158
FXUS63 KDTX 260731
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
331 AM EDT Thu Jun 26 2025

.KEY MESSAGES...

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

- There is a Marginal Risk of severe weather as storms may produce
damaging down burst winds. Localized flooding will also be possible
due to very moist airmass and saturated soils from recent storms
this week.

- 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
today through the weekend with heat indices up into the mid to upper
90s at times.

&&

.DISCUSSION...

We remain on the northwestern edge of the large ridge across much of
the SE conus today. The ridge is slowly weakening though still
remains around 590 dam. This ridge continues to steer a very moist
airmass up through the Plains and across lower MI with PWATs still
hovering around 1.75 to 2+ inches which will carry through the end
of the week. Surface dewpoints took a hit across much of the area
when the cold front dropped through Tuesday, but remain around 70
across the far south and 60s for the rest of the area. This has lead
to showers/storms being very efficient rain makers the last couple
days with the uncapped, high CAPE, low shear environment with a few
areas developing localized flooding. This will remain a main concern
through the end of the week until Friday when a stronger system
passes through the Great Lakes and pushes the moisture south. We
remain in a Marginal Risk of Excessive Rainfall for both days to end
the week.

Will be hard pressed to remove chances of showers/storms during any
period through Friday as the persistent frontal boundary will
continue to meander about the region with the slightest ripple in
along the elevated front producing showers. The main difference
between today/Friday vs the previous two days of convection though
will be that we`ll have some more notable synoptic waves tracking
through the region through this main moisture axis bringing a couple
periods of more targeted pops.

The first wave is ongoing at press time, traveling through northern
MI and pulling the 850mb front back up through the area with
convection already firing along it over GRR. The surface front will
also get drawn northward this morning building north and east with
time allowing more unstable air (MUCAPE >2000 J/kg) back into a
larger portion of the CWA. Will keep chance pops at least through
the day with another period of scattered to numerous storms expected
with peak heating and the main instability gradient in the vicinity
of I-69. Localized flood risk with these storms along with wind
threat from precip loaded downbursts. Some small hail will be
possible with some storms. The second wave will again track through
northern MI Friday pulling the warm frontal surface farther north
through the whole CWA early in the morning with a chance of
convection firing along it as we get a bit more of the 850mb low
level jet (25-30 knots) over the area helping provide a bit better
forcing locally. We`ll be warm sectored most of the day allowing for
another unstable day with CAPE >2000 J/kg, but the warm sector will
provide a little cap to deal with. The cold front will get pulled
into the area in the afternoon/evening bringing another round of
more widespread convection.

Temperatures will make a run at 90 for our southern portion of the
CWA the next two days and when combined with the low-mid 70
dewpoints may result in heat indices in the mid to upper 90s,
possible touching 100 for a short period. With the expected cloud
cover and scattered convection, we will hold off on any heat
advisories at this time.

&&

.MARINE...

Warm front has lifted north into northern Lower Michigan this
morning, leading to stronger (25+ knots) easterly winds over the
northern Lake Huron. A wave of low pressure coming out of the Midwest
will trigger numerous strong to possibly severe thunderstorms.
Another round of strong storms on Friday before the low exits east.
Light northwest flow follows the low for Friday night into Saturday
before winds become light southerly for the second half of the
weekend with mainly dry conditions.

&&

.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. Showers and storms area ongoing this 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.

&&

.PREV DISCUSSION...
Issued at 1157 PM EDT Wed Jun 25 2025

AVIATION...

A persistent region of low stratus with intermittent scattered to
broken coverage will continue to mark conditions into the overnight
period. Observational trends suggest primarily a lower VFR ceiling
height, but brief MVFR will be plausible at times. A warm front will
lift across the area Thursday morning. Some potential exists for a
low coverage of showers and thunderstorms to develop with this
frontal passage. An increasingly unstable environment will emerge
for the afternoon hours as moisture increases once again. This will
lead to scattered to numerous showers and thunderstorms during the
afternoon and evening.

For DTW/D21 Convection...Potential exists for thunderstorms to again
impact DTW during the afternoon hours.

 THRESHOLD PROBABILITIES...

* Medium for thunderstorms Thursday afternoon and evening.

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


&&

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

$$

DISCUSSION...DRK
MARINE.......SF
HYDROLOGY....DRK
AVIATION.....MR


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