076 FXUS63 KDTX 271941 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 341 PM EDT Mon Sep 27 2021 .DISCUSSION... Cold front is currently over Mid MI slowly drifting southward and will continue to do so through this evening. The front is still expected to exit south of MI shortly after dark around 02-04Z. Weak northerly winds behind the front and weak west-southwesterly flow ahead of the front has resulted in weak convergence and broad/weak fgen around 925-850mb. SPC mesoanalysis shows the strong cap in the morning DTX sounding (and hires model soundings) is holding with around 200-300 CIN. With wealth of dry air above 850mb and weak overall forcing at the end of the diurnal cycle, it still looks like an overall dry frontal passage with only an isolate shower possible. Main affects from the fropa will be enhanced cloud cover and a flip to northerly flow. Lows tonight will drop into the upper 40s north of I69 to mid 50s near the Ohio border. The rest of the week looks quiet weatherwise. A upper level ridge will be advancing eastward across the Plains while narrowing and amplifying into the Plains of Canada. Meanwhile a closed upper low over eastern Canada will be dropping southward over the mid atlantic coast blocking the ridge and stalling it over the western Great Lakes through the mid week period. We should be locked in with northwesterly confluent flow aloft with expansive high pressure building south from Canada. Placement of the surface ridge will keep a light northeasterly winds over the area much of the week, bringing in continuous feed of dry air in the boundary layer. Temps will be near seasonal averages with highs in the low to mid 70s and lows bouncing around on either side of 50. && .MARINE... A frontal boundary will continue to move southward through this evening. This will be a dry frontal passage with winds remaining relatively light. Northeasterly post frontal winds do present an opportunity winds funneling down down Saginaw Bay to produce an occasional gust to around 20 knots. However, expecting conditions to remain below Small Craft Advisory. For the remainder of the week, a high amplitude central United States ridge and a slowly migrating surface high pressure across the Great Lakes region will result in favorable marine conditions. && .PREV DISCUSSION... Issued at 158 PM EDT Mon Sep 27 2021 AVIATION... The surface cold front is along a line from KOSC-KHTL-KLDM. Expanding surface high pressure across the Lake Superior basin will drive the cold front across Southeast Michigan throughout the remainder of the afternoon and evening. An abrupt wind shift to the northeast is expected at all of the terminals after the cold front passage. Cold air advection between 2.5 and 5.0 kft agl will result in saturation and stratus development post front, with bulk of cloud expected to remain at VFR. Aggressive dry air advection will be quick on the heels resulting in a return to SKC between 09-12Z Tuesday. DTW THRESHOLD PROBABILITIES... * Moderate for ceilings 5000 ft or less Monday evening into early Tuesday morning. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...NONE. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ DISCUSSION...DRK MARINE.......AA AVIATION.....CB You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.