Expert Forecast Opinion

754
FXUS63 KDTX 272356
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
756 PM EDT Wed May 27 2026

.KEY MESSAGES...

- Low chance remains for isolated evening showers or
thunderstorms, south of a line from Howell to Grosse Isle.

- Temperatures return closer to late May normals Thursday through
the weekend, with the exception of a brief warm-up Friday.

- After today, the only chance for rain will be late Sunday into
Monday morning.

&&

.AVIATION...

VFR conditions are expected to prevail this evening into tomorrow
with mainly high clouds moving in from the northwest. There is a
boundary stalled out along the southern Michigan border as a mid
level wave moves overhead leading to a weak shower response moving
across the terminal corridor from northwest to southeast. Very brief
shower observation at MBS at press time, so will maintain the PROB30
for remainder of the TAF sites through 01-02Z. Not expecting any
thunderstorms with this activity based on latest radar trends.
Showers may bring a brief reduction in ceilings, but it should still
remain VFR and above 5kft. Strengthening northeasterly flow mid-
morning tomorrow brings a brief window for scattered shallow cu.
Mixing will then bring mostly clear skies with NE gusts reaching
around 20 knots.

D21/DTW Convection...Latest radar trends preclude any mention of
thunderstorm this evening with the weak area of showers moving down
the I-75 corridor.

.DTW THRESHOLD PROBABILITIES...

* Very low for an isolated thunderstorm mainly through 02Z.

&&

.PREV DISCUSSION...
Issued at 320 PM EDT Wed May 27 2026

DISCUSSION...

A weak backdoor cold front slows from southern Lower Michigan into
the northern Ohio Valley. Several competing synoptic factors will
affect the development of conditional isolated afternoon showers and
thunderstorms for portions of Southeast Michigan. A positively
tilted shortwave trough embedded within northern stream flow
descends on the region, overcoming the blocking influence of an
anticyclone anchored over the central Atlantic. Poor model consensus
exists regarding instability through the rest of the afternoon, as
large dewpoint depressions inhibit destabilization. The highest
potential for convective initiation will be located in the vicinity
of the frontal slope where dewpoints of 60F are still possible. Tall
and skinny CAPE profiles with an inverted-V shape below 5 kft (DCAPE
in excess of 700 J/kg) lead to a low-end wind threat should
sufficiently deep updrafts arise. The lack of moisture and shear
limit the intensity and coverage of storms, should any arise. Based
on the latest frontal positioning, any convection that materializes
should be confined to points near and south of a line from Howell to
Grosse Ile. Anomalous high temperatures repeat today, in the lower
80s outside the Lake Huron shadow, or about 10F above normal. Loss
of daylight quickly diminishes any thundershower activity, followed
by post-frontal cooling and further drying overnight.

Lower Michigan will reside within the proximity of the inflection
point of the northern stream jet Thursday morning with gradual
mid/upper height rises building throughout the day. A ridge axis
marked by 500 mb heights of 585+ dam centers between Manitoba and
Florida, remaining nearly stationary into the weekend, while
troughing lingers over northeastern NOAM. Encroachment of warmer air
aids in lifting/mixing 850 mb temperatures into the teens (Celsius)
Friday, before the thermal gradient drifts back toward the west.
Highs in the 70s are then expected to continue through at least the
first half of next week as the pattern remains locked-in. Near-zero
PoPs Thursday through Sunday with high pressure parked squarely over
the state. Some semblance of an opportunity for rain late Sunday
into Monday as a zonally oriented trough axis descends due-south
from Hudson Bay, triggering nocturnal ascent amidst weak Theta-e
advection from the Upper Midwest. Medium-range
deterministic/ensemble/ML/AL models very in generating QPF with this
setup.

MARINE...

As high pressure expands from northern Ontario into Lake Superior
tonight, there will be an increase in the north-norhteast winds
across the eastern lakes. Wind gusts will reach or exceed 20 knots
in the warmer nearshore waters. This will boost wave heights,
leading to hazardous conditions to small craft. Winds and waves will
decrease late Thursday into Thursday night as the surface high
gradually sinks southward into the Ohio Valley by Friday. A weak
surface cold front will then push across Lake Huron Friday night, in
advance of another strong high pressure system. This may result in
another period of hazardous small craft conditions in the
nearshores.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory from 6 AM to 2 PM EDT Thursday for LHZ421-422-
441.

Small Craft Advisory from 6 AM to 6 PM EDT Thursday for LHZ442-443.

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

$$

AVIATION.....AA
DISCUSSION...KGK
MARINE.......SC


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