592 FXUS63 KDTX 151747 AFDDTXArea Forecast Discussion National Weather Service Detroit/Pontiac MI 147 PM EDT Mon Sep 15 2025
.KEY MESSAGES...
- Extended stretch of dry conditions with highs well above average this week.
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.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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.PREV DISCUSSION... Issued at 357 AM EDT Mon Sep 15 2025
DISCUSSION...
High magnitude upper level high pressure system centered squarely over the great lakes during the early week period. This exists atop a sprawling surface anticyclone anchored across western Quebec that maintains a light east/northeast low level flow. Associated well above average warmth firmly entrenched locally. Little evidence of any meaningful thermal advection today and Tuesday, with expectation for a well mixed profile under full insolation to yield a virtual carbon copy of T/Td both Mon & Tue of that noted yesterday. Inherent stability residing throughout the column within this stagnant pattern ensures continued dry conditions. Conducive environment given the light onshore flow for some degree of nocturnal near surface moisture flux off the great lakes, maintaining potential each night for patchy to areas of fog development during the early morning hours.
Upper ridging maintains influence through the latter half of the week, as northern stream height falls associated with shortwave energy shearing across Hudson Bay simply glances across the northern great lakes. This maintains this extended stretch of benign weather. Temperatures edge upward slightly midweek, likely peaking Thursday in the mid/upper 80s as the core of the thermal ridge marked by 850 mb temps of mid teens eases overhead. A broad area of height falls settling across the plains will attempt to organize before lifting toward the great lakes sometime next weekend. Mixed signal yet across the model ensemble envelop in terms of defining the downstream pace and effective influence on conditions. Latest NBM guidance offers some introductory lower end precip chances for the weekend period, with temperatures easing back toward average.
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 this afternoon and 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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.DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. &&
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AVIATION.....DRK DISCUSSION...MR MARINE.......MR
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NWS DTX Office Area Forecast Discussion