007 FXUS63 KDTX 151653 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 1253 PM EDT Sun Mar 15 2020 .AVIATION... VFR through the period with stout NE/ENE wind today giving way to light flow out of the SE quadrant overnight courtesy of nocturnal stabilization and high pressure departing from Ontario. For DTW...Potential noise abatement issues with ENE flow around 10 kts continuing through this aftn. A few clouds around 5kft possible by mid-morning Mon as moisture over the Ohio Valley lifts north.. .DTW THRESHOLD PROBABILITIES... * None && .PREV DISCUSSION... Issued at 336 AM EDT Sun Mar 15 2020 DISCUSSION... A strong low to mid level anticylone will expand across the northern Great Lakes this morning. The center of the 850mb high will traverse Lower Mi this morning, while the sfc high tracks across northern Ontario into Quebec. The resulting mid level subsidence and advection of very dry low level air associated with the circulation around the sfc high will sustain the ongoing clearing trend across Se Mi through daybreak. Shallow cold air advection will limit daytime mixing depths to a degree. Accounting for full mid March sun this afternoon will still boost afternoon highs into the low 40s. The exception will be across the thumb and Saginaw Valley where the flow off Lake Huron will suppress highs into the 30s. With the sfc high exiting the Great Lakes region to the east, there will be a low level gradient present over Se Mi tonight as the winds veer from northeast to south. In light of the extremely dry air overhead and clear skies, radiational cooling should still prove efficient enough to drop min temps into the upper teens/low 20s. Southerly return flow on Monday will boost afternoon highs well into the 40s. The daytime highs will however be limited to a degree by increasing cloud cover as the region of low level moisture across the Lower Ohio Valley is driven into Se Mi. While the depth of moisture per model soundings does not look too impressive, subtle moist isentropic ascent and steepening mid level lapse rates may be enough to generate some light rain showers/sprinkles late Mon afternoon and evening. A fairly strong northern stream mid level wave is then forecast to advance across the northern Great Lakes late Mon night/Tuesday morning. The better mid level DCVA, height falls bullseye and upper jet dynamics will be targeted across northern Michigan. There will still be some semblance of large scale ascent across Se Mi. This coupled with the steep lapse rates will support a chance for some rain/snow showers. The coverage/chances will be limited by the overall poor moisture quality across Se Mi. This system will force colder air across the region on Tuesday. Daytime mixing will be offset the cold air to a degree and will still support high temps in the 40s under somewhat gusty west- northwest winds. A split flow continues to be forecast by the medium range model suite for the later half of the week. There is the potential for multiple waves to eject out of the upper low over the swrn US and lift into the Ohio Valley/Great Lakes region Wed night into Friday. These waves will drive ample deep layer moisture into a tightening baroclinic zone across the region and will support increased chances for precip. Se Mi is forecast to remain far enough into the warm air to where most of the precip looks to be in the form of rain. MARINE... Strong high pressure tracks across northern Ontario today with modest northeast wind continuing across the central Great Lakes through the day. The long fetch across Lake Huron and onshore flow will allow for waves on the order of 3 to 5 feet to persist across the northern Thumb and Outer Saginaw Bay nearshore waters today, and a Small Craft Advisory remains in effect. The gradient eases by this afternoon as the high moves into southern Quebec and begins to weaken. Winds remain below 15 knots and veer to southerly on Monday. A cold front then moves through the Great Lakes on Tuesday with unsettled marine conditions accompanying it. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...Small Craft Advisory until 4 PM EDT this afternoon for LHZ421-441- 442. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....JVC DISCUSSION...SC MARINE.......TF You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.