NWS Forecast Discussion

\n588
FXUS63 KDTX 131103
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
703 AM EDT Fri Sep 13 2024

.KEY MESSAGES...

- Fog is possible during the early morning over the next several
  days.

- Warm, dry, and mostly sunny conditions prevail today through the
weekend and into next week.

&&

.AVIATION...

Fog has a smaller footprint across the area early this morning
compared to recent days, especially along the terminal corridor.
Sunrise observations indicate lower visibility at typically more
sheltered locations suggesting shallow MVFR to brief IFR remain
possible at terminal sites until mid morning followed by just thin
high clouds for the remainder of today. Surface high pressure
spanning the region from the Atlantic coast back west into the Great
Lakes maintains a dry and cloud-free lower atmosphere on light east
to southeast wind, conditions that persist tonight with an overnight
reset on patchy fog toward sunrise Saturday.

For DTW/D21 Convection... Thunderstorms are not forecast today or
tonight.

 DTW THRESHOLD PROBABILITIES...

* None.

&&

.PREV DISCUSSION...
Issued at 337 AM EDT Fri Sep 13 2024

DISCUSSION...

A dry and stable air mass remains in place this morning with
regional obs highlighting a broad 1022mb surface ridge that extends
west from high pressure centered over the northeast CONUS. Patchy
fog development has become evident over the past hour and this will
likely persist through daybreak. Lake moisture advection was
relatively weak overnight so dense fog doesn`t appear to be a
concern at this time.

Little change to the thermal profile compared to yesterday which saw
highs in the 80s. The mid-level ridge strengthens directly overhead
through the day as a rex block sets up with the remnants of Francine
stalling across the mid Mississippi Valley. This results in pretty
healthy subsidence over the area which may cap mixing heights
compared to yesterday but highs in the lower to mid 80s still look
good. Some high clouds associated with Francine may make inroads at
times today but should generally hold to the south with a negligible
effect on temperatures. Meanwhile, smoke models suggest the plume of
high altitude wildfire smoke will stay caught in the anticyclone
overhead for the next few days which will lead to vibrant
sunrise/sunsets with little to no impact on surface air quality.

The 500 mb ridge stays parked over the Great Lakes at around 590 dam
through the weekend while slowly easing eastward with time. This
favors a persistence forecast with little change in the air mass
from day to day. Highs in the 80s and lows in the 50s to lower 60s
will be the norm with plenty of sunshine each day. With the
stagnation of the upper air pattern, the elevated wildfire smoke may
stick around into early next week. Morning fog will also be possible
given prevailing light easterly wind to carry the marine layer
inland each night.

The warm and dry pattern looks to carry well into next week - the
rex block eventually breaks down early in the week but ensemble
guidance favors the longwave ridge holding over the Great Lakes as a
deep trough becomes established over the western CONUS. A handful of
GFS and CMC ensemble members bring QPF to the area in the Wednesday
to Friday time frame with a plume of Atlantic moisture but overall
the ridging is expected to hold steady with the majority of ensemble
members staying dry. CPC 6-10 day and 8-14 day outlooks show high
confidence in warm and dry conditions well into the following week
as well.

MARINE...

Northeastern high pressure continues to influence the region through
the first half of next week. This system maintains dry conditions
and generally light flow across the region. Potential exception is
Lake Erie late today into Saturday where some gusts near 20kts will
be possible as the remnants of Francine tighten the gradient over
the Ohio Valley and far southern Great Lakes.

&&

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

$$

AVIATION.....BT
DISCUSSION...TF
MARINE.......KDK


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

NWS DTX Office Area Forecast Discussion