720
FXUS63 KAPX 230255
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
955 PM EST Fri Nov 22 2024

.KEY MESSAGES...

- Scattered light rain showers continue across parts of northern
  today and tonight.

- Lingering lake effect rain (with a few snow showers) on Saturday.

- Rain and snow early next week.

- Colder temperatures from Tuesday on with periodic lake effect
  snow chances.

&&

.UPDATE...
Issued at 955 PM EST Fri Nov 22 2024

Low level cyclonic flow lingers across the Western Great Lakes
region along the back side of departing low pressure now
centered along the Atlantic Coast. Back edge of synoptic
moisture is just clipping our eastern CWA...producing a ribbon
of lake enhanced rain showers impacting our Lake Huron shoreline
areas. Lake effect rain showers continue to stream into portions
of Eastern Upper and NW Lower Michigan...mainly along and west
of US-131. No snow is mixing in with the rain as temps hover in
the upper 30s and lower 40s. Residual synoptic support and
moisture will shift east of our CWA overnight...but lake effect
rain showers will continue to stream into areas targeted by N/NW
low level flow. Again...do not expect any snow mixing in with
the rain given expected overnight lows in the upper 30s.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 206 PM EST Fri Nov 22 2024

Current Overview / Pattern Synopsis:

Occluded / vertically stacked low pressure system over New England
will continue to slowly move eastward as longwave troughing slowly
moves eastward, being forced by ridging over the Plains. Colder air
aloft will remain in place, partially reinforced by a subtle impulse
cresting the ridging and becoming more ingested into the flow around
the longwave troughing. Result will be a flare up in shower activity
for Saturday as winds turn more northwesterly and lake induced
showers continue.

Forecast Details:

Cyclonic flow and stubborn low level moisture, coupled with just
enough colder air aloft have been sufficient in generating lake
effect convection, with a largely northerly component to the wind.
Expectation is that lake effect shower activity carries into
tonight, primarily favoring the Grand Traverse Bay region and
northeast lower. Orographic lift influences will also continue to
provide enough forcing to keep mist / drizzle around across north
central lower (in particular, the higher terrain near Gaylord). Once
winds turn more northwesterly, expecting the more traditional lake
effect regions to have better shower coverage later tonight and
through the day Saturday. Given mild temperatures in the mid-to-
upper 30s tonight, not anticipating any impacts from snow, and it`s
almost safe to say that we will be free of snow tonight. For
Saturday, CAM soundings show steepened low level lapse rates, which
may be enough to generate some rather beefy lake effect showers, the
most potent of which could easily have some graupel mixing in at
times. The higher probabilities of this occurring favor the
northwest flow belts of NW lower and the eastern Yoop, and perhaps
over toward Presque Isle County off of Lake Huron. MaxTs on Saturday
range from the lower 40s across the eastern Yoop and the higher
terrain of northern lower to the mid-to-upper 40s on the immediate
lakeshore locales.

&&

.LONG TERM /SATURDAY THROUGH FRIDAY/...
Issued at 206 PM EST Fri Nov 22 2024

Pattern Synopsis: Period begins with low amplitude ridging over
much of the lower 48 states. The ridge axis is forecast move
east of the western Great Lakes by late Sunday night/early
Monday morning. Then, two short wave trofs approach the region
to start the work week, the first coming nearly due east off the
Pacific Coast, while the second dives southeast out of eastern
Canada. These features will partially phase over the western
Great Lakes Monday night as an associated surface low crosses
the region. A persistent colder northwest flow exists across the
region behind the early week system.

Forecast Details: Relatively quiet weather is anticipated into
Sunday night as upper-level heights rise with the
approach/passage of the aforementioned ridge and over-lake
instability decreases. Still may be a few spotty showers
Saturday evening before the slightly warmer air aloft arrives,
but they will be minimal if they occur. Some model guidance
suggests showers may develop in the WAA/isentropic ascent regime
on the back side of the departing ridge, but moisture appears to
be lacking for much precipitation before during the day Monday
when better forcing and deeper moisture arrive. Most of the
precipitation on the warm side of the Monday/Monday night system
should be in the form of rain.

Once the early week system departs, colder air and deep
northwest flow settle into the region for most of the rest of
the forecast period. This setup is conducive for lake effect
snow showers from time to time, especially across the favored
northwest flow snow belts. While it is too soon to forecast
specifics, some snow accumulation is possible during this
colder/northwest flow period. This is something that will need
to be watched closely during the heavy holiday travel period.

Temperatures will be at or below normal through the period which
is something we haven`t said much lately.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 600 PM EST Fri Nov 22 2024

Light NW low level flow lake effect rain showers will continue
to fall across much Eastern Upper and Northern Lower Michigan
tonight into Saturday. Prevailing conditions will remain MVFR
for the next 24 hours. Surface winds will remain from the NW at
10 to 20 kts.

&&

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

&&

$$

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