648 FXUS63 KDTX 010825 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 425 AM EDT Sat Apr 1 2023 .DISCUSSION... The front has swept through southeast Michigan early this morning with westerly flow taking over and pushing the widespread rainfall and scattered thunderstorms. The wind gust potential will remain through this morning tied some cold advection with gusts of 25-35 mph occuring across most of southeast Michigan at press time. The better lower to mid level cold advection will be trailing behind the front and arrive during the 12-18Z period. This leaves a largely stable surface layer becoming reestablished with a depth of over 1 km as strong lower level jet flow of 30-40 knots holds overhead. The greater wind gust potential associated with the cold air advection should come after 12Z. The potent mid level trough moves directly over central lower Michigan this morning and afternoon. The associated surface low is elongated across the central and eastern Great Lakes. The subsequent wind field around this trough and surface pattern brings the better low level wind fields across the southern portions of the areas near the Ohio border where 30-50 knots winds will be present around 850 mb from 12-18Z today. The better mixing develops by around 14Z and continues into the afternoon while some scattered precipitation also begin to develop. This precipitation will be supported by the main vorticity max and the cold temperatures of -25C at 500 mb with this trough. Some SBCAPE of a few hundred j/kg looks like it may be able to develop in the morning bringing a slight chance for thunderstorms. So in addition to the daytime mixing, these showers/thunderstorms will have potential to pull down some of the stronger lower level winds as well. Guidance has been trending down slightly overall in latest runs across the southern areas, but moderate to high confidence exists for gusts of 30 to 40 mph across Lenawee and Monroe county between 14Z and 18Z. Winds across the metro area north to the Tri- Cities should be mostly at or below 30-35 mph with the possibility for higher gusts associated with any thunderstorm. Winds across the northern Thumb region will be 30 to 40 mph gusts for much of the day. Precipitation chances wane during the mid to late afternoon as the trough moves into the eastern Great Lakes and deep layer northwest to north flow takes hold. There will be a chance for light snow to mix across northern portions of the CWA before precipitation ends by 00Z. The northerly flow will usher in 850 mb temperatures approaching -10C by 12Z Sunday. The cold airmass will be supportive of Sunday morning lows in the mid 20s. A high pressure and low level ridge will move across the central Great Lakes Sunday morning as well lead to dry conditions that will last through the remainder of the day. Zonal flow aloft with southwest to south lower level will draw warmer air into southeast Michigan throughout the day and allow most of the area to rebound into the mid-upper 40s for daytime highs. A long wave ridge will develop in response to a PacNW trough building into the Rockies during the early to mid week period. This will lead to a warming temperatures during this time with daytime highs on Monday climbing into the 60s and an eventual making a run to around 70 degrees for Wednesday. There will be increasing chances for rain during the later part of the day Sunday as 850 mb moisture transport ramps up atop a warm frontal boundary draped across IL to OH. A trough will eventually eject out of the Rockies on Tuesday resulting in surface cyclogenesis across the central Plains. This system will lift across the Midwest and Great Lakes Tuesday evening into Wednesday bringing the next chance for widespread precipitation and thunderstorm chances. && .MARINE... A warm front associated with a strong low pressure system will continue lifting slowly northward through the central Great Lakes the remainder of tonight. Meanwhile, a strong surface low will track further northeastward from central Lake Huron and eventually into the St. Lawrence River valley by late in the day today as it deepens further into the mid 980s hPa. Strong cold air advection behind the system cold front passage along with a northerly wind shift will lead to a period of gales for the Lake Huron basin. Gale Warnings are in effect for all of Lake Huron with Small Craft Advisories for Lake St. Clair and western Lake Erie this morning into the evening. Wind speeds will rapidly decrease tonight as high pressure from the upper Midwest builds into the Great Lakes and ends the threat for gales. As the high pressure drifts southeast throughout the day Sunday, another low pressure system moving across the northern Great Lakes Monday will bring an increase in winds speeds again approaching gale strength. && .PREV DISCUSSION... Issued at 130 AM EDT Sat Apr 1 2023 AVIATION... The strong low pressure system will continue tracking northeastward across Lake Michigan, and eventually central Lake Huron and into the St. Lawrence River valley the remainder of tonight and into Saturday. The system cold front will track through the airspace between 06z-08z bringing the final round of heavy rain and thunderstorms before precip comes to a rapid end with the arrival of the system dry slot. IFR and LIFR flying conditions will remain possible for a few hours before flying conditions rapidly improve to VFR for the remainder of tonight. MVFR ceilings likely return as post-frontal cold air advection sets in, with expansive cloud persisting for the balance of the day. High pressure then builds into the Great Lakes by Saturday night allowing for clouds to rapidly scour out. Southerly winds will ramp up ahead of the cold front passage tonight, veering southwesterly with gusts approaching 30 knots. Winds will further veer to the west/northwest Saturday with peak gusts up to 35 knots before diminishing quickly to around 10 knots by Saturday evening. For DTW...Thunderstorms will continue to remain possible through 08z along with IFR flying conditions primarily of ceiling nature. There will be the potential for crosswinds Saturday afternoon with gusts around 30 knots. DTW THRESHOLD PROBABILITIES... * High in ceilings below 5000 feet through 09z. Low remainder of tonight. High again bulk of the day Saturday. * Moderate in thunderstorms through 08z. * Moderate for west to northwest crosswinds Saturday afternoon. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...Gale Warning until 10 PM EDT this evening for LHZ361-362. Gale Warning from 2 PM this afternoon to 10 PM EDT this evening for LHZ363-421-422-441>443-462>464. Lake St Clair...Small Craft Advisory from 10 AM this morning to 10 PM EDT this evening for LCZ460. Michigan waters of Lake Erie...Small Craft Advisory until 10 PM EDT this evening for LEZ444. && $$ DISCUSSION...AA MARINE.......IRL/AA AVIATION.....IRL You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.