Detroit, Michigan 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

389
FXUS63 KDTX 090436
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1236 AM EDT Wed Jul 9 2025

.KEY MESSAGES...

- Increasing chances for some showers and thunderstorms through this
  morning.

- Shower and thunderstorm potential and coverage increases this
  afternoon and evening. The strongest storms will be capable of
  producing wind gust around 45-55 mph. Highly localized flooding
  remains possible.

- Dry and warmer conditions return Thursday and Friday.

&&

.AVIATION...

A warm front lifts across the area sparking scattered showers and
possible thunderstorms. Scattered showers and possible thunderstorms
will last through the morning until around 11-12Z and focused from
FNT south to the southern metro terminals. Will still see
predominately VFR skies through tonight, but occasional MVFR
conditions will be possible with any activity that passes over
terminals. It`s possible showers linger after 11-12Z, but the
greater chances for more showers and thunderstorms is expected early
this afternoon associated with the cold front. Have maintained
PROB30 groups for this potential. VFR conditions follow thunderstorm
chances this evening into tonight.

For DTW/D21 Convection... There will be a low chance for
thunderstorms with shower activity through the morning hours.
Greater thunderstorm threat comes by around 16Z and through the
afternoon. Isolated severe weather will be possible.

THRESHOLD PROBABILITIES...

* Low for thunderstorms through this morning and again this
  afternoon.

&&

.PREV DISCUSSION...
Issued at 338 PM EDT Tue Jul 8 2025

DISCUSSION...

Tranquil conditions persist through the afternoon and evening with
seasonal temperatures. Elevated instability increases overnight as a
plume of theta-e rich air spreads into the region, with MUCAPE
values gradually increasing. While low-level WAA remains limited,
low-amplitude mid-level troughing pivots over the Great Lakes and
coupled with subtle convergence within the theta-e plume, will bring
increasing chances for elevated showers and thunderstorms late
tonight through tomorrow morning. By tomorrow afternoon and evening,
showers and thunderstorms will turn surface based as instability
rises aoa 1000 j/kg, fueled by diurnal heating. Some better forcing
will be found along a cold front that will pivot through the Tri-
Cities, Thumb and Flint region through the afternoon and early
evening hours. Additional weak convergence along lake boundary and
intrusion of southwest flow near the border will also be potential
areas for shower and thunderstorm development through the day.
Scattered to numerous showers with embedded storm development is
expected given the above.

Shear values are modest with 1-6km values of 20 knots, bringing the
potential for organized convection of isolated to multicellular
variety. The main threats will be stronger gust potential of 45-55
mph and small hail. Slow storm motions will bring the chance for
highly localized flooding potential. Please see the hydrology
section for additional details.  The moisture-rich low-levels will
likely be an inhibiting factor for any stronger mentions of gusts
reaching severe criteria. Instability wanes while the front clears
late tomorrow night, ending all precipitation chances.

Upper-level confluence will reinforce high pressure across the state
Thursday with its influence extending into Friday as high pressure
washes out across New England and the western Atlantic. This will
bring dry conditions through the end of the week with seasonal
temperatures. The next chance for showers and thunderstorms will
enter in the Saturday-Sunday timeframe. An upper-level disturbance
will come onshore across northern California into the Four Corners
before shearing out across the Midwest and Great Lakes. An upper-
level trough will trail the wave over the northern Plains, with this
prefrontal trough/cold front combination bringing the chance for
showers and thunderstorms. There still remains questions on phasing
of the aforementioned features, but the boost in warm air advection
ahead of any troughing feature does bring the chance for some
slightly above normal temperatures by Saturday, potentially
challenging the 90s through the Metro region.

MARINE...

Light and variable winds remain in place this afternoon and evening
as diffuse surface pressure field lingers over the central Great
Lakes a bit longer. A weak surface low/trough drifts across northern
Lower Michigan tonight and out over Lake Huron Wednesday while
gentle winds organize out of the SE. This draws more humid and
increasingly unstable air into the region while the governing upper
low tracks across eastern Ontario into western Quebec. The
combination of forcing and instability ensure periodic thunderstorms
Wednesday afternoon and evening, with later rounds tied to the
passage of the system`s cold front. Ambient dynamics are rather weak
which should keep prevailing conditions below Small Craft Advisory
criteria, but locally higher winds/waves are possible with some
stronger storms that might develop. Shortwave ridging slides east
Thursday allowing surface high pressure to build in from the Upper
Midwest which facilitates mainly dry conditions across the
waterways. A more robust low moves in late Friday into Saturday
with renewed potential for showers and storms.

HYDROLOGY...

Scattered to numerous showers and thunderstorms are forecast
tomorrow. Storms will be relatively disorganized, but with humid
conditions and slow storm movement, storms will be capable of
producing torrential downpours. Localized areas may receive over 1
inch per hour, with extremely localized rainfall totals ranging from
1-3+ inches, pending any thunderstorms training or repeated
thunderstorm activity. Highly localized flooding of urban areas,
small streams, and otherwise poorly drained areas will be possible.
The main threat for flooding will be between 1pm and 9pm.

&&

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

$$

AVIATION.....AA
DISCUSSION...AM
MARINE.......KGK
HYDROLOGY....AM


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