814
FXUS63 KDTX 162018
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
318 PM EST Sun Nov 16 2025

.KEY MESSAGES...

- Colder and brisk today. Wind gusts in excess of 30 MPH at times.
Light scattered lake effect rain-snow showers persist in the
Thumb through the evening.

- There is a chance for rain and snow on Tuesday, mainly south of
the I-69 corridor. Some wintry mix is possible near the Ohio border
Tuesday morning.

&&

.DISCUSSION...

Ongoing light scattered lake effect rain-snow showers over the
northern portions of CWA continue through the late afternoon as
strong northwesterly flow maintains a moisture feed from Lake
Michigan. Some subtle veering of low level winds by 10-20deg to the
west this evening confines lingering lake effect activity to the
Thumb and northern Tri-Cities as upper Midwest surface high pressure
slowly builds into southern lower MI. Increasing subsidence under
said high Monday maintains drier conditions with remnant lake effect
banding holding to the east over Lake Huron/southern Ontario as well
as more abundant sun chances outside the Thumb. The slow expansion
of the high doesn`t allow the gradient to weaken until Monday
evening supporting another breezier day as gusts peak around 20-
25mph.

A mid-level shortwave ejects out of the central Rockies late Monday
eventually reaching the southern Great Lakes/Ohio Valley by Tuesday
morning. There still remains a good degree of variability in the 12Z
model suite wrt to the northern extent the associated precip shield
reaches with solutions like the GFS/Canadian advertising as far
north as the I-69 corridor whereas the NAM/NAM Nest struggle to get
further north than I-94. This lends to lower confidence in PoP
chances outside of the Ohio border areas with running forecast from
NBM maintaining broad brushed chances. However, confidence is high
that this precip shield will have a sharp northern cutoff due to
surface high pressure over the northern Great Lakes feeding cool,
dry air into southern lower MI. Lead f-gen band is progged to reach
southern SE MI around 12Z with light precip persisting through the
day. This arrival time leads to a sensitive forecast for p-type as
surface temps are forecast to be near or below freezing as lower
level warm air attempts to nudge north of the state line. If warmer
air can make sufficient inroads, there is potential for some
freezing rain-wintry mix over southern CWA Tuesday morning before
temps warm enough to transition towards rain. Should the more
northerly outcomes manifest, areas north of I-94 look to stay cold
enough to support snow at onset transitioning towards rain-snow or
rain-melting snow.

System peels away from the region Tuesday evening allowing northern
Great Lakes high pressure to fully expand across the state
overnight. This high maintains influence through early Thursday
morning favoring a seasonably cool but dry midweek. Active pattern
looks to return by late week as long range models highlight a pair
of northern/southern stream shortwaves sliding across the central
CONUS.

&&

.MARINE...

The central and eastern Great Lakes remain under influence of New
England low pressure and its expansive pressure gradient. This has
led to widespread observations of gale force gusts across the open
waters and Thumb nearshore zones last night and today. The northwest
flow regime has not been favorable for gales over Saginaw Bay, so
opted to replace the Gale Warning with a high-end Small Craft
Advisory. Otherwise, headlines remain unchanged. Gusts will begin to
dissipate late this evening as the low wraps into northern Quebec,
drawing its gradient east with high pressure quickly filling in
behind it. The more relaxed gradient allows winds to further subside
through Monday, with wave heights following suit. By Monday night,
the waterways should be headline-free as the high pressure center
takes full control. The next system tracks across the Ohio Valley
Tuesday, with the main impact being winter precipitation potential
south of Lake Huron. A second round of high pressure then returns
mid-week, flipping winds to the south.

&&

.PREV DISCUSSION...
Issued at 100 PM EST Sun Nov 16 2025

AVIATION...

Gusty northwest flow (300-320 degrees) remains in place across the
terminals this afternoon, drawing Lake Michigan moisture into the
low-levels. This has led to some lake-effect streamers spilling
downstream, resulting in periods of (melting) flurries. This
activity will continue in widely scattered fashion through the
remainder of the daylight hours with no impact on visibilities. The
combination of ceilometer and satellite data suggest variability in
ceiling development this afternoon and early evening, although low-
end VFR should be maintained during times of BKN stratocumulus,
based between 3.5 kft and 5 kft AGL. 25-30 knot gusts should taper
off shortly after sunset, once stability turns more neutral.
Gradient flow backs westerly overnight with with speeds holding near
10 knots into Monday with few clouds and no precipitation.

For DTW...Gusts to 30 knots with a few lake-effect flurries and VFR
conditions, then clearing out overnight with decreasing wind speeds.

DTW THRESHOLD PROBABILITIES...

* Low for ceiling 5000 feet this afternoon.

* Low for exceeding crosswind threshold from 310 degrees this
  afternoon and evening.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Gale Warning until 10 PM EST this evening for LHZ361>363-441-
     462>464.

     Small Craft Advisory until 4 PM EST Monday for LHZ421.

     Small Craft Advisory until 4 AM EST Monday for LHZ422-442-443.

Lake St Clair...Small Craft Advisory until 10 PM EST this evening for LCZ460.

Michigan waters of Lake Erie...Small Craft Advisory until 10 PM EST this evening for LEZ444.

&&

$$

DISCUSSION...KDK
MARINE.......MV
AVIATION.....KGK


You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.