749
FXUS63 KDTX 301723
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
123 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.

&&

.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.

&&

.PREV DISCUSSION...
Issued at 353 AM EDT Sun Jun 30 2024

DISCUSSION...

Mid level wave lifting across the northern great lakes early this
morning, affording modest height falls throughout the region with an
associated cold frontal passage ongoing locally. Effective
replacement of the existing moist airmass underway as low level flow
attains greater depth with time from a northerly trajectory. This
cooler/drier profile becomes entrenched to finish the weekend
period. Model consensus on projected highs lends confidence to a
rather muted overall diurnal temperature response by late June
standards. A diurnal boost to lapse rates beneath broad mid level
cylonic flow points to a more extensive stratocumulus field
developing, capping the heating potential somewhat and ultimately
parking temperatures in the upper 60s/lower 70s. A reasonable
radiational cooling environment governed by decreasing cloud
coverage and wind speed under building high pressure nets a low
temperature Monday morning near 10 degrees below average.

Confluent upper level northwest flow atop a 1025 mb surface high
ensures a stretch of deep layer stability within a very dry airmass,
affording benign weather to start the work week. Steady rise in the
geopotential height field as the weekend mid level trough
relinquishes control will bring an initial period of moderating
temperatures today. Full insolation potential offers an additional
boost, yielding pleasant conditions highs of mid 70s and low
humidity.

Pattern of warm air advection emerges Tuesday and Tuesday night as
southerly flow attains greater depth and strength within a broader
region of upper ridging. Shortwave energy cruising through the mean
flow offers focus for an initial period of moisture transport
upstream and corresponding convective expansion during this time.
Streamline trajectories suggest greater moisture advection will
primarily take aim across west/northwest lower Michigan throughout
the daylight period, although the eastward expanse of the elevated
moist plume lead edge could glance across the Saginaw valley. Higher
quality moisture will then accompany eastward expanding height falls
and the associated cold front boundary into the region overnight
Tuesday night and especially into Wednesday. Precipitation potential
will increase accordingly. Ill-defined forcing field overall at this
stage, with frontal timing/strength relative to the heating cycle
proving important for guiding the coverage and magnitude of any
convective response. 850 mb thermal ridge of +20c anchored locally
within the pre-frontal environment nets the warmest conditions of
the week.

MARINE...

High pressure moves in today and brings northwesterly flow of 20
knots or greater across parts of Lake Huron. Winds speeds and
directions will push wave heights above criteria for a Small Craft
Advisory to be issued for the nearshore zones of Lake Huron with the
exception of Inner Saginaw Bay. Small Craft Advisories will be in
effect from 7am to 10pm. There is also a high swim risk for Huron
County tomorrow, and a Beach Hazards statement is in effect from 8am
to 10pm tomorrow.

As the high pressure center moves overhead on Monday winds will calm
and dry conditions will prevail. Pressure gradient tightens once
again with the departure of the high on Tuesday leading to southerly
flow up to 20 knots. The next chances for showers and storms come
Tuesday evening as a low pressure system moves in.

&&

.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>443.

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

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

$$

AVIATION.....AM
DISCUSSION...MR
MARINE.......BC


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