South Lyon, Michigan Weather Forecast Discussion

762
FXUS63 KDTX 110712
AFDDTX
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
312 AM EDT Thu Sep 11 2025
.KEY MESSAGES...
- Dry today and Friday with above normal high temperatures, but
  areas of fog appear likely tonight.
- Chance of showers and slight chance of thunderstorms Saturday.
- Warm and dry Sunday through Wednesday.
&&
.DISCUSSION...
The upper-level ridge axis over the Western Great Lakes will extend
into the Central Great Lakes this evening, with 500 MB heights
reaching 584 DAM and holding through Friday. This should ensure dry
conditions with a modest warming in the low levels each day as 850
MB temperatures are expected to reach around 12 C Thursday, and then
reach and slightly exceed 13 C on Friday. Thus, temperatures in
the low to mid-80s seem reasonable on Friday (assuming morning fog
burns off in a timely fashion).
A strong PV anomaly/upper level low is on track to move through
Hudson Bay on Friday and into Quebec on Saturday. Southeastern
Michigan will be on the western fringe of the large trough that will
sink south through New England and eastern Great Lakes on Saturday.
A tight baroclinic zone is setting up with compressional warming on
the lee side of the Rockies ejecting northeast from the Central
Plains. There is a chance for showers and possible thunderstorms on
Saturday as a shortwave moves out of the northern Rockies and tracks
through the region. However, the exact track, position, and amount
of instability and steepness of mid level lapse rates remain in
question. The NAM is one most aggressive solutions, with not a whole
lot of support from other solutions. NBM pops is still indicating
only a chance of precipitation.
The summer-like upper level ridge axis is still on track to move
overhead for Sunday and Monday. 500 MB heights are projected to reach
590 DAM (supported by Euro ensembles), and center of the ridge may
hold in place through mid week, leading to dry and warm conditions
Sunday-Wednesday.
&&
.MARINE...
High pressure drifts from Ontario to New England today and tomorrow,
ensuring dry and calm marine conditions to end the work week. Light
NE winds gradually veer to the SW by Friday as the high departs. SW
flow advects elevated portions of a warm front into the area Friday
afternoon, introducing low end shower chances Friday night into
Saturday although better rain chances stay over Lake Michigan. High
pressure then builds back into Ontario early next week, complemented
by ridging aloft, to continue the stretch of favorable marine
weather.
&&
.PREV DISCUSSION...
Issued at 1157 PM EDT Wed Sep 10 2025
AVIATION...
Mixed coverage of high clouds drift through the upper air pattern
above diffuse surface pressure across the Great Lakes. VFR is
maintained in an otherwise dry boundary layer over the region. Light
and variable to calm wind becomes NE at 10 knots or less as larger
scale high pressure builds from northern Ontario into Quebec during
the day into Thursday evening.
For DTW/D21 Convection... No thunderstorms during the late week
period.
THRESHOLD PROBABILITIES...
* None.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&
$$
DISCUSSION...SF
MARINE.......MV
AVIATION.....BT
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at www.weather.gov/detroit.

NWS DTX Office Area Forecast Discussion