Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI
Issued by NWS Detroit/Pontiac, MI
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607 FXUS63 KDTX 160753 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 353 AM EDT Mon Sep 16 2024 .KEY MESSAGES... - Seasonably warm and dry conditions prevail through the week. - High temperatures remain above normal but settle into the upper 70s with a cloud increase during mid week. - Readings return to the lower 80s Friday into next weekend. && .DISCUSSION... We begin the week with more of the same outstanding mid September weather across SE Mi as surface high pressure combines with a blocking ridge aloft to produce clear sky over the region today. Full sun is also still made hazy by some lingering high altitude forest fire smoke that has been slow to dissipate within the weak wind profile. High temperatures in the lower to mid 80s return this afternoon with readings at the cooler end of the range toward the Huron and Erie shorelines. After a repeat performance Tuesday, the forecast highlight is on the Mid Atlantic tropical system and its evolution during the mid to late week period. Model trends still cast some uncertainty on favored solutions due to a fair amount of spread still shown on the westward extent of the 500 mb circulation and moisture field. The 00Z GFS run made a noticeable shift to a slower/farther south solution more in line with the ECMWF vs the farther north NAM and Canadian runs. All of the regional and global deterministic models are in much better agreement on energetic split 500 mb flow over the west half of North America and show solid predictability through little to no variation over the last several model runs. The favored larger scale downstream influence from the Rockies long wave trough reinforces the ridge portion of the rex block across Ontario and the Great Lakes. This in turn holds low pressure farther south and eventually east, and trends the SE Mi forecast away from measurable rain during the Wednesday time period. Late week evolution of the large scale pattern also results temperatures a few degrees cooler but still above normal into next weekend. The overall strength of the rex ridge settles from about 588 dm height to about 582 dm by Wednesday into Thursday. The associated thickness cooling then trims a few degrees off high temperatures compared to recent days. Guidance hovering in the upper 70s to lower 80s looks reasonable through the period. && .MARINE... High pressure continues to dominate conditions across the central Great Lakes through the first half of the week. Light (aob 15kts) southerly flow holds through today before turning back to more easterly for the midweek period. && .PREV DISCUSSION... Issued at 1157 PM EDT Sun Sep 15 2024 AVIATION... Expansive area of high pressure maintains influence this period. This ensures dry and stable conditions, precluding lower cloud development. Shallow ground fog will again be possible at daybreak Monday due to favorable radiative cooling conditions. Light winds generally from the southeast persist. For DTW/D21 Convection... Thunderstorms are not in the forecast for the foreseeable future. DTW THRESHOLD PROBABILITIES... * None. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ DISCUSSION...BT MARINE.......KDK AVIATION.....MR You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.