Updated:
27-Oct-2025 12:45pm
NWS Forecast Discussion
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FXUS63 KDTX 270834
AFDDTX
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
434 AM EDT Mon Oct 27 2025
.KEY MESSAGES...
- Becoming more seasonable and dry through the first half of the
week.
- Rain chances increase Wednesday night and Thursday as temperatures
trend below normal to close out the workweek.
&&
.AVIATION...
Narrow line of clouds (high MVFR) over western Lake Erie will
continued to be monitored, as a northward drift remains in play this
morning toward YIP/DTW. Confidence remains low, especially with
respect to BKN ceilings. Otherwise, strong surface high pressure
holds over Eastern Canada, maintaining clear-mostly clear skies and
low level easterly winds. Increased mixing depths during the
afternoon may yield a wind gust up to 20 knots.
For DTW/D21 Convection...No thunderstorm activity this TAF period.
DTW THRESHOLD PROBABILITIES...
* Low for cig aob 5000 feet this morning.
&&
.PREV DISCUSSION...
Issued at 359 AM EDT Mon Oct 27 2025
DISCUSSION...
A ridge axis extending across the Great Lakes will maintain dry and
mostly cloud-free conditions for the majority of Southeast Michigan
today. Once again, a climatologically cool start to the morning as
several rural areas are currently reporting sub-freezing
temperatures. Largely uninhibited diurnal insolation, coupled with a
slight increase in 850 mb temperatures, should send readings back
into the 50s for the midday hours. One noticeable difference today
compared to yesterday will be gustier winds, as peak afternoon
speeds could exceed 20 mph once stronger 925 mb flow drifts north of
the Ohio Valley. Constricted easterly gradient wind subsequently
resides near the Michigan/Ohio border. Also expect a higher cloud
fraction for portions of the southern four counties given the
favorable fetch along the long axis of Lake Erie. A bit milder
tonight with a few clouds around, so most areas should stay above
freezing.
The forecast area remains situated between 1035 mb surface high
pressure centered over the mid-section of Quebec, and a deepening
surface low west of the Mississippi. This configuration is
attributed to an increasingly ageostrophic jet streak racing into
the southern Plains, which will eventually impact Southeast
Michigan. However, Tuesday looks to be another benign day for
Southeast Michigan amidst a brief period of split-flow. Sub-
saturated easterly flow lingers, although daytime gustiness should
increase with favorable positioning of a low-level jetlet. Some
uncertainty exists regarding high temperatures Tuesday due to
conflicting guidance on thermal advection (a proportional mix of
positive and negative solutions).
Growing model consensus in the robust upstream shortwave trough
interfacing with a retrograding VortMax extending from The
Northeast. This then leads to rapid enhancement of the primary low
late Tuesday night into Wednesday. Deterministic and ensemble
solutions are better aligned in a longer residence time over The
Southeast before ejecting due north across the Virginias on
Thursday. This lends confidence in keeping the system`s
precipitation shield just south of Michigan during the midweek
period. Automated NBM guidance is slow in making this adjustment,
therefore outgoing PoPs are a bit aggressive for Wednesday. The
first chance for more meaningful rainfall arrives on Thursday. As of
now, the western extent of such rain remains a question which
implies some parts of the CWA could see next to nothing given the
current trajectory of the system. Forecast adjustments are
forthcoming.
MARINE...
The central great lakes will remain positioned between high pressure
centered over Quebec and low pressure lifting across the midwest
during the early week period. This will maintain an extended period
of easterly flow during this time. Sustained winds of generally 10
to 20 knots, with intermittent gustiness to 25 knots at times. The
prevailing onshore flow will bring increasing wave action along the
nearshore waters. Small craft advisory conditions for elevated wave
heights expected starting Monday evening and likely lasting into
Wednesday. No rain is in the forecast through at least Tuesday.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory from 8 PM this evening to 4 PM EDT Wednesday
for LHZ421-441>443.
Lake St Clair...None.
Michigan waters of Lake Erie...Small Craft Advisory from 8 PM this evening to 4 PM EDT Tuesday for
LEZ444.
&&
$$
AVIATION.....SF
DISCUSSION...KGK
MARINE.......MR
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.