918
FXUS63 KDTX 070954
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
554 AM EDT Mon Jul 7 2025

.KEY MESSAGES...

- Some lingering showers possible near the Ohio border early today.
Otherwise, cooler and less humid conditions expected.

- Dry and seasonable conditions Tuesday.

- Shower and storm potential returns mid-late week with temperatures
trending above normal.

&&

.AVIATION...

A cold front marked by a northerly wind shift has passed across all
TAF sites this morning with widespread low stratus now in place
across the area. The front continues slowly advancing onward into
Ohio and Lake Erie through the day as high pressure builds across
the Great Lakes. The low ceilings are expected to linger through the
morning hours, likely fluctuating between MVFR and IFR, before
daytime heating promotes mixing to VFR for the afternoon. Prevailing
north wind continues into this evening before going very light
tonight. Lingering moisture from recent rainfall may allow for some
pockets of ground fog development overnight but low confidence
precludes a mention in the TAF for now. Otherwise VFR conditions
through tonight.

For DTW/D21 Convection...Thunderstorms are not forecast today into
tonight.

THRESHOLD PROBABILITIES...

* High for ceiling 5000 ft or less this morning, then low this
  afternoon.

&&

.PREV DISCUSSION...
Issued at 300 AM EDT Mon Jul 7 2025

DISCUSSION...

Slow moving cold frontal boundary still anchored across southern
lower Mi early this morning will vacate the region to the south
through the latter half of the morning. Meaningful post-frontal
advective process effectively establishing an extensive canopy of
low stratus as a sufficiently moist low level environment quickly
saturates. This cloud likely too hold into the early afternoon,
before a secondary southward push of drier air arrives coincident
with increasingly influential daytime mixing in prevailing north
flow. Any lingering shower potential prior to fropa near ths Ohio
border remains of limited coverage. Notably cooler and less humid for
the peak heating period, with sufficient stability to maintain dry
conditions. Onshore flow off lake Huron mutes the diurnal temperature
recovery more significantly across the thumb region, capping highs
in the low to mid 70s. Elsewhere, recovery in temperature toward the
upper 70s/lower 80s anticipated.

High pressure fixated over the northern great lakes will govern
conditions tonight and Tuesday. This ensures a dry and stable
profile holds this period. Despite existing low level easterly flow,
a high degree of insolation potential affords modest modification of
the resident airmass Tuesday. Late day readings peaking in the low
to mid 80s - or right around average.

Generally zonal mid level flow will give way to broad, lower
amplitude troughing during the latter half of the week. This
transition driven by an initial window of modest falls Tuesday night
and Wednesday as minor shortwave energy embedded within the flow
traverses the region. This will draw slightly greater moisture
content into the region starting Wednesday. Typical diurnal boundary
layer destablization with steeper lapse rates gaining greater depth
given slight mid level cooling under the suppressed mid level
height field. Plausible this environment effectively removes any
lingering capping concerns, affording some pockets of free convective
development. Otherwise, reliance on still ill-defined sources of
ascent, likely in the form of lake breeze/outflow interaction and/or
regions of greater differential heating and moisture convergence.
Forecast will continue to outline a generic chance mention targeting
the afternoon and evening hours. Limited wind magnitude within this
pattern precludes a more organized convective risk.

MARINE...

Any lingering showers and thunderstorms early today mainly around
western Lake Erie will exit by midday as drier air increases
influence. Otherwise, post-frontal northerly winds will exist today,
peaking around 20 knots over lake Huron. Dry conditions with
generally light wind and wave action expected tonight and Tuesday as
high pressure establishes control. Turning warmer and more humid
Wednesday and Thursday, offering a favorable underlying environment
for afternoon and evening shower and thunderstorm development. Winds
generally remain under 20 knots outside of any storms through this
period.

&&

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

$$

AVIATION.....TF
DISCUSSION...MR
MARINE.......MR


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