300
FXUS63 KDTX 301914
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
314 PM EDT Sun Jun 30 2024

.KEY MESSAGES...

- Cooler and less humid conditions continue into tomorrow as high
  pressure ensures a dry forecast.

- Warmer and more humid conditions arrive midweek, with increasing
  potential for showers and thunderstorms Tuesday night into Wednesday.

&&

.DISCUSSION...

The cold frontal passage earlier today has ushered in a cooler and
much drier airmass. Dewpoints have dropped considerably since
yesterday with mid/upper 40s dewpoints pushing down into central
Michigan. The cold advection has lead to around a 10C or greater drop
in 850 mb temperatures from last evening to this afternoon. The
cooler temperatures also brought with it a fair amount of lower
clouds earlier in the day, which will scatter out heading into the
evening as drier air takes hold. Northwest winds will veer slightly
more to the north this evening as gusts subside. Light winds,
clearing skies, and the lower dewpoints should allow for a decent
drop in temperatures tonight. Most locations should drop into the 40s
with urban areas of Detroit more than likely holding in the low/mid
50s.

Surface high pressure will slide over Michigan tomorrow bringing stable
weather conditions and ensuring a dry forecast to start the work
week. The mostly clear skies and lower humidity will make for a
pleasant Monday. Full insolation will help boost daytime high
temperatures into the mid 70s with the northeast to east flow
throughout the day keeping temperatures slightly cooler along the
lakeshores.

Warm advection ramps up with the passing ridge axis on Tuesday.
Deeper south to southwest flow will usher in greater moisture into
the region. Models pointing towards the greater moisture/theta-e axis
being directed toward western and northwest lower Michigan during
daytime period Tuesday. The Tri-Cities and northern Thumb will
reside on the eastern edges of this greater surge of theta-e and
where PWATs climb to 1.75 inches worthy of at least lower end PoPs
across the Tri-Cities into the northern Thumb. The lack of
instability and lift during the daytime will likely yield dry
conditions for most of southeast Michigan with mainly an increase in
clouds. Temperatures will respond to this warm advection and warm up
to mid/upper 70s with low 80s possible across the metro region and
southern Michigan border.

The greater moisture with PWATs upwards of 2.00 inches will slide
eastward Tuesday night into Wednesday ahead of greater high falls
and a weakening cold front. The weakening nature of the front and the
Tuesday overnight/Wednesday morning timing bring some uncertainty in
exact coverage of precipitation. The degree of moisture and at least
the presence of boundary will keep a chance for showers in the
forecast with greater details on timing and coverage being adjusted
with upcoming forecasts. There is greater confidence in temperatures
during the mid-week period as 850 mb temperatures climb to near or
achieve 20C bringing daytime highs for Wednesday into the mid/upper
80s. A trough diving through the northern plains and upper Midwest
will keep shower and thunderstorm chances in the forecast for the
late week period.

&&

.MARINE...

High pressure expands into the Great Lakes for the rest of today and
Monday, ensuring dry conditions to start the work week. Northwest
winds and onshore waves subside this evening, with Small Craft
Advisories on track to expire with the next update. The high
pressure center slides overhead Monday, shifting winds to the
southeast by afternoon in advance of the next period of unsettled
weather mid-week. Uptick in winds/waves begins late Tuesday
alongside increasing shower and thunderstorm chances, which will
precede a cold front late in the day Wednesday. Precipitation
chances are most likely across the north half of Lake Huron with
more scattered activity expected to the south.

&&

.PREV DISCUSSION...
Issued at 123 PM EDT Sun Jun 30 2024

AVIATION...

Steep low-level lapse rates under a much cooler air mass has allowed
expansive an expansive strato-cu deck to hold over most of SE MI,
with cloud bases ranging between 3-4 kft. A strong high pressure
system will advect in dry air and will settle over the Great Lakes
tomorrow. This combined with the loss of daytime heating tonight
will result in clear skies.

For DTW/D21 Convection...Thunderstorms are not expected during the
upcoming forecast.

DTW THRESHOLD PROBABILITIES...

*  High in ceilings aob 5kft through the afternoon. Low this
   evening.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement until 10 PM EDT this evening for MIZ049.

Lake Huron...Small Craft Advisory until 10 PM EDT this evening for LHZ421-441-
     442.

     Small Craft Advisory until 4 PM EDT this afternoon for LHZ422.

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

$$

DISCUSSION...AA
MARINE.......MV
AVIATION.....AM


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