753
FXUS63 KAPX 262300
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
600 PM EST Tue Nov 26 2024

.KEY MESSAGES...

- Lake effect showers continue this evening over eastern upper and
  the tip of the mitt

- Lake effect snow showers chances continue through Wednesday
  for eastern upper

- Significant lake effect snow expected Friday through the
  weekend.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 315 PM EST Tue Nov 26 2024

Forecast Pattern:

Current satellite and radar show lake effect showers over northern
lower and eastern upper this afternoon. Heavier bands are near the
tip of the mitt and over eastern upper and producing mostly snow
showers. Water vapor satellite imagery depicts a large are of a
closed upper low over most of Ontario and Lk Superior with a
shortwave over northern WI. That shortwave will rotate around and
reach the eastern U.P. later this evening and tonight. This will
help provide more forcing to continue bands of heavier lake effect
snow over Mackinac and Chippewa counties tonight through midnight.
Lower temps aloft, warm lake temps, and NW winds through the CBL
will continue an ideal lake effect environment through Wednesday
morning. By sunrise the bands should be weakening as drier air moves
in from the north. West winds with mostly cloudy skies for northern
MI Wednesday. No precipitation chances for northern lower, but lake
effect could linger for eastern upper into the afternoon hours -
however amounts will not be as impressive as we have been seeing due
to drier air around. Additional snow amounts for the northern parts
of of Chippewa county from 7PM tonight through 7 PM Wednesday are 2
to 4 inches, with less for southern parts of Chippewa and Mackinac
County.

Forecast Concerns:

Snow could taper off a little quicker tonight for eastern upper
after midnight if the shortwave moves east quicker than forecasted.
This could limit additional snowfall and give eastern upper a break
from lake effect snow (after midnight tonight through mid morning
Wednesday). Most CAM guidance has lake effect for Wednesday as NW
winds through the CBL which reaching up to just under 700 mb. This
is still a healthy environment for lake effect, and with warmer lake
waters it will likely continue Wednesday. Snow would fall slower
than today, and SLRs would be higher tomorrow as well which results
in less accumulations.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 315 PM EST Tue Nov 26 2024

.LONG TERM WEDNESDAY NIGHT THROUGH MONDAY/...

     Significant Post Thanksgiving Lake Effect Snow...

As was stated yesterday, a long wave trough is in the process of
setting up across the Great Lakes. This trough will promote arctic
intrusions of cold air as well as abundant lake effect snow over at
least the next one to possibly two weeks. It does look like there
will be a lull in activity Wednesday into much of Thanksgiving Day
with only perhaps a few light snow showers or flurries around.
Extended guidance is then in very good agreement that lake effect
snow activity ramps up Thanksgiving night and continues all the way
into early next week with nearly optimum over lake instability (lake-
850 delta ts in the low 20s). Significant snowfall accumulations are
expected in the usual snow belts of northwest lower and eastern
upper, particularly during the Friday into Saturday time frame.
Moisture appears to be very robust during that time and forecast
model soundings look phenomenal with inversion heights through the
roof (or in this case 20,000 feet+). The dendritic growth zone
(dgz) which is between -12 and -18 C would be entirely in the
sounding promoting large snowflakes which would stack up nicely.
Actually, I can`t remember seeing soundings reaching this
magnitude for this long of a time period (60-72 hours+). The
mean steering flow looks to lock in out of the west northwest
but embedded short waves could cause the flow to waver a bit
from time to time. Either way, would not be surprised if one to
one and a half feet or more of snow falls in some areas during
that time. In addition, gusty winds later in the week could lead
to considerable blowing and drifting snow. Post Thanksgiving
Day travel could become risky at best with near zero visibility
likely at times in the snow belts. With the exception of
Thanksgiving Day when highs will be in the seasonable mid and
upper 30s, temperatures are expected to be a few degrees below
late November averages with highs in the upper 20s and low 30s
and lows in the upper teens to mid 20s.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 600 PM EST Tue Nov 26 2024

W/NW flow lake effect snow showers will continue to impact our
typical snowbelt region this evening...with a gradual diminish
in areal coverage and intensity overnight into Wednesday as low
level ridging and drier air build into the Western Great Lakes.
Low VFR/MVFR conditions will periodically drop to IFR within
heavier snow showers...especially across Eastern Upper and far
Northern Lower Michigan (CIU & PLN). Surface winds will remain
from the west at 15 to 25 kts this evening...diminishing to 10
to 15 kts overnight into Wednesday.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory until 5 AM EST Wednesday for MIZ086-
     087.
     Winter Weather Advisory until 7 PM EST this evening for MIZ095.
MARINE...Small Craft Advisory until 7 AM EST Wednesday for LHZ345>349.
     Small Craft Advisory until 7 AM EST Wednesday for LMZ323-341-
     342-344>346.
     Small Craft Advisory until 7 AM EST Wednesday for LSZ321-322.

&&

$$

SHORT TERM...ELD
LONG TERM...AJS
AVIATION...MLR