Pontiac, Michigan 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

802
FXUS63 KDTX 252317
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
717 PM EDT Wed Jun 25 2025

.KEY MESSAGES...

- Scattered to numerous showers and thunderstorms this afternoon and
evening, along and south of the I-96/I-94 corridors.

- Scattered thunderstorms late tonight grazing the Tri Cities and
northern Thumb into Thursday morning.

- Scattered to numerous thunderstorms again Thursday afternoon as
warm and humid air builds back into Lower Michigan.

- A chance of thunderstorms continues Friday into the weekend as an
active pattern holds across the Great Lakes.

- High temperatures increase back to the upper 80s to 90 degrees
Thursday through the weekend.

&&

.AVIATION...

Area remains north of a frontal boundary overnight, allowing briefly
drier air to arrive under prevailing light northeast flow. This
process remains slow, affording a lingering window for isolated
showers and thunderstorms to develop late this evening. Potential
remains too limited to highlight any one location at this stage.
Otherwise, thicker canopy of higher based cloud will exist at times
through the night, with a weak signal for some lower VFR or MVFR
cloud to possibly emerge late tonight. Southwest flow emerges
Thursday, drawing the stalled front back northward into the region.
This will lead to another round of scattered to numerous showers and
thunderstorms during the afternoon and evening.

For DTW/D21 Convection...Scattered to numerous thunderstorms will
develope Thursday afternoon

 THRESHOLD PROBABILITIES...

* Medium for thunderstorms Thursday afternoon and evening.

* Low in ceiling at or below 5000 feet tonight and Thursday.

&&

.PREV DISCUSSION...
Issued at 423 PM EDT Wed Jun 25 2025

DISCUSSION...

Temperature and moisture contrast remain sharp across the front up
against peak heating this afternoon helped by a substantial band of
clouds still in place after morning showers. This front remains the
weather highlight for this afternoon and tonight, and really all the
way through the late week period as a couple of larger waves of low
pressure track along it.

This afternoon, the surface front and weak wind shift settled to a
position near the I-96/I-94 corridors with showers/storms developing
along and south of the boundary into moderate instability. Mid
afternoon mesoanalysis indicates MLCAPE increasing to 1500 J/kg
following RAP/HRRR projections that briefly reach 2000 J/kg near the
Ohio border before fading this evening. A mostly uncapped convective
response produced a few respectable updrafts in the vicinity of the
front and Lake Erie lake breeze where backed low level flow helped
maximize an otherwise pedestrian wind profile. The mixed convective
mode in this scenario still favors a precip loaded downburst wind
gust with some small hail also possible within the narrow mid level
CAPE profile. What is also still notable is the moisture depth
projected to hold near 2 inch PW moving forward from the 12Z DTX
sounding that makes heavy rainfall and localized flooding an equal
if not primary hazard through the evening.

As ongoing convection fades this evening, attention turns to the low
pressure system across the upper Midwest to which the Ohio border
front is connected. Showers have been occurring all day in that
area, along and north of the surface low and warm front, with
thunderstorms along the trailing cold front, all boosted by stronger
and more organized larger scale forcing. It is upper jet dominated
today followed by an increasing component of DCVA from the 4 corners
mid level wave as it lifts into the Plains tonight and Thursday.
Continued surface low development then leads to a strengthening low
level jet late tonight that drives the convective response widely
supported by 25/12Z hi-res, regional, and global model runs. The
developing surface low also pulls the current stalled front slowly
back northward beginning late tonight, enough so that elevated/LLJ
driven convection becomes favored in the 850-700 mb theta-e gradient
moving into the northern Great Lakes. Some of this convection does
graze the Tri Cities and Thumb region toward sunrise into Thursday
morning as the warm front moves into central Lower Mi which sets the
stage for a new round of surface based storms in the afternoon. The
upper Midwest wave of low pressure ripples along the warm front to
help touch things off and also pulls the front southward behind it
for an additional afternoon and evening focus. Convective clusters
then move through the warm sector across SE Mi with at least a
Marginal risk of severe intensity well into the evening. Yet another
wave of low pressure resets the pattern Thursday night and Friday in
very similar fashion to close out an active late week period.

MARINE...

High pressure over western Quebec has pushed frontal boundary south
of the Michigan border, resulting in light easterly winds over the
Central Great Lakes through tonight. Still enough instability around
Lake St. Clair and Lake Erie to trigger scattered showers and
thunderstorms, which may be strong to severe. Another wave of low
pressure looks to be coming out of the Midwest tomorrow, lifting the
frontal boundary north as a warm front. Easterly winds will pick up
significantly north of the front, but stronger winds (reaching 25
knots) should be confined to northern Lake Huron. The front and low
will result in numerous showers and strong thunderstorms returning,
which looks to be continuing into Friday. Light northwest flow
follows the low for Friday night into Saturday before winds become
light southerly for the second half of the weekend.

HYDROLOGY...

A front wavering north and south across Lower Mi will be focus for
showers and thunderstorms today through Friday, and possibly through
the weekend. For this afternoon and tonight, the area along and
south of the I-96/I-94 corridor has greater coverage and heavy rain
potential. Showers and storms ongoing over the upper Midwest also
graze the Tri Cities and northern Thumb late tonight and Thursday
morning as the front moves back northward. The front becomes the
focus for yet another round of storms in the afternoon which spread
across the area in warm and humid air returning to the region. All
of this occurs in a deep/high moisture environment that promotes
heavy rainfall rates that could lead to localized flooding. Typical
urban, small stream, and flood prone areas are most at risk but also
any location that experiences repeated rounds of showers and
thunderstorms, which could happen anywhere across SE Michigan during
the mid to late week period.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

$$

AVIATION.....MR
DISCUSSION...BT
MARINE.......SF
HYDROLOGY....BT


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