818
FXUS63 KDTX 030402
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1202 AM EDT Thu Jul 3 2025

.KEY MESSAGES...

- Mainly dry conditions and warming temperatures into the Weekend,
  with max temperatures back into the lower 90s on Saturday.

- Chance (40-50%) for showers and thunderstorms in the Sunday
  afternoon - Sunday night time period.

&&

.AVIATION...

A stray shower or thunderstorm remainS possible during the late
night based on activity still percolating upstream toward the surface
cold front, although coverage this far south has low predictability
through the morning. Larger scale conditions support VFR for SE MI
under and high debris clouds from the evening storms while the cold
front remains on schedule to settle southward. It is expected to
reach the MBS area during the morning and then stall/wash out toward
the Ohio border in the afternoon. Broken VFR ceiling near 5000 ft is
likely in and near the frontal zone with a renewed chance of storms
focused closer to the DTW corridor into Thursday evening.

For DTW/D21 Convection... A chance of storms returns Thursday
afternoon.

THRESHOLD PROBABILITIES...

* Moderate for ceiling 5000 ft or less in the afternoon.

* Low for thunderstorms in the afternoon into Thursday evening.

&&

.PREV DISCUSSION...
Issued at 300 PM EDT Wed Jul 2 2025

DISCUSSION...

Thoughts have not changed much from the morning update. Temperatures
in the mid 80s with dew pts in the lower 60s/around 60 this
afternoon (as of 18z) have lead to an extensive Cu field with MLcapes
near 1000 J/kg north of M-59. A few showers have popped up as well.
0-6 KM bulk shear is weak (under 25 knots), but slightly better wind
fields (30- 35 kts) this evening as 500 MB shortwave trough axis/cold
front arrives. No big issues with the marginal/isolated severe
threat, particularly over the Thumb region, which will be closer to
the mid level cold pool over the northern Great Lakes. Isolated
precip loaded wind gusts of 50-60 mph with a secondary hazard of
marginal hail up to 1 inch in diameter due to low wet bulb zero
heights.

The cold front looks to wash out tonight as it reaches the southern
Michigan border by 12z Thursday. Upper level northwest confluent
flow during the day will result in general subsidence and allow for
a mainly dry day. However, with inverted surface trough in the mid
section of southern Lower Michigan and some moisture pooling,
MLcapes building up around 1500 J/kg draw concern for isolated
strong-marginally severe storms with some leftover decent mid level
flow and a high degree of Dcape. However, mid lapse rates are weak
and very dry, drawing in question if updrafts will be strong enough
to overcome dry air entrainment. Slight chance pops included for late
afternoon across the southern/southwest sections of the CWA.

Upper level ridge over Central North America will slowly roll over
to the east through the first half of the Weekend. This will support
very warm to hot temperatures and mainly dry conditions through
Saturday. With 850 MB temps reaching up to 20 C on Saturday with the
moderate low level southwest flow, should have no problem with maxes
reaching into the lower 90s, with heat indices reaching into the mid
90s to possibly upper 90s.

Upper level flow along the northern Conus then trends to pseudo
zonal to end the weekend, with a shortwave and cold front bringing
the best chance of showers and thundestorms Sunday afternoon/evening.
Shrinking but good moisture plume associated with this front, as PW
values reach near 2 inches. Euro ensembles suggesting 40-50 percent
chance of a tenth of an inch or greater of rainfall. Sprawling high
pressure in place early next week, allowing for quiet weather and
near normal temperatures.

MARINE...

Scattered shower and thunderstorm chances linger through the evening
with best potential focused over the southern half of Lake Huron. An
isolated strong storm capable of 34+ kt winds and hail can`t be
ruled out. A weak cold front settles south of the region by late
tonight resulting in generally light northwesterly flow to start
Thursday. Weak surface high pressure follows, setting up directly
over Lake Huron by late Thursday maintaining lighter winds as well
as more variability in direction. An isolated shower/t-storm is
possible on the periphery of the high towards Lake Erie Thursday
afternoon however the vast majority of the region stays dry. Hotter,
more humid air returns this weekend as a warm front lifts through
the central Great Lakes late Friday-Saturday. Moderate SW winds flow
the front with gusts peaking around 20kts, particularly over the
central portions of Lake Huron. A cold front sagging into the Great
Lakes then brings storm chances latter half of Sunday through
Monday.

&&

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

$$

AVIATION.....BT
DISCUSSION...SF
MARINE.......KDK


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