Expert Forecast Opinion

259
FXUS63 KDTX 150952
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
552 AM EDT Mon Sep 15 2025

.KEY MESSAGES...

- Extended stretch of dry conditions with highs well above average
this week.

&&

.AVIATION...

Fog development has been much patchier late tonight compared to
yesterday with most of the terminals still sitting in lower VFR
vsbys. Densest fog has been confined over Midland with MBS residing
on its fringe. This IFR/LIFR fog likely creeps in over the terminal
early this morning but should begin to start burning off by the
start of the new TAF period. High pressure still holds across the
region maintaining lighter winds and SCT VFR diurnal cu by
afternoon.

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.

&&

.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.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

$$

AVIATION.....KDK
DISCUSSION...MR
MARINE.......MR


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