833 FXUS63 KDTX 151851 AFDDTXArea Forecast Discussion National Weather Service Detroit/Pontiac MI 251 PM EDT Mon Sep 15 2025
.KEY MESSAGES...
- Patchy-Areas of fog, locally dense late tonight.
- Above normal high temperatures continue into the weekend.
- Dry weather through the first half of the weekend.
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.DISCUSSION...
Upper level ridge centered over the Central Great Lakes will continue to hold over the next couple days. 12z DTX sounding indicated a 500 MB height of 591 DAM, near record high for mid September per SPC climatology page. Morning fog, enhanced by light easterly flow off Lake Huron, is the only the noteworthy weather during the next couple days, as warm daytime temperatures push into the 80s. 12z DTX sounding indicated a similar profile to yesterday, and thus no surprise max temps are/or will be back into the lower 80s. 850 MB temps still looking to be aoa 13 C tomorrow, but then even slightly warmer for Wednesday and especially Thursday, supporting mid 80s for Wednesday and upper 80s for Thursday.
Elevated surface dew pts this afternoon into the 55-60 degree range will set the stage for fog once again, and will continue to favor areas of fog north of M-59 and patchy fog south.
The upper-level ridge will weaken to end the work week, with its axis positioning more toward the Western Great Lakes. A weak cold front will drop south through the Central Great Lakes Thursday night, but is expected to come through dry with little to no upper level support. Strong high pressure (1030+ mb) builds into northern Ontario Friday and into Quebec on Saturday. This will lead to a substantial east-southeast pressure gradient, which will likely keep daytime temps a bit cooler, especially with an increase in mid to high clouds for Saturday.
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.MARINE...
A ridge of high pressure will continue to bring an extended period of dry weather and lighter winds to the Great Lakes through the week. Some localized higher wind speeds nearing 15 to 20 knots will again be possible through the Saginaw Bay into the evening given the favorable northeast fetch. Otherwise, the next chance for more active weather will enter this weekend as a low pressure system nears the region.
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.PREV DISCUSSION... Issued at 147 PM EDT Mon Sep 15 2025
AVIATION...
Little change in the weather pattern the last 24 hours so another afternoon with sct diurnal cu which again should mix out this evening. We`ll again be watching for fog development tonight as radiational cooling and light moisture flux off the lakes with easterly flow continue over the area as the last two mornings. We`ll go IFR for MBS and FNT where it was lower vsby this morning, and watch trends for the other sites tonight.
For DTW/D21 Convection... No thunderstorms through the early week period.
THRESHOLD PROBABILITIES...
* Low for ceiling at or below 200 ft, or visibility below 1/2 SM early in the morning.
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.DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. &&
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DISCUSSION...SF MARINE.......AM AVIATION.....DRK
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NWS DTX Office Area Forecast Discussion