614
FXUS63 KDTX 150750
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
250 AM EST Fri Nov 15 2024

.KEY MESSAGES...

- Cloudy skies hold today.

- Temperatures above normal over the weekend, and mainly dry.

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

&&

.DISCUSSION...

A gloomy start, with clouds likely persisting through the day
underneath a lowering subsidence inversion as an upper level ridge
builds over the Western/Central Great Lakes during the day. Spotty
sprinkles/very light showers also possible as modest cape is
generated with cloud depths ~4kft. Limited diurnal bounce in
temperatures expected, lower 50s at best.

If low clouds are able to dissipate in the evening, we could be set
up for fog tonight as surface high will arrive over southern Lower
Michigan. Favoring low clouds for now, but confidence is low and
skies certainty could clear out, which would favor colder mins than
currently forecasted (upper 30s/near 40 degrees).

Upper level ridge (~573 DAM at 500 MB) building further and directly
overhead of the Central Great lakes on Saturday, with return low
level flow around the departing high kicking in late in the day.

Strengthening height fall center tracking through the Dakotas on
Saturday and through Lake Superior Sunday morning. Low level
moisture axis/850 MB Theta-e ridge tracking through southeast
Michigan Sunday afternoon, but the mid levels are warm and dry,
making measurable rain hard to come but. Perhaps a little light rain
activity from the low level isentropic ascent, but more than likely
the NAM is too moist down low.

The forecast next week will hinge on the strong 500 MB low over Baja
California/northern Mexico and the interaction with the copious
amount of upper level energy coming out of the Gulf of Alaska and
then digging southeast through the Pacific Northwest Sunday Evening.
Good clustering of the Euro ensembles with the surface low tracking
north-northeast through Iowa/Minnesota on Tuesday, but then likely
translating southeast. Significant differences for the mid/late week
in how strong the system ends up being and the amount of cold air
infusion, as the Canadian and Euro have trended colder, with 850 MB
temps of -6 to -8 C cold enough for snow underneath the cold cold/mid
level circulation, but that looks to be just south, over the Ohio
Valley at the present time.

&&

.MARINE...

The low pressure circulation responsible for yesterday`s unsettled
weather has weakened overnight, and will eventually dissolve over
Lake Erie today. This has led to relaxation of the wind field with
sustained northwest flow of 5 to 10 knots expected through the day.
Lingering low level moisture and neutral to weakly unstable thermal
profiles maintain shower chances through the day. High pressure then
builds in tonight and Saturday, affording a brief period of quiet
marine conditions and dry weather for the daylight hours Saturday.
By Saturday night, flow flips to the south in advance of the next
low pressure system and cold front that will impact the Great Lakes
on Sunday. This system brings the next chance for rain to the area.
In addition, winds and waves will ramp up as a tight gradient around
the low generates a low level jet core of ~35 knots. Warm sector
setups like this one however tend to underperform when it comes to
momentum transfer, so expecting gusts to peak at or below 30 knots.
Unsettled weather then continues into the first half of the week as
another low pressure system lifts into the region.

&&

.PREV DISCUSSION...
Issued at 1151 PM EST Thu Nov 14 2024

AVIATION...

Very moist low level conditions entrenched overnight 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.
Some potential for cloud cover to thin Thursday night, although
confidence in occurrence remains quite low attm. Winds remain modest
from the northwest this period.

DTW THRESHOLD PROBABILITIES...

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


&&

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

$$

DISCUSSION...SF
MARINE.......MV
AVIATION.....MR


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