407
FXUS63 KDTX 111747
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
147 PM EDT Wed Jun 11 2025

.KEY MESSAGES...

- Breezier and much warmer today with highs well into the 80s and
gusts in excess of 30mph.

- Cooler with periods of showers and storms Thursday through the
weekend.

&&

.AVIATION...

Low pressure tracks across northern lower MI this afternoon, with
winds veering to the northwest in response. A disturbance aloft is
allowing gusty winds of 25 to 30 knots to mix to the surface, which
will wane this evening. As the low departs, cold advection sinks
southward and establishes a deformation axis overhead. This causes
light winds (aob 5 knots) to veer to the east between roughly 05z
and 08z, settling out of the east for the remainder of the TAF
period. A narrow band of cloud cover and shower activity emerges as
moisture advects into the frontal zone, but looks to stay between
Cadillac and Flint Thursday morning.

For DTW/D21 Convection...No thunderstorms expected through the
period.

THRESHOLD PROBABILITIES...

* None.

&&

.PREV DISCUSSION...
Issued at 335 AM EDT Wed Jun 11 2025

DISCUSSION...

Height rises have begun to expand over SE MI overnight as persistent
upper troughing has finally dislodged into eastern Canada. Airmass
that had been confined to the High Plains is rapidly advected into
southern lower MI in response rising 850mb temps from 8-10C this
morning to 14-16C by evening. While a piece of Gulf moisture
accompanies this airmass pushing surface dewpoints into the upper
50s/low 60s, magnitude of elevated warm advection as well as active
subsidence generates a respectable dry layer between 850-700mb
effectively capping any potential convection. Sunnier skies (albeit
still with some Canadian wildfire smoke) further aids in pushing
temps firmly above average towards the mid 80s with upper 80s
possible around Metro Detroit (average highs are upper 70s). High
res model soundings all are in good agree with diurnal mixing
heights reaching near 5kft this afternoon with winds at that level
ranging from 30-35kts in the south to 35-40kts across the north.
Expect another breezy day, likely more so than Tuesday, as west-
southwest gusts will be able to reach 25-30mph for areas south of I-
69 and 30-35mph for areas north (a few gusts pushing near 40mph not
out of the question towards the Saginaw Valley/western Thumb).

Low pressure sliding across the Straits draws its attendant surface
cold front into the central Great Lakes early tonight into Thursday.
While the overall late week period still carries a fair degree of
uncertainty, 00Z model suite has come into better agreement late
tonight-Thursday timeframe. Cold front is slow to progress south
holding across south-central lower MI with the frontal orientation
largely parallel to mean low level flow resulting in very weak
forced ascent along the boundary. Even with moisture pooling in
advance of the front, lack of ascent likely leads to an initial dry
fropa until a PV anomaly ejecting out of the northern Plains arrives
after 06Z Thursday. This wave generates a narrower band of scattered
showers along the elevated portion of the frontal boundary focused
over areas north of I-69- some thunder possible as a ribbon of 300-
600J/kg of elevated CAPE is fed into it. PV anomaly pushes east of
the area by afternoon tapering off showers. There is signal amongst
a subset of the solution space (like the 00Z HRRR/GFS) to try and
initiate scattered convection near the IN/OH/MI border along the
surface frontal boundary/instability gradient in the evening. That
said, even in these outcomes overall coverage into far southern SE
MI is limited.

Another shortwave ejecting out of the Rockies reaches the upper
Mississippi early Friday which partially lifts the stalled front
back north over during the day. Currently that looks to reach
between I-69 and M-46 leading to the bulk of showers/thunderstorms
being confined over the northernmost portions of the CWA up through
northern lower MI. How much rain develops over the southern portions
of the CWA is highly dependent on the speed of a southern Plains
closed mid-level low lifting towards the Ohio Valley/Great Lakes.
Faster solutions like the NAM bring showers into the rest of the
area by late day Friday whereas slower solutions like the ECMWF hold
it off until Friday night/daytime Saturday. This now phased mid-
level trough then slowly drifts toward the Southeast and mid-
Atlantic over the course of Saturday offering the potential for
surface high pressure to build over lower MI Sunday bringing a dry
second half of the weekend.

MARINE...

A warm front and associated strong wind field aloft will expand
across the Great Lakes today which will bring elevated wind speeds
and gust potential during daylight hours. The warm air aloft will
bring stable over lake conditions which will significantly stunt any
efficient mixing of these stronger winds aloft over the open water,
however with west-southwest flow, the immediate nearshore zones
should be exposed to the better well mixed over-land environment.
given some modest degree of horizontal momentum flux, have opted to
issue a Small Craft Advisory for the nearshore zones outside of
western Lake Erie. The location most favorable to elevated wind and
gust potential will be the Saginaw Bay given the favorable southwest
fetch. Otherwise, winds should quickly drop off after sunset with
light winds continuing into tomorrow as a weak pressure gradient
holds.

Showers and thunderstorm chances turn likely Friday into Saturday as
a frontal boundary pivots across the Great Lakes, specifically
across Lake Huron. Some prolonged rain chances will be possible
pending the final positioning of the front.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory until 10 PM EDT this evening for LHZ421-422-
     441>443.

Lake St Clair...Small Craft Advisory until 10 PM EDT this evening for LCZ460.

Michigan waters of Lake Erie...None.
&&

$$

AVIATION.....MV
DISCUSSION...KDK
MARINE.......AM


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