Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
244 FXUS63 KMKX 140936 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 436 AM CDT Wed Aug 14 2024 .KEY MESSAGES... - Dense Fog has developed across southeastern Wisconsin early this morning. Dense fog is expected to persist until day break. - Two rounds of showers and thunderstorms are expected across the region from late Wednesday night through Thursday. Heavy downpours will be possible in all storms. A few strong to severe storms are possible Thursday afternoon and evening. - Gusty southeast winds and building waves on Lake Michigan will create conditions hazardous to small crafts and beach goers Thursday into Thursday night. Both a Small Craft Advisory and Beach Hazard Statement are in effect. - Scattered shower and thunder chances continue Friday through this weekend. && .SHORT TERM... Issued 436 AM CDT Wed Aug 14 2024 Today through Thursday night: Clear skies, light winds and high dewpoints have fog to develop across southern Wisconsin. For many areas fog is expected to remain patchy. Southeastern Wisconsin has seen more widespread and dense fog begin to develop as the dewpoint depressions remain at zero for the last couple hours. Expect this dense fog to remain in place until sunrise when temperatures and mixing will begin to increase. Not out of the question to see this area of dense fog continue to spread out to adjacent counties as much of it is contained to areas east of the Kettle Moraine at this time. A Dense Fog Advisory is in effect for southeastern Wisconsin through day break. Once the fog has burned off this morning, quiet conditions are expected to remain throughout the day today. High pressure is moving out to our east while low pressure from the northern plains advances toward the state. As these two features move largely eastward today, southeasterly winds will pickup becoming gusty overnight tonight into Thursday. Rain and storm chances increase Wednesday night through Thursday as the low pressure system moves into the state. With 60-80% POPs start early Thursday morning and continuing throughout the day which will be the best timing for rain for many areas. These showers and storms will move from west to east along a wing of warm air advection late Wednesday with most of southern Wisconsin expected to remain dry until after midnight outside of far southwestern WI. Instability will be weaker during this time so not anticipating an severe storms with this first round. PWAT values continue to be high around 1.5 to 2 inches Wednesday night and Thursday. Heavy rain will be the biggest threat from this system as a hole but particularly overnight this and lightning will be the main hazards. The flooding potential will be low due to this system being more progressive with the steering flow around 20-30 knots. Once the first round of rain and storms has ended there is expected to be a lull in the precipitation around Thursday afternoon. There is uncertainty in how much of a lull this could be. The length of this lull period will depend on how much the environment gets worked over during the first round and the placement/location of the cold front. The cold/occluded front will be the main sfc forcing mechanism for this second round of storms Thursday evening. A few strong to severe storms will be possible with this second round with the main concerns being heavy rain, hail and strong winds. There is a small chance for some brief tornadoes, but these chances are very low. The main question for any strong to severe storms chances will be dependent on the available CAPE and shear. The better shear looks to stay south of the WI/IL line and the proximity to the low pressure system looks to keep cloud cover over the area. Any clearing that occurs could increase our CAPE enough to get some taller storms. Patterson && .LONG TERM... Issued 436 AM CDT Wed Aug 14 2024 Friday through Tuesday: As the sfc low pressure system and cold front move out of the state Friday, shower/storm chances are expected to decrease to around 25% or less for much of the forecast area. The upper level trough will still slowly be swinging through the Great Lakes Region which should give us enough lift or support scattered to isolated chances for showers and storms. With the better lift and support, especially low to mid level, moving out of the region not expecting much in the way of stronger to severe storms both Friday and Saturday. Drier conditions are expected to return Sunday into mid next week as ridging begins to build in from the west. There is some uncertainty on how long this drier period is expected to last as guidance suggests some shortwaves moving through the flow. Patterson && .AVIATION... Issued 436 AM CDT Wed Aug 14 2024 With light winds and clear skies early this morning patchy fog is expected to develop across portions of southern Wisconsin. Areas east of the Kettle Moraine have the best chances for some patchy dense fog this morning. Low lying areas and river valleys will be the most susceptible for both fog and dense fog development. Any fog that develops is expected to burn off around day break. Widespread VFR conditions will return once the fog has burned off later this morning. Mid to upper level clouds will begin to build in from the west this afternoon and evening. Lower MVFR to IFR ceilings are expected to move in with the rain late Wednesday night and Thursday morning. Heavy rain will be possible with any thunderstorm through Thursday which could drop visibilities. The light and variable winds this morning will become southeasterly by early this afternoon. Southeast winds are expected into increase becoming gusty overnight tonight into Thursday. Gusts up to 30 kt (35 MPH) will be possible. Patterson && .MARINE... Issued 436 AM CDT Wed Aug 14 2024 Light and variable winds are expected to continue across the lake through this morning, as high pressure around 30.1 inches moves east across the region. As this high pressure exits, southeast winds are expected to develop. Overnight into Thursday, southeast winds are expected to increase becoming gusty with gusts up to 30 kts. Gusts are expected to remain below gale force. The gusty winds and building waves will create hazardous conditions for Small Crafts and beachgoers. Both a Small Craft Advisory and Beach Hazard statement are in effect Thursday through Thursday night. Two rounds of showers and thunderstorms are expected from late Wednesday night through Thursday evening. A few storms moving across the open waters Thursday afternoon and evening could become strong to severe, with large hail and gusty winds being the primary hazards. Patterson && .MKX WATCHES/WARNINGS/ADVISORIES... WI...Dense Fog Advisory...WIZ059-WIZ060-WIZ065-WIZ066-WIZ070-WIZ071- WIZ072 until 8 AM Wednesday. Beach Hazards Statement...WIZ052-WIZ060...7 AM Thursday to 7 AM Friday. Beach Hazards Statement...WIZ066-WIZ071-WIZ072...7 AM Thursday to 1 AM Friday. LM...Small Craft Advisory...LMZ643-LMZ644...7 AM Thursday to 7 AM Friday. Small Craft Advisory...LMZ645-LMZ646...7 AM Thursday to 1 AM 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