334
FXUS63 KAPX 220445
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1145 PM EST Thu Nov 21 2024

.KEY MESSAGES...

- Lake effect/induced rain showers continue through portions of the
  weekend.

- Rain and snow next week with colder temperatures.

&&

.UPDATE...
Issued at 925 PM EST Thu Nov 21 2024

Low pressure now centered along the Michigan/Indiana border is
in the process of transferring energy to a deeper/main low
centered off the Atlantic coast. Northerly low level flow is
becoming better established across the Western Great Lakes...and
combined with sufficiently cold air...is in the process of
producing scattered lake-induced rain showers targeting our
Lakes Michigan and Huron shoreline areas. This precip will
continue to become better established during the overnight
hours...with some light snow possibly mixing in with a few light
rain showers if they happen to reach further inland where temps
will be slightly cooler. No snow accumulation is expected in
these areas. Have made some minor adjustments to precip type
based on slightly cooler temps now thru the next few hours.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 226 PM EST Thu Nov 21 2024

Dry slotting firmly overhead as breaks in the clouds have resulted
in peeks of sun. Combined with warm grounds, short work has been
made of last night`s snowfall across the interior elevations.

Low pressure exiting to the south will drag additional vorticity and
moisture across the region, which, with convergent flow at the
surface, should be just enough to force off some lake effect
convection (in the form of rain) later tonight and into tomorrow as
winds turn more northerly. Not an obnoxious amount of QPF expected
from this lake effect activity, with the majority of the rainfall
being confined to west of US 131 and east of M-33 in northern lower,
and west of the Soo in the eastern Yoop due to the northerly flow.
Most spots see anywhere from 0.05-0.15" of rainfall. This activity
will taper some in the afternoon hours on Friday as forcing becomes
a bit more disjointed and low level lapse rates wane. Result will be
a transition to an occasionally drizzly regime with time later
Friday afternoon for the lake effect areas, with the interior of
northern lower largely holding overcast and dry.

Temps tonight range from near 32 inland, to near 40 along the
lakeshores. Temps Friday hold in the 40s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 226 PM EST Thu Nov 21 2024

Pattern Forecast: At the start of the period Friday night, shortwave
mid-level ridging is expected to be nosing into northern Michigan
sandwiched between two closed mid-upper level low pressure systems --
one over the eastern seaboard and the other over far northern
Manitoba making eastern headway to near Hudson Bay. Nevertheless, a
sufficient over-water thermal gradient and energy pinwheeling around
that system to our north likely to continue precip chances, at least
in the lake belts. A general reprieve expected this weekend under
higher surface pressures and a weak warm advection regime. Potential
for a return of more active weather arrives early next week and
continues at times through the remainder of the long-term (and
beyond) as latest trends continue to support a system or two
spinning up lee of the Rockies and trekking through the middle of
the country, along with more notable arctic air spilling into the
Great Lakes.

Forecast Details: Lake effect/enhanced showers expected to continue
Friday night, especially in the typical lake belts of eastern upper
and northwest lower. Primary p-type expected to be rain, but
forecast thermal profiles aren`t too far off from mixing with some
snow across the higher terrain. Isolated to scattered rain shower
chances continue Saturday across those same areas, albeit in a
slowly diminishing fashion with warm low-mid level warm advection
expected to become more robust Saturday evening and overnight.

Early next week (Monday/early Tuesday timeframe), ensemble trends
still favor lee side cyclogenesis over the Plains with low pressure
trekking across the Great Lakes region. Plenty of uncertainties with
respect to the details, although rain potentially changing to some
backside snow seems like a reasonable solution at this point. Beyond
this early week system, ensemble means still point toward ridging
building off the west coast, establishing cross polar flow with
colder air sinking south into the northern tier of the CONUS. If
this trend holds, several opportunities for snow, both system and
lake effect, would seem to be on tap for mid-late next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1145 PM EST Thu Nov 21 2024

Deep low pressure pivoting around the NE US will transfer energy
off the Atlantic Coast...leaving Michigan under northerly low
level flow and sufficiently cold air to generate lake enhanced
rain showers over the next 24 hours. Prevailing conditions will
remain low VFR/MVFR overnight thru Friday night...with the most
persistent rain showers focused along our Lakes Michigan and
Huron shoreline areas. Surface winds will remain from the north
at around 10 kts overnight...strengthening to 15 to 25 kts
Friday into Friday night.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory until 10 PM EST Friday for LHZ345>349.
     Small Craft Advisory until 1 AM EST Saturday for LMZ323-341-
     342-344>346.
     Small Craft Advisory until 7 PM EST Friday for LSZ321-322.

&&

$$

UPDATE...MLR
SHORT TERM...HAD
LONG TERM...MJG
AVIATION...MLR