028
FXUS63 KDTX 081905
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
305 PM EDT Mon Jun 8 2026

.KEY MESSAGES...

- Showers and thunderstorms tonight and Tuesday will pose a locally heavy
rainfall threat. The potential exists for isolated damaging wind gusts with any
thunderstorm activity Tuesday afternoon and evening.

- Heat and humidity will build over Southeast Michigan for Wednesday and
Thursday. Afternoon temperatures are expected to reach the low 90s with heat
indices potentially climbing into the upper 90s. A Heat Advisory may eventually
be needed.

- Thunderstorms will be possible Wednesday and Thursday. The most likely
timeframe for organized severe thunderstorms may be late Thursday as a cold
front approaches the area.

- Not as warm and much less humid Friday and next weekend.

&&

.DISCUSSION...

Deep column high pressure will build out of the eastern Great Lakes
towards the Eastern Seaboard tonight. In response, gradient flow
will steadily veer to the south by Tuesday. The main narrative over
the next 24 to 36 hours will be rich thetae advection into the
forecast area that will cause PWATS to climb toward 2.00 inches.
Surface dewpoints on Tuesday are expected to be in the low 70s.
Scattered, high based shower chances begin this evening with lead
spoke of absolute vorticity lifting into the area. Modest cooling
above 12.0 kft agl should result in weak elevated instability that
could support a shower or rumble of thunder. Static stability in the
lowest 8.0 kft agl will limit any strong thunderstorm threat today.

Warmer and much more humid for Tuesday. Old, convectively augmented
low pressure circulation will drift slowly eastward from southern
Wisconsin through northern Lower Michigan and the northern Lake
Huron basin. Southeast Michigan will be situated solidly within the
moisture transport axis for the first half of the day before a weak
cold front feature pushes across between 20-04z. Projected CAPE
values Tuesday afternoon are expected peak in the 1750-2250 J/kg
range with 0-6km bulk shear 25 knots. Low shear limits convective
organization and convective vigor potential but high PWATS suggests
wet microbursts and water loading possibly leading to an isolated
damaging wind gust threat between 19-04z time window. A bigger
threat may be isolated flooding potential with heavy downpours. The
latest SPC Day 2 Outlook has Southeast Michigan designated as
General Thunderstorm.

A longwave ridge will expand in wavelength while centering over the
central Great Lakes Wednesday and into at least the first part of
Thursday. The associated geopotential thickness increase will result
in another uptick in surface temperatures reaching 90 degrees or
more for Wednesday and Thursday with heat indices well into the 90s
and potentially making a run at 100 degrees. Heat headlines may be
needed. 800-600mb lapse rates are forecasted to be steep enough to
result in SBCAPE reaching 3000 J/kg. From a dynamics perspective
model signal supports larger scale subsidence and capping with the
ridge parked overhead and episodic anticyclonic vorticity advection
timed out for both midday periods Wednesday and Thursday. The low
confidence portion of the forecast hinges on the subsequent tracking
of any upstream MCS tracking towards Lower Michigan. The important
note for Wednesday is 0-6km bulk shear values at 20 knots or less
for the entire period bringing question to whether or not convection
will be organized if it does make a run at Southeast Michigan. The
latest Swody2 has a Marginal risk designation merely brushing up
again Southeast Michigan. The period of most concern for strong to
severe thunderstorms may be Thursday evening and Thursday night as
the upper level trough advances towards the state. Models support
stronger wind field aloft and kinematics finally arriving late with
850mb winds climbing above 50 knots. The latest Day4 Outlook for SPC
has Southeast Michigan designated as 15% for severe thunderstorms.
More seasonable weather conditions look likely for Friday and the
upcoming weekend as a cold front sweeps out the humidity.

&&

.MARINE...

High pressure over New England migrates to the Mid-Atlantic this
evening, maintaining southeast wind on the order of 10 kt into
tonight. Weak low pressure tracks into southern Lake Michigan on
Tuesday before passing across Lake Huron Tuesday night. This brings
in a humid air mass with scattered to numerous showers and
thunderstorms during this period. Winds will carry a degree of
variability as the low tracks through, but remain around 10 kt
outside of any localized higher gusts within storms. A warm and
unstable air mass will take residence Wednesday and Thursday,
bringing additional chances for showers and thunderstorms. Flow will
be predominantly out of the west and southwest with potential for
gusts upwards of 20 kt at times.

&&

.PREV DISCUSSION...
Issued at 200 PM EDT Mon Jun 8 2026

AVIATION...

Column moistening is underway this afternoon as flow organizes out
of the south (above 5 kft AGL), responding to an inbound shortwave
drifting across Wisconsin, toward Lake Michigan. Lots of dry air
still exists, delaying the time until elevated showers are able to
precipitate and lift into the terminals this evening/overnight ahead
of an elevated warm frontal boundary. Instability will struggle to
materialize at the start, favoring initial thunderless convective
showers. Models disagree as to when moisture and mid-level cooling
will suffice for convection to develop more broadly, and with
stronger updrafts to support thunder. TEMPO-ed in an initial window
for -TSRA late tonight into the early hours on Tuesday (09-13Z) when
conditions appear more ripe. Low confidence in the coverage of
thunder with this initial round. A lull in activity will be possible
mid-morning Tuesday before the boundary layer matures heading into
the afternoon hours. This favors initiation of the next round of
scattered thunderstorms after 17Z. In terms of cig/vsby concerns,
ceilings fill in and lower to MVFR with time tonight. Should
thunderstorms cross a terminal, expect brief IFR drops in
visibilities.

D21/DTW Convection...There is a low chance for thunderstorms late
tonight into early Tuesday morning. Low confidence in the first wave
of possible convection reaching DTW, or at least while being capable
of producing thunder. TEMPO-ed in -TSRA from 09-13Z. Better coverage
of thunder arises through the Tuesday afternoon diurnal cycle, thus
a PROB30 for convection was added after 17Z Tuesday.

DTW THRESHOLD PROBABILITIES...

* Low for ceilings at or below 5000 feet this evening, then
  high overnight and Tuesday.

* Low to medium for thunderstorms 09Z through 13Z Tuesday, then
  medium after 17Z Tuesday.


&&

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

$$

DISCUSSION...CB
MARINE.......TF
AVIATION.....KGK


You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.