Northeast, Michigan Weather Forecast Discussion

243
FXUS63 KDTX 010358
AFDDTX
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1158 PM EDT Tue Sep 30 2025
.KEY MESSAGES...
- No significant weather nor precipitation expected through the next
seven days.
- Above normal temperatures retreat to more seasonable readings mid-
week.
&&
.AVIATION...
Cooler but dry air originating from high pressure centered on James
Bay continues moving across Lake Huron and later from Lake Erie into
Lower Mi during the night. Assessment of cloud trends based on
evening observations indicate lake moisture flux is sufficient to
hold surface Td in the 50s inland toward the terminal corridor while
wind speed maintains 5+ knots. These observations and short term
forecast projections favor fog potential more limited to the usual
sheltered locations while monitoring for stratocu mainly in the MBS
area and DTW corridor. The latest model soundings suggest the
moisture a bit shallow for lake stratocu with the possible exception
of from western Lake Erie as potential cloud layer wind veers toward
the SE by sunrise. Improved observational evidence is needed before
adding any lower clouds in later updates. Otherwise, another dry
weather day is expected with a greater component of high clouds by
afternoon into Wednesday evening.
For DTW/D21 Convection... Thunderstorms will not occur through the
forecast period.
DTW THRESHOLD PROBABILITIES...
* None.
&&
.PREV DISCUSSION...
Issued at 325 PM EDT Tue Sep 30 2025
DISCUSSION...
A surface cold front, facilitated by the loss of daytime heating,
will push east to west off of Lake Huron this evening. The big
change with the front will be the lowering of surface dewpoints into
the 40s for the majority of Southeast Michigan. The exception will
be those areas immediately downwind of the Great Lakes where surface
dewpoints could be running 5 degrees or so higher. Did add some
patchy fog mention outside of the urban heat island but easterly
gradient wind will be more elevated than this morning. Expecting fog
to be localized. The strong mid-upper blocking ridge of 582-588 dam
will remain the primary influence throughout the week and first half
of the upcoming weekend. Forecast soundings show high static
stability between 1.0 and 9.0 kft agl for much of the week. An
extended run of dry weather is in store with 72hr NBM probabilities
for greater than 0.01 inch of rain through 12Z Saturday October 4
are approximated at 0%.
Daytime temperatures both Wednesday and Thursday will be at or
slightly above normal in the upper 60s to lower 70s. Daytime
temperatures will then rebound considerably Friday and into the
weekend at some of 10 to 15 degrees above normal. Current forecast
data support very high mixing depths and temperatures easily
climbing into the middle 80s.
MARINE...
High pressure drifts across James Bay this afternoon, supporting
northeast flow across the Great Lakes. The onshore flow and tight
gradient combine to support Small Craft Advisory conditions through
Wednesday morning, with gusts over 25 knots and waves over 5 feet.
Flow gradually veers through the rest of the week as the high
settles into New England, maintaining the extended stretch of dry
weather and affording quiet winds/waves through end of week.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement until 4 AM EDT Wednesday for MIZ048-054-055.
Beach Hazards Statement until 10 AM EDT Wednesday for MIZ049.
Lake Huron...Small Craft Advisory until 10 AM EDT Wednesday for LHZ421-441.
Small Craft Advisory until 4 AM EDT Wednesday for LHZ422-442-443.
Lake St Clair...None.
Michigan waters of Lake Erie...Small Craft Advisory until 10 AM EDT Wednesday for LEZ444.
&&
$$
AVIATION.....BT
DISCUSSION...CB
MARINE.......MV
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.

NWS DTX Office Area Forecast Discussion