Novi, Michigan 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

654
FXUS63 KDTX 222104
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
404 PM EST Mon Dec 22 2025

.KEY MESSAGES...

- There is a low chance for freezing drizzle tonight into Tuesday
morning before temperatures climb above freezing by daybreak. Only
trace amounts of ice will be possible.

- Above normal temperatures through the mid and late week period.

- An area of low pressure is forecasted to track near the southern
Michigan border late Thursday night and Friday. With temperatures
near the critical freezing mark, the potential exists for a wintry
mix, including rain, snow and freezing rain impacting the Friday
morning commute.

&&

.DISCUSSION...

Deep dry air in the lowest 8.0 kft agl has made light snow activity
intermittent and scattered in nature thus far today. Models remain
consistent in a relatively dry period 21-03z this evening as a
fairly hearty wedge of dry air between 925-750mb lifts northward
through Southeast Michigan. This secondary drying of the low levels
and resultant lull in any precipitation or radar returns will then be
followed by the advection of a low-midevel tongue of moisture on the
nose/eastern periphery of low level jet axis. Quite the complicated
and disjointed moisture evolution today because as the secondary
moist surge arrives this evening, plan view of moisture on
isentropic moisture shows moisture stripping out aloft. With
forecast soundings supporting saturation in the lowest 7.0-8.0 kft
agl well below the -10C isotherm, expecting most areas to observe
light precipitation in the form of drizzle or freezing drizzle
overnight. The big question remains whether or not surface
temperatures will be at the freezing mark. Current dewpoints in the
20s suggests that temperatures will have an opportunity to drop a
few degrees this evening below freezing before the drizzle activity
begins. Conditional to this cooling and staving off any of the warm
air to the southwest, there is the potential for a period of light
freezing drizzle overnight. Zonal orientation of the low level jet
axis should allow for temperatures and dewpoints to rebound fairly
quickly late, around daybreak. The models suggest the slowest
thermal rebound will be the northern Thumb. Impacts are expected to
be limited to pockets or isolated slippery spots on roadways.

The North American Ensemble Forecast System supports a record
breaking ridge across the central United States that will expand
into the doorstep of the central Great Lakes for the middle of the
week. An impressive feature with 582 dam heights through Kansas and
into the Tennessee River Valley, (at the maximum per the CFSR
datasets). This all supports a warm/balmy period through Christmas
day.

For Tuesday, any dry dewpoint front/values will be slow to
release through the cwa as there is a lack of any definitive cold
front. Warm daytime highs in the lower to middle 40s with fairly low
mixing depths tempering west winds in the 15 to 25 mph range. Given
the slow exit of the surface moisture, may need to watch for some
lighter fog activity from the terrain southward to the Ohio border
Tuesday evening. Low confidence in anything impactful. A stronger
absolute vorticity maximum tracking north of Lake Huron will support
a flattening of the thermal field and allow some cooler air to
backdoor into Michigan for Wednesday. Dry air and subsidence in the
2.0 to 8.0 kft agl layer will support precipitation free conditions.
Highs Wednesday will be some 5 to 10 degrees cooler, ranging in the
middle to upper 30s. Bulk of the forecast data from this vantage
point suggests nothing more than an inconsequential moisture
increase late Wednesday night as an entrance region to a jet streak
and very ragged shortwave energy passes through the Ohio Valley.
A lot of question how far northward up the frontal slope moisture
will be able to overrun. Could be looking at another period of some
light mist/fine drizzle with surface temperatures at or just above
freezing. Current offered guidance on PoPs seems a little high, but
did leave the late Day3 values as is. 850mb temperatures of +3 to +6
C will support high temperatures Christmas Day in the upper 30s to
lower 40s some 5 degrees below normal.

Confidence is increasing for widespread precipitation across
Southeast Michigan late Thursday night and Friday as yet another warm
advection surge pushes through the Great Lakes. Well defined jet
exit region dynamics off of a coherent, well organized jet streak is
expected to bring fresh dynamical support for ascent to the state.
WPC cluster analysis does suggest a higher predictability solution
at Day 3 with relatively low variance amongst the 24 hour averaged
500 heights. Both eofs suggest no timing or magnitude anomalies in
vicinity of Southeast Michigan. Latest control run of ECMWF has
shown up in agreement with the earlier GFS solutions depicting
overrunning precipitation for Southeast Michigan late Thursday and
Friday. The big note here is the latest control run of the ECMWF has
a precipitation footprint from Kentucky northward through Lake
Superior. Will need some data inside of the hires window but depths
of both the near surface cold layer and the warm air aloft will
matter heavily in microphysics and the precipitation type forecast.
Plenty of algorithms support freezing rain with QPF amounts of 0.25
to 0.30 inch. Friday morning is a period to monitor.

&&

.MARINE...

Wind direction to back from southwest to southeast tonight in
response to the passage of a low pressure system which will traverse
west to east across southern Ontario. This will bring some localized
higher gust potential around 25 knots through southern Lake Huron
given the favorable fetch.  Passage of the low into Quebec will push
a warm front across the Great Lakes, bringing widespread but light
rain/snow mix.

Continued passage of the low will then bring a glancing area of cold
air across northern Lake Huron tomorrow evening into early Wednesday
morning. This will boost shallow over lake instability and improve
mixing depths, bringing increasing confidence to see gust to gales
within this time frame. A Gale Watch has been issued for north and
north-central Lake Huron. Additionally, wave heights will build over
the outer Saginaw Bay through the tip of the Thumb, where Small
Craft Advisories will likely be needed. High pressure then quickly
builds in through the day Wednesday, rapidly diminishing stronger
gust potential through the later morning hours.

&&

.PREV DISCUSSION...
Issued at 1213 PM EST Mon Dec 22 2025

AVIATION...

A couple bands of elevated warm frontal forcing have supported some
very brief light snow reports. This forcing will move east of the
airspace very early in the forecast period. The mid-cloud canopy
will persist - with some breaks in the late daylight window. An
aggressive push of low-level moisture will occur during the late
evening hours. Pockets of very light rain or drizzle will develop as
the near surface layer begins saturating. At the onset with the dry
air still in place, some of the liquid has some freezing on contact
potential for a few hours leading up to midnight. Ceilings at the
same time will be rapidly lowering into MVFR and toward IFR and
light fog development is also likely. The low-level moisture will
hang around until the mid-late morning hours, when dry air is pulled
in from the northwest as high pressure builds back into the region.

For DTW...after a few flurries in the first hour with limited
lowering of the cloud deck, ceilings will lift dramatically for the
balance of the afternoon. Ceilings will then progressively lower
this evening - with an eventual chance for liquid precipitation
after 02z. The initial droplets may freeze on contact - since the
surface wet bulb temp will be a few degrees below freezing. As the
dewpoints rise after midnight, the freezing potential vanishes.
Ceilings will continue to lower toward daybreak, with batches of
drizzle and light fog. Conditions will improve toward midday on
Tuesday.

DTW THRESHOLD PROBABILITIES...

* High in ceilings aob 5000 feet after midnight tonight.

* Low to moderate for a couple hour period late this evening for
  light freezing rain.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Gale Watch from Tuesday afternoon through Tuesday evening for
     LHZ361-362.

Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

$$

DISCUSSION...CB
MARINE.......AM
AVIATION.....Mann


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