835 FXUS63 KDTX 050728 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 328 AM EDT Sat Apr 5 2025 .KEY MESSAGES... - Widely scattered rain showers continue this morning. - Cooler conditions persist early next week with snow showers likely on Monday. && .DISCUSSION... The broad synoptic pattern remains intact this morning with the core of a 40 knot llj lifting northward across SE MI. Embedded on the nose of the jet is a zone of broad inertial momentum and enhanced ageostrophic flow. This feature aligns with the wider corridor of light rainfall enhancement see on radar which has become increasingly focused from the Flint region into the Tri- Cities and northeast through the Thumb. Latest trends suggests that any QPF maximum will be co-located with this feature with localized totals potentially exceeding a half-inch, where forcing and moisture convergence is maximized. For locations south, precipitation coverage has been significantly hampered due to early morning convection south of the state line which muted the degree of Gulf moisture into Michigan. This is also observed within the VAD profiler which shows the strength of the llj never lived up to model projections, reducing the magnitude of moisture advection. Additionally, the main arc of moisture transport and deeper PW remains displaced south of Michigan. Isolated to scattered shower development will remain possible through the morning, but qpf totals have been revised downward to a quarter-inch or less. The stronger forcing associated with the inertial momentum over the northern half of the cwa will exit by 12Z, but lingering showers remain possible through the late morning hours with a trailing cold front. For the afternoon and evening, a chance for lingering rain showers will be retained roughly from a line around and south from Port Huron to Adrian given the interaction with a glancing shortwave and departing moisture axis. It will be competing with increasing cold and dry air advection which limits PoP chances and ends the limited rain chances by early Sunday morning. Diffuse area of high pressure produces dry weather tomorrow while temperatures in the wake of the cold front peak in the upper 40s. In fact Sunday will likely be the warmest day of the early week period once an upper-level wave carves into the Midwest, reinforcing a strong thermal trough characterized by h850 temperatures of -14C, which set up over SE MI by Tuesday morning. Highs will be highly variable across SE MI on Monday as the daytime passage of an associated cold front supports highs in the upper 30s across the Tri- Cities and Thumb with another chance to see upper 40s for the Metro region. Once the cwa is firmly entrenched under the thermal trough, lows in the low 20s Tuesday only warm into the upper 30s by Tuesday afternoon. Additionally, the aforementioned wave likely bring widespread wintry precipitation to most of the region through the day Monday. 850mb temperatures well below freezing across the forecast areas with some wbz levels above 1kft for portions of the Metro region support snow or a rain/snow mix before a brief transition to all snow. At present time model analysis shows unfavorable timing of snow potential during daylight hours. Given warmer soil temperatures and the April sun angle, light wintry accumulation would be retained to grassy surfaces, or some slushy accumulation on roadways for portions of the Tri-Cities and Thumb. && .MARINE... Widespread rain showers and possible embedded weak thunderstorms over Lake St. Clair and Lake Erie will slowly taper off today as a wave of low pressure tracks in between the Central and Eastern Great lakes. Increasing northwest winds following for this afternoon- evening. Good surge of low level cold advection, as 850 MB temps drop to around -10 C over northern Lake Huron, promoting deep mixing and wind gusts of 30-35 knots for a short period during the evening. A brief period of wind gusts near 25 knots over Saginaw Bay and northern tip of the Thumb region. Light winds return for Sunday before a clipper system tracks through on Monday producing a period of snow and rain showers. Even colder air will follow this system and northwest wind gusts around 30 knots appear likely over much of Lake Huron for Monday evening. && .PREV DISCUSSION... Issued at 1203 AM EDT Sat Apr 5 2025 AVIATION... Fragile patches of light rain during late evening fill in with greater coverage and intensity after midnight. This is accompanied by northward advancement of MVFR ceiling as low level dry air from east wind is gradually overcome. A transition to IFR/LIFR follows later in the night as showers increase coverage intensity, and then as the surface low approaches NW Ohio. A rumble of thunder remains possible near to the south of DTW and more likely south of the Ohio border during the late night. This will be monitored as the surface low ripples along the warm front south of a TOL to CLE line early in the morning. Passage of the low brings wind around to the NW across Lower Mi leading to a slow ceiling improvement through afternoon into Saturday evening. DTW THRESHOLD PROBABILITIES... * High for ceiling 5000 feet or less late tonight and Saturday. * Low for thunderstorms late tonight. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ DISCUSSION...AM MARINE.......AM AVIATION.....BT You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.