Novi, Michigan 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

439
FXUS63 KDTX 301753
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
153 PM EDT Sun Mar 30 2025

.KEY MESSAGES...

* Potential for severe weather exists between 6 and 10 pm this
  evening. There is an Enhanced Risk (3/5) of severe thunderstorms
  south of a line from Saginaw to Cass City, with a Slight Risk
  (2/5) north of this line. Damaging winds, large hail, heavy
  rainfall, and an isolated tornado are all possible.

* High temperatures mostly in the 40s for Monday into Tuesday before
  the next round of warmer weather with showers and thunderstorms
  returns Wednesday.

&&

.AVIATION...

With fog/drizzle finally started to depart southeast Michigan this
afternoon and SSW winds increasing in speed, ceilings will gradually
lift into the MVFR range. These SSW winds have started to increase
across the area, especially across terminals that are south of the
stalled frontal boundary draped across Mid-Michigan and the Thumb
Region. Continue to expect SSW winds to gust upwards of 20-25 knots
this afternoon. The above mentioned stalled frontal boundary is
currently sitting in the vicinity of MBS, with is still being
impacted by 200 ft ceilings and 1/2 SM vsbys. As the surface low
lifts northeast across the state later this afternoon and evening,
this will eventually help veer winds with northeast winds becoming
easterly, then southeast, and eventually southwesterly by tonight.
As these winds veer and the stalled front lifts north, ceilings
should also slowly improve into the MVFR range by later this
evening.

Heavy rain and thunderstorms are expected to move through the area
as the low tracks through this evening. All terminals will likely
see thunderstorm activity, as the broken line of storms move
through. These storms look to impact terminals mainly between 22Z
and 03Z, with the main hazard being damaging winds. After convection
clears southeast Michigan, a cold front moves through and brings
additional stratus and wind shifts overnight and into Monday morning.

For DTW/D21 Convection...IFR stratus is expected to lift into the
MVFR range this afternoon as south/southwest winds increase. These
south/southwest winds will usher in better low-level moisture to
help fuel a broken line of storms this evening, which is expected to
move west to east across the D21 airspace. Timing looks to remain
close to the previously mentioned window, with convection moving in
from the west around/shortly after 22Z and exiting to the east of
the terminal/D21 airspace by 02/03Z. Damaging winds are the main
concern with this broken line of convection, and may pose a threat
for winds up to 60 mph as it moves through. All other severe weather
hazards are possible, but the damaging wind threat is of greatest
concern. A cold front follows the passage of convection late tonight
and into Monday morning. Winds veer and become WSW late tonight and
eventually NW on Monday morning. Until we get the drier, post
frontal air mass to move in on Monday, MVFR ceilings likely remain
in place overnight tonight.

.DTW THRESHOLD PROBABILITIES...

* High in ceilings aob 5000 feet today.

* Low in ceilings aob 200 feet today.

* Moderate to high in thunderstorms this evening.

&&

.PREV DISCUSSION...
Issued at 1027 AM EDT Sun Mar 30 2025

UPDATE...

14z surface analysis showing a warm frontal boundary still bisecting
the local area, remaining the catalyst for ongoing low cloud
development/maintenance and pockets of light showers. Gradual
northward migration of this boundary to commence with time through
the latter half the day, responding to the northeast ejection of the
associated surface low over eastern Iowa as strong height falls
spill into the midwest. Inbound pre-cold frontal warm sector
highlighted by a lower 60s dewpoint and recovery of temperature into
the 65 to 70 degree range by early this evening. Despite cloud cover
concerns to limit insolation potential, the advective process
affords respectible destabilization with latest model guidance still
projecting a peak in MLCAPE of 1-1.5 kj/kg from this profile.
Background low level and deep layer wind profile more than
supportive for organized convection with associated wind/hail
threats, while low level flow may remain backed just enough with
some curvature evident in the hodograph to maintain a tornado risk
assuming sufficient 0-3 km CAPE exists and lower LCL`s hold.
Forecast will continue to outline a 6 to 10 pm window for a higher
svr probability, noting some variation yet in exact timing as the hi
res solution space works to resolve pace of the frontal boundary and
associated convective initation/downstream propagation.

PREV DISCUSSION...
Issued at 418 AM EDT Sun Mar 30 2025

DISCUSSION...

Stalled frontal boundary remains draped across southeast Michigan
around the M-59 corridor maintaining the sharp north to south
temperature gradient. Observations show NE winds and mid 30s across
the Thumb/Saginaw Valley and S-SE winds and mid/upper 50s across
Detroit and southern Michigan border. Increasing southwest winds from
a 35-40 knot jet at 850 mb has brought elevated moisture with ties
to the Gulf into Michigan which is supporting the early morning
showers. Limited instability within the theta-e ridge should keep any
lighting potential at bay through the morning.

The stalled frontal boundary is forecast to lift northward into the
Saginaw Valley throughout the morning in response to the upstream
low pressure system that lifts northeast across the Midwest and
directly over north/central Lower Michigan this evening. A dry slot
will accompany the northward expanding warm sector this morning
resulting in limited precipitation chances after 11 am this morning
into the early/mid afternoon. Forecast remains focused on the
potential for severe weather later this afternoon and evening.
Models continue to show decent instability characterized by MLCAPEs
of 500-1000 J/kg building across the CWA by 4 pm as dewpoints
approach or achieve 60 degrees. If breaks in the clouds occur,
slightly greater instability will be achievable. Deep layer shear
will increase in the southeast quadrant of this system with 50 to 70
knot of low to mid level flow resulting in mean 0-6 km bulk shear
values of 30-40 knots. Shear is largely unidirectional/parallel to
the advancing cold front. This favors a more quasi-linear storm
mode, which is largely what hi-res models depict. This makes damaging
winds the main hazard. Storm-Relative hodographs do point towards
some low level curvature. Thus, an isolated tornado risk exists if
any embedded supercell structures or any discrete cells can exhibit a
more eastward storm motion. This would be especially true towards
the surface warm front if it is lingering around the Saginaw
Valley/northern Thumb and enough instability can get shoved that far
north. The 00Z RAOB from last night shows Precipitable Water to
around 1.25 inches, which is in the 90th to 98th climatological
percentile, supporting a locally heavy rainfall threat as well.
Large hail appears to be a secondary risk, but remains possible given
the relatively low freezing levels. Main timing of severe weather
has trended towards 6 pm to 11 pm with a Slight Risk still in place
for most of southeast Michigan.

The low pressure system will then track into Ontario with the strong
cold front sweeping through southeast Michigan tonight with dry air
quickly driving through Michigan. This will help precipitation come
to an end before there is a much chance for any lingering showers
late tonight/early tomorrow morning. Saginaw Valley and Thumb would
stand the best chance to see a few snowflakes if they do occur. Dry
conditions then expected for Monday and Tuesday. Daytime highs
return to the average for this time of year. Daytime highs mostly in
the 40s Monday and Tuesday with parts of the Thumb holding in the
30s. Coldest night of the week will be Monday night into Tuesday
morning with widespread lows down into the mid 20s.

The next low pressure system is set to impact the Midwest Tuesday
night and Wednesday. Expect temperatures to warm back into the 60s
with resultant warm and moist advection into Michigan. A plume of
Gulf moisture will again support a high likelihood of rain and
thunderstorms with the potential for heavy rainfall and possibly some
severe thunderstorms on Wednesday.

MARINE...

Lingering stalled warm frontal boundary is gradually forced back
northward starting early this morning and continues through the
majority of the day as a final, stronger low pressure center lifts
across the western Great Lakes. Winds shift to southerly for all but
northern Lake Huron as a result though gusts remain modest, around
or below 20kts. NE gusts over northern Lake Huron likely are
stronger, around 25-30kts, this morning before weakening by
afternoon as the low center approaches. Scattered thunderstorms are
possible this afternoon though greatest window for storms arrives in
the evening in advance of the attendant cold front. Numerous showers
and scattered t-storms are likely during the evening with some of
these storms being strong to severe- greatest threats are wind gusts
over 34kts and lightning with secondary, lower chance, threats being
hail and an isolated tornadic waterspout (mainly over the southern
Great Lakes). Surface low tracks directly over Lake Huron early
Sunday night ushering in colder northwest flow for Monday. Low
rapidly pushes into eastern Canada resulting in a weakening gradient
over the central Great Lakes which is expected to keep NW gusts
generally below 30kts. High pressure then builds over the region for
Tuesday bringing drier conditions and lighter winds.

HYDROLOGY...

A low pressure system will move in from the Midwest this afternoon
ushering in additional Gulf moisture. This environment is supportive
of heavier showers and increased coverage of thunderstorms.
Additional rainfall totals for today and tonight will be from a
quarter inch to a half inch on average with the majority falling
between 2 pm today and midnight tonight. Locally higher totals to an
inch will be possible with more organized thunderstorms. Rainfall
with the system late this afternoon and evening should be rather
progressive and only results in minor ponding of water in prone
areas along with rises in area creeks and streams. Higher impact
flooding is not likely at this time.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory from 8 AM Monday to 4 PM EDT Tuesday for
     LHZ421-441.

     Small Craft Advisory from 2 PM Monday to 4 PM EDT Tuesday for
     LHZ442-443.

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

$$

AVIATION.....JA
UPDATE.......MR
DISCUSSION...AA
MARINE.......KDK
HYDROLOGY....AA

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