115 FXUS63 KDTX 100905 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 505 AM EDT Tue Jun 10 2025 .KEY MESSAGES... - A chance for a light shower with slightly below normal temperatures. - Much warmer weather is expected on Wednesday with highs well into the 80s. - A frontal boundary hanging around the area will lead to periodic chance of showers and thunderstorms Wednesday night through Saturday. && .AVIATION... Clear or mostly clear skies start the forecast period before remnant strato-cu currently over northern WI invigorates diurnal cu development across the region late morning into the afternoon. Coverage varies between SCT to BKN through the afternoon-evening with ceilings holding around 5kft. Despite increasing cloud cover, diurnal mixing will support westerly wind gusts near or slightly over 20kts throughout the bulk of the daylight hours. Winds then weaken tonight with the loss of daytime heating in addition to dissipating the lingering cu field. For DTW/D21 Convection...No thunderstorms expected through the period. THRESHOLD PROBABILITIES... * Medium in ceilings at or below 5000 feet late this morning through early evening. Low by late evening. && .PREV DISCUSSION... Issued at 332 AM EDT Tue Jun 10 2025 DISCUSSION... Large wavelength low pressure now centered over portions of Lake Superior and the eastern U.P. will steadily fill today as the system transitions into an open wave. Phasing of the upper level trough with southern stream jet energy over the mid Atlantic will also cause it to accelerate as it pushes into Quebec late this morning. The wavelength is great enough to keep the heart of the midlevel cold air, 775mb temperatures of approximately 2-3C, in place throughout much of the daylight hours. Models have been consistent in enough lower tropospheric moisture to allow for some modest instability, 250 J/kg, centered at 5.0-6.0 kft agl this afternoon. Some conflicting model signal on whether or not free convection will be possible but the cumulus response should be fairly robust. The chance for iso-scattered showers exist after 20Z and will maintain the potential for a rumble of thunder in the Thumb. The main narrative for today may be the breezy west winds of 15 to 25 mph. This flow will aid deep mechanical mixing that should help temperatures overachieve slightly into the low-mid 70s. The exiting upper level trough will allow geopotential heights to rise over Lower Michigan differentially. Increased thickness will allow for a surge in temperatures Wednesday with the latest guidance suggesting solid low to mid 80s. A notable increase in humidity is also anticipated with surface dewpoints in the upper 50s to around 60 degrees. Despite the moisture forecast soundings support active subsidence and associated capping/CIN in the 3.5 to 8.0 kft agl layer. It remains difficult to envision a scenario with precipitation Wednesday. Models remain steadfast in suggesting that a strongly stable surface anticyclone will build into portions of northwestern and northern Ontario Thursday before slowing and putting on the brakes. In fact, the models suggest it may take until Sunday for the center of the surface high to push through Quebec. The positioning of this is favorable for the development of easterly flow over the central Great Lakes with a lake modification component allowing a quasi- stationary baroclinic zone settling and sharpening over Lower Michigan. Widely varying heat and humidity is anticipated across this boundary. High uncertainty and low confidence exists in both where activity will develop along this boundary and whether or not any larger scale MCS systems will track along it. Alot of boom or bust potential exists with this boundary. Still a long ways away to provide much commentary and will refrain from any dry periods. MARINE... Outside of some elevated winds and gust around 20 to 25 knots through the Saginaw Bay this morning with the favorable southwest fetch, lighter winds will prevail for the remaining locations across the Great Lakes as the pressure gradient eases in the wake of a cold front. Outside of an isolated light pop up shower, dry conditions prevail today. A warm front will then bring the chance for elevated showers mainly for northern Lake Huron tomorrow and will again produce some favorable southwest fetch for the Saginaw Bay which bring additional chances to see winds aoa 20 knots. The frontal boundary will then stall across the central Great Lakes which will be the focal point for repeated shower and thunderstorm activity through the midweek period. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...Small Craft Advisory until 10 AM EDT this morning for LHZ421-422. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ AVIATION.....KDK DISCUSSION...CB MARINE.......AM You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.