888
FXUS63 KDTX 300833
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
433 AM EDT Sun Aug 30 2026

.KEY MESSAGES...

- Widespread showers and thunderstorms this morning through tomorrow
  morning. Additional chances Monday afternoon into Tuesday.

- Severe storms are not expected, but there is potential for a swath
  of locally heavy rainfall focused across the Thumb that may bring
  localized flooding concerns this morning through Monday morning.

- Slight warmer temperatures and increased humidity during the early
  to mid week with unsettled weather pattern remaining.

&&

.AVIATION...

An influx of moisture along the nose of a low level jet located
closer to Lake Michigan has elicited very healthy coverage of rain
showers across western Michigan, which will work into Southeast
Michigan through the remaining morning hours. As a result, all
locations now have prevailing rain showers for this morning.
Intensity of rain showers will be light to moderate given limited
instability in place, however, an isolated rumble of thunder cannot
be ruled out. Some brief visibility restrictions to mvfr will be
possible under the stronger rain showers, but overall ceiling heights
are expected to remain vfr. Shower and thunderstorm chances continue
through the afternoon and evening, with most favorable location for
any thunderstorms setting up across KMBS to KFNT, aligned with where
an elevated warm front intensifies.

D21/DTW Convection...Scattered to numerous rain showers likely
through the morning and early afternoon. There will be a low chance
for an isolated thunderstorm but overall confidence in thunderstorms
remains low.

.DTW THRESHOLD PROBABILITIES...

* Low in thunderstorms this morning and afternoon.

&&

.PREV DISCUSSION...
Issued at 317 AM EDT Sun Aug 30 2026

DISCUSSION...

Brief period of increasing subsidence will mark this early morning
period as high based scattered shower activity from decaying MCS
continues to decrease in coverage. Attention quickly turns to an
expanding area of precipitation this morning that will continue
through today. Widespread/numerous showers and scattered
thunderstorms will be forced along a warm frontal zone and theta-e
ridge with additional support from the low level jet, though
strongest LLJ winds hold to the west. The warm front sets up over
Lower Michigan this morning then lifts northward towards the I-69
corridor later today focusing the higher coverage of showers with
time across northern Lower Michigan and southeast through the Thumb.
The overall airmass will be quite moist as dewpoints climb into the
60s and PWATS values increase to 1.75 inches or greater across
southeast Michigan while approaching 2 inches over the Thumb.
Overall severe threat will be very limited with the lack of surface
instability and mean MUCAPE values generally around 500 J/kg or
less, peaking later this afternoon and evening. Main concern will be
for repeated rounds of showers and thunderstorms that could bring
locally heavy rainfall. After a brief period of lower QPF potential
later this evening, an additional uptick in convective potential
occurs late this evening through Monday morning as a cold front then
drops into northern lower Michigan support a corridor of more focused
forcing. While shear will remain favorable, severe potential again
looks limited given the weaker instability. Locally heavy rainfall
will continue to be the main concern.

Model consensus puts the axis of heavier precipitation focused along
and north of a line from Midland to Port Huron. Average total
rainfall amounts to around an inch are forecast in this axis
starting this morning (12Z) to early Monday afternoon (18Z).
A localized swath of 2 to near 4 inches of total rainfall will be
possible across parts of the Thumb, which is highlighted well in the
HREF 24-hr QPF ensemble localized probability-matched mean. Amounts
to half an inch are forecast down to roughly the M-59 corridor and a
quarter inch or less south of M-59 down to the southern border.

Southeast Michigan will reside on the northern end of a ridge during
the early to mid-week period. Slight increase in heat and humidity
will arrive with the persistent west-southwest low to mid level
flow. Embedded shortwaves within this flow around the ridge will
continue to offer chances of precipitation into mid-week. Given the
pattern and potential for continued chances of rainfall and
increased cloud cover, current NBM forecast temperatures are
probably on the high side mid-week if that pans out. Michigan will
remain in a corridor of higher PWATs, which keep the potential for
localized heavy rainfall as a concern during this stretch and daily
organized convective chances will depend on the degree of
instability that is able to develop each day.

MARINE...

We continue the transition out of high pressure today with as a
developing low pressure system over the northern Plains begins to
impact the area. The leading warm front has lifted into southern
Michigan and will keep overcast skies and rain chances through the
day. In addition, a cold front will be drifting southward toward the
northern Great Lakes adding to the forcing which will drive
precipitation chances. Winds will largely be from the south today
with max gusts around 20 knots. Winds turn more southeasterly on
Monday while remaining mostly below 20 knots before turning westerly
on Tuesday.

&&

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

$$

AVIATION.....AM
DISCUSSION...AA
MARINE.......DRK


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at www.weather.gov/detroit.