817 FXUS63 KDTX 141345 AFDDTXArea Forecast Discussion National Weather Service Detroit/Pontiac MI 945 AM EDT Sun Sep 14 2025
.KEY MESSAGES...
- Localized areas of fog upwind of Lake Erie dissipate by noon.
- Much above normal highs with continuing dry weather into next week.
&&
.UPDATE...
Areas of fog have persisted upwind of Lake Erie this morning, still holding vsbys to a quarter mile or less at obs sites closest to the shoreline (TTF and ONZ). Satellite trends have shown a substantial reduction in the fog plume over the last hour or so which should only continue to erode as solar insolation ramps up. Updated grids reflect the localized nature of the fog plume, which should be fully mixed out by noon.
&&
.PREV DISCUSSION... Issued at 545 AM EDT Sun Sep 14 2025
AVIATION...
Scattered areas of fog have developed overnight with the greatest coverages and densities focused over the Thumb and Lake Erie shoreline. Fog near Lake Erie has trended towards a low stratus instead for DTW/YIP. By the start of the new forecast period, this fog (or low stratus) should begin to burn off following sunrise supporting clearer skies by mid morning. Otherwise, region remains under high pressure again today keeping skies mostly clear with any diurnal cu limited to FEW/SCT coverage.
For DTW/D21 Convection... No thunder chances for the period.
THRESHOLD PROBABILITIES...
* Moderate for cigs aob 200ft at start of new forecast period this morning, low by mid-morning.
PREV DISCUSSION... Issued at 347 AM EDT Sun Sep 14 2025
DISCUSSION...
A blocked, high amplitude upper level pattern featured over the next week ensures an extended stretch of benign weather with conditions marked by well above average warmth. This pattern solidified over the next 24 hours as a narrow upper ridge squeezes into the upper midwest and great lakes before closing off. This process occurs as high pressure anchors to the north, maintaining a light easterly gradient to finish the weekend period. Moderating thermal profile within the background of increasing geopotential heights and full insolation yields roughly 2-3 degrees warming across 850-925 mb layer relative to recent days. This translates into highs mainly in the lower 80s, but with the onshore flow contributing to slightly cooler readings for locales within immediate proximity to lake influence. Potential for conditions to again be conducive for some areas of fog development late tonight, particularly across the thumb as light east/northeast flow draws moisture off lake Huron.
Upper level high pressure system peaking around 593 dm will remain fixated over the region through the middle of next week. Neutral thermal advection overall with low level flow generally lacking a southerly component lends to gradual moderation of the resident above average thermal profile given the high magnitude height field. Highs inching upward into the middle to possibly upper 80s by Wed/Thu - or just shy of records levels. Dry conditions persist given the stability, with generally manageable humidity held in check as adequate diurnal mixing maintains a dewpoint near or below 60 degrees. Some indication within extended model output for this pattern to gradually break down next weekend, offering the next opportunity for meaningful rainfall should greater forcing materialize as heights fall.
MARINE...
A ridge of high pressure will build through the day today and will hold through the the middle of the week, bringing an extended period of dry weather along with light winds. Winds direction does turn more uniform this afternoon from the northeast, which will bring some localized gust potential towards 20 knots into the Saginaw Bay given the favorable fetch. These localized higher winds will subside into tomorrow morning.
&&
.DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. &&
$$
UPDATE.......MV AVIATION.....KDK DISCUSSION...MR MARINE.......MR
You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.
NWS DTX Office Area Forecast Discussion