesterly later this afternoon and early this evening, as the main cold front moves through. May see a shower or thunderstorm develop with the frontal passage this afternoon, though uncertain if this will occur. Sheboygan would have the better chances of seeing any activity, but will not mention in TAFs at this time. Gusty northwest winds are expected tonight, becoming north Sunday and weakening. Winds should shift northeast for terminals near Lake Michigan by Sunday afternoon, with some gusts to 15 knots or so. May see some diurnal cumulus clouds develop Sunday afternoon. Wood && .MARINE... Issued 431 AM CDT Sat Jun 29 2024 South to southeast winds will continue early this morning as low pressure of 29.5 inches moves eastward across the northern Great Lakes Region. A pair of cold fronts will slide southeast today causing winds to shift to southwesterly by midday, and then northwest by the evening. Gusty northwest winds are then expected tonight through Sunday. A Small Craft Advisory is in effect during this time for the gusty northwest winds. Northwest winds will weaken Sunday night into Monday and become northeast to easterly as high pressure of 30.3 inches builds in from the Northern Plains. Patterson && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...7 PM Saturday to 9 AM Sunday. && $$ 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