790
FXUS63 KDTX 162247
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
647 PM EDT Tue Jul 16 2024

.KEY MESSAGES...

* A slow moving cold front keeps scattered showers and non-severe
  thunderstorms in the forecast into this evening mainly for areas
  along and north of I-69. A few afternoon showers also possible on
  Wednesday afternoon as a cooler airmass settles into the area.

* High pressure brings cooler and less humid weather into the region
  for the late week period.

&&

.AVIATION...

The coverage of convection will decrease quickly after 00Z with the
loss in daytime heating. A weak cold front will continue its
southward progression across Se Mi this evening, forecast to exit
southeast of metro Detroit after 02Z. The advection of a drier low
level airmass tonight will limit any nighttime low clouds or fog
development. An upper level trough will move across Se Mi late
Wednesday afternoon. This will be the next chance for scattered
convection.

For DTW/D21 Convection...Convection chances will wane with the loss
in daytime heating. Any lingering convection across the metro
airspace this evening will be isolated.

DTW THRESHOLD PROBABILITIES...

* Low in thunderstorms this evening and again Wednesday afternoon.

&&

.PREV DISCUSSION...
Issued at 309 PM EDT Tue Jul 16 2024

DISCUSSION...

Scattered showers with some thunderstorms will traverse the region
this afternoon into this evening in advance of a cold front which
will drop south through the area into tonight. With deep shear in
the 30-35 knot range and modest instability (1000-1500 J/kg) within
a band immediately in advance of the front, a few strong storms are
not out of the question with locally gusty wind and/or small hail. A
majority of this activity will focus along and north of the I-69
corridor in the late afternoon to mid evening time frame with the
loss of daytime heating resulting in a steady diminishing trend
after 00z or so.

Additional scattered showers and perhaps an isolated thunderstorm or
two will be possible again Wednesday afternoon as main upper level
trough axis driving this front through the area shifts through the
Great Lakes. This activity will be enhanced during the peak heating
period from mid afternoon into early evening as colder mid level
temperature pools shifts overhead and leads to steepening lapse
rates.

Thereafter, a much quieter and pleasant period sets up as high
pressure builds into the area in the wake of this trough. This
period will extend from Thursday on through the weekend and more or
less into early next week. Daytime high temperatures will settle
back into the 70s Wednesday/Thursday and then edge back into the
upper 70s/lower 80s this weekend. Meanwhile, low temperatures in the
lower/mid 50s will be common late in the week with some moderation
back into the upper 50s to around 60 this weekend into early next
week.

MARINE...

A cold front is currently analyzed SW-NE between Saginaw Bay and
Georgian Bay, contributing to scattered showers and thunderstorms
along and immediately ahead of it. This front drifts southeastward
through the evening, effectively veering winds from SW to NW in its
wake. Widespread wind and wave potential holds below headline
criteria, although a stronger thunderstorm could produce gusts up to
35 knots. By Wednesday, surface high pressure begins to fill in
although influence of the upper level trough results in isolated
showers and storms in the afternoon. Quiet and dry marine conditions
are then expected from Thursday into the weekend as high pressure
becomes more established overhead.

&&

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

$$

AVIATION.....SC
DISCUSSION...DG
MARINE.......MV


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