220
FXUS63 KDTX 142336
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
636 PM EST Thu Nov 14 2024

.KEY MESSAGES...

- Scattered light shower chances linger through this evening as low
pressure gradually shifts to our east. Aside for a couple lake
effect showers in the Thumb, dry weather returns for the majority of
the area Friday.

- Slightly above average temperatures in the lower 50s Friday and
Saturday as high pressure becomes established.

- Much above normal temperatures arrive Sunday on the backside of
high pressure as highs reach into the upper 50s.

- Active pattern develops across the CONUS next week offering
multiple chances for rain locally, particularly the latter half of
the week.

&&

.AVIATION...

Very moist low level conditions entrenched tonight and Friday as a
slow moving low pressure system maintains influence. This will
solidify an extensive canopy of LIFR/IFR stratus, with an
accompanying reduction in visibility. Dense fog is not expected, but
visibility may occasionally dip to 1 mile at times through the
night. A gradual increase in ceiling heights with time through the
day. This will bring a transition into MVFR during the afternoon.
Winds remain modest from the northwest this period.

DTW THRESHOLD PROBABILITIES...

* High for ceiling at or below 5000 ft through Friday.

&&

.PREV DISCUSSION...
Issued at 301 PM EST Thu Nov 14 2024

DISCUSSION...

Scattered rain chances linger through this evening into early
tonight as occluded low pressure slides along the state line. That
said, intensities and coverage wane through the remainder of the day
as the parent mid-upper trough rapidly dives towards the mid-
Atlantic with central CONUS ridging aggressively building in its
place. Dry conditions largely in place by Friday morning with the
potential exception of the Thumb where persistent northerly flow off
Huron supports a few lake effect showers/drizzle. Temperature
recovery is muted Friday as northerly surface flow, lingering
thermal troughing, and remnant cloud cover all work to keep highs in
the lower 50s (which still is a couple degrees warmer than average
this time of year).

Surface high pressure becomes established directly over southern
lower MI by Saturday. While forecast soundings remain conservative
to the degree low level moisture is able to be scoured out below the
high, there should be enough drying to support a mix of sun and
cloud rather than mostly cloudy skies. Temperatures hold similar to
Friday in the lower 50s given the same thermal airmass and
light/variable surface winds. Ridge axis shifts to our east by
Saturday night setting up modest SW lower level flow resulting in
respectable WAA as 850mb temps climb to around 10C by Sunday morning
(up from 3-4C). This pushes high temps solidly above average in the
upper 50s.

Amplified upper pattern across the CONUS next week brings active,
unsettled weather back into the central Great Lakes. First of these
troughs and its associated closing low lifts out of the upper Plains
into Northern Ontario latter half of the day Sunday eventually
sending a weak cold front through SE MI late evening. Rain chances
look limited along this front as system-relative flow has a large
parallel component to the frontal orientation in addition to the
fact the main wave/PV pool passes well to north and SE MI looking to
reside below the right exit region of the jet increasing upper level
convergence. Better rain chances arrive mid and late week as a
series of strong mid-level waves eject out of the Desert SW/
southern Plains and into the Midwest/Great Lakes.

MARINE...

Low pressure shears toward the mid-Atlantic tonight, allowing
widespread shower coverage to gradually wane through the evening.
Spotty shower coverage however lingers into Friday as saturated low
level thermal profiles stay neutral to weakly unstable through the
day. All Small Craft Advisories come to an end by 03z (10pm local)
tonight as the pressure gradient relaxes and winds veer offshore by
Friday afternoon. Drier conditions move in Friday night as high
pressure and upper level ridging move in, leading to quiet marine
conditions for Saturday and most of the day Sunday. An active period
is then anticipated for all of the Great Lakes next week, starting
Sunday night as Canadian low pressure drags a cold front across the
northern lakes Sunday night. A second low will already be developing
over the central CONUS by this time, and will be one to watch for a
major pattern shift by middle of next week.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory until 10 PM EST this evening for LHZ441-442.

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

$$

AVIATION.....MR
DISCUSSION...KDK
MARINE.......MV

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at www.weather.gov/detroit.