632
FXUS63 KDTX 151048
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
548 AM EST Sat Nov 15 2025

.KEY MESSAGES...

- Warm today with highs climbing well above normal into the 60s.

- A cold front this evening brings rain chances late in the day and
a sharp drop in temperatures tonight.

- Breezy conditions of 30 to 40 mph are possible both today from
the southwest and Sunday from the northwest.

- Near normal temperatures expected through early next week.

&&

.AVIATION...

Ongoing low level moisture advection along a surface warm front
overhead has proven slow to develop low clouds. Current observations
suggest any semblance of MVFR based clouds is now occurring east of
the terminals. A secondary surge in low level moisture is however
going to advance into Se Mi around or shortly after 14Z, marked by
upstream sfc dewpoints in the upper 50s. There is a much stronger
signal among the latest model suite indicating this secondary
moisture push into the warm front will support a rapid
development/expansion of MVFR based clouds. Subtle boundary layer
growth and strong low level wind fields with 30 knots atop the mixed
layer will result in some slight lifting of cloud bases during the
afternoon. A cold frontal passage late this afternoon will result in
a veering of the winds to the west-northwest. Cold air advection
during the evening will lift cloud bases to VFR.

For DTW...Probabilities for sub 5000 foot clouds will be high by
late morning into the afternoon given the late morning moisture
advection. Winds will back to the west after 19Z, with a gradual
veering toward the west-northwest during the evening. Late cold air
advection will sustain low level mixing depths supportive of wind
gusts around 25 knots.

DTW THRESHOLD PROBABILITIES...

* High for ceiling 5000 feet or less today and this evening. Low
  overnight and Sunday morning.

* Low for exceeding crosswind threshold from 300 direction this
  afternoon and tonight.

&&

.PREV DISCUSSION...
Issued at 328 AM EST Sat Nov 15 2025

DISCUSSION...

Model suite staying fairly consistent with the overall setup and
forecast for the dynamic system that will track through the Great
Lakes today. Parent low remains well to the north over northern
Ontario while a secondary low is beginning to develop down the
occluded front over northern MN at this time. A strong 130 knot jet
entering the Pacific NW will surge through the base of the longwave
trough this afternoon stretching the strongest height falls
southward over the Great Lakes and in turn deepening the newly
developing surface low. This low is drawing a warm front northward
through SE MI which will pass north of the area by morning. Low
level jet will increase to around 40 knots as low as 900 mb per both
RAP and HRRR soundings which is below the warm nose capping
inversion centered around 750-800mb so we should be able to mix down
some decent winds in the warm sector today with gusts reaching 30-40
mph. Cold front looks to sweep east by 00Z this evening flipping
winds around to the NW which will remain gusty through the overnight
and into Sunday as a tight gradient and cold advection help fuel
deeper mixing. Overall wind field aloft will be in the 30-35 knot
range from 925-750mb which is almost the depth of the mixed layer
so expect another breezy day with gusts again potentially reaching
30-40mph.

The one trend in the guidance for this system today is drier. Though
the PWATs increase to around an inch, the soundings show a segmented
profile with a wealth of low level moisture and some elevated
moisture, but a notable dry layer from 5-10kft within the warm nose
which no models scour out. Will keep a slight chance pop for most
locations today as the prefrontal trough may squeeze out some light
showers and the cold front itself in the early evening tries to
offer enough low level convergence to touch off some showers,
especially up toward the Thumb. Passage of the cold front in the
evening will quickly dry out the column ending all precip chances
for the overnight. There is no good signal yet for lake effect on
Sunday to push far enough SE from the Lake Superior to northern Lake
MI connection to reach SE MI so will keep the forecast dry. Will be
much cooler Sunday as well with highs only in the low 40s after
rising much above normal today into the low to mid 60s.

Seasonal conditions will continue through the coming week with highs
hovering in the low to mid 40s, near normal for mid November as high
pressure streams into the region from central Canada. Confluent flow
aloft in a split flow pattern will help to prevent any thermal swing
in either direction for the time being. There is a chance for
showers on Tuesday as a shortwave races through Ohio with the
northern extent possibly reaching north into the area. Better
chances for precipitation look to arrive next Thursday/Friday as
both the GFS and ECMWF advertise a large low pressure system passing
over the Great Lakes.

MARINE...

The cold front tied to low pressure lifting into the Hudson Bay
reaches the Great Lakes this morning. In response, winds locally
organize out of the east-southeast and steadily veer southwest
through the rest of the morning. Strong warm advection within this
flow regime lessens overlake instability and subsequent mixing
potential keeping gusts around or below 25kts.

The secondary low center quickly pushes southeast across Manitoulin
Island and into southern Ontario Saturday afternoon driving the cold
front across the central Great Lakes. Colder air rapidly sinks south
out of northern Canada as the upper trough settles across the Great
Lakes. Strongest NW winds are expected to occur in this initial
surge of cold air Saturday evening/night aided by a locally enhanced
gradient from the low over southern Ontario. High probability (>70%)
to reach gales 35-40kt across the bulk of Lake Huron save for the
far southern waters during this timeframe. There is a chance (~40%)
at a few gusts creeping into the lower 40kts particularly over in
the northern portion of the lake given the favorable fetch. Gale
Warnings remain in effect for all open waters north of Port Sanilac
and the Port Austin nearshore waters as a result. Saginaw Bay had
been left out of these lead warnings due to stability concerns.
Latest GLERL water temps advertise significant cooling in the Bay
with waters sitting at 4-7C, some 5-8C cooler than the open lake
waters. This results in more neutral or only slightly unstable
thermal profiles as the lead edge of the Canadian airmass advances
south, relative to the solidly unstable profiles over the rest of
Lake Huron. While a few gusts to gale force are likely,
frequency/duration continues to look too marginal for a warning.

Northwest winds weaken slightly going into Sunday morning as the
secondary low pushes up the St Lawrence offering a few hour window
where gusts dip toward the lower 30kt range. However, any potential
lull will be short lived as a secondary cold front drops through the
region late morning-afternoon Sunday marking the arrival of the core
of the Canadian airmass. This fropa reinforces cold advection into
the area supporting another round of widespread gales (34-38kts) for
the latter half of Sunday. This includes the Saginaw Bay as air
temps now are firmly cold enough to support unstable thermal
profiles and more unimpeded mixing. Worth noting the wind field is
aloft in model sounds remains 5-10kts weaker compared to Saturday
night greatly reducing any potential for gusts to reach or exceed
40kts during this portion of the event. Small Craft Advisories also
remain up for all nearshore waters that aren`t gale warned. High
pressure begins to build in Sunday night into Monday allowing winds
to weaken below gales and eventually below 30kts.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Gale Warning from 5 PM this afternoon to 10 PM EST Sunday for
     LHZ361>363.

     Small Craft Advisory from 2 PM this afternoon to 9 AM EST Sunday
     for LHZ421-422.

     Gale Warning from 9 AM to 10 PM EST Sunday for LHZ421-422.

     Gale Warning from 8 PM this evening to 10 PM EST Sunday for LHZ441-
     462-463.

     Small Craft Advisory from 5 PM this afternoon to 4 AM EST Monday
     for LHZ442-443.

Lake St Clair...Small Craft Advisory from 7 PM this evening to 10 PM EST Sunday for
     LCZ460.

Michigan waters of Lake Erie...Small Craft Advisory from 7 PM this evening to 10 PM EST Sunday for
     LEZ444.

&&

$$

AVIATION.....SC
DISCUSSION...DRK
MARINE.......KDK


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