175
FXUS63 KAPX 060221
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
1021 PM EDT Sat Oct 5 2024

.KEY MESSAGES...

- Elevated fire danger into this evening.

- Winds turn gusty tonight with a cold frontal passage bringing
  increased shower/storm chances. Some thunderstorms may contain
  severe wind gusts.

- Cooler with scattered lake effect rain showers at times Sunday
  through Tuesday before abnormal warmth returns late next week.

&&

.UPDATE...
Issued at 1021 PM EDT Sat Oct 5 2024

Strong cold front now extends from the Arrowhead of Minnesota
thru Western Wisconsin into Central Iowa late this evening. Area
of strong/marginally severe convection continues to fire along
and ahead of this boundary...fueled by strong low level wind
shear and a narrow relatively weak instability axis. Elevated
nature of this convection and limited instabilty will likely
continue to make it difficult for the stronger winds aloft to
reach the ground as this convection makes steady eastward
progress into and thru our CWA overnight. But if these winds are
able to reach the ground...a few strong to damaging wind gusts
remain possible. Much of our CWA is still in the SPC Day 1
Marginal Risk...and there is certainly a non-zero chance of
damaging winds reaching the surface given winds strengthening to
60-70 kts above 2000 ft just ahead of the cold front. Have made
some adjustments to POPs for the balance of the night. Temps
will be noticeably more mild overnight as compared to last
night`s frosty conditions. Overnight lows will only cool into
the low to mid 50s thanks to ongoing WAA and strengthening low
level winds.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 220 PM EDT Sat Oct 5 2024

Pattern/synopsis: Upper and surface lows will transit northern
Ontario. Associated strong cold front goes thru overnight.

Forecast: Nice afternoon out there, though it is warm, breezy,
and dry enough to make land-management types nervous. Curved
cloud band associated with the incoming cold front is evident on
satellite over central/northern MN. Deep convection initiation
is still several hours away yet, expected toward 00Z over the
western Lk Superior basin and adjoining land areas. This will
race ene-ward, with 0-6km sw winds around 50kt, and 1km winds
50-60kt. This strong warm advection brings a plume of 600-
800j/kg of MuCape into western and northern parts of this
forecast area by 06Z/2am. Instability is elevated, and SbCin is
above 100j/kg. We have a ton of wind to bring down, but do we
the means to do it? A band of high pops will move east across
the area from 11 pm to 7 am, with the highest pops/QPF in
eastern upper MI. Am a little concerned about precip
coverage/QPF in northern lower; some CAMs are more limited in
coverage there.

Sunday, cooler air floods into the region. 850mb temps drop
to -1/-2C in western areas by early evening. Precip should have
largely departed the east by 8, with a lull to start the
morning. The incoming cooler air, and some wraparound/comma head
moisture that intrudes from the nw, with get some lake-effect
to lake-enhanced precip going. With 1000-850mb winds veering wnw
during the day, Chippewa Co will be the first place to see
showers return by midday. Eventually, a broader portion of nw
and n central will see sct showers return during the afternoon.

Temps will stay very mild for this evening, then fall off
overnight as precip and the cold front push in. Lows in the 50s.
We might see a bit of a diurnal temp rise Sunday morning, before
readings fall back into and thru the 50s during the afternoon.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 220 PM EDT Sat Oct 5 2024

Pattern Synopsis / Forecast:

Digging longwave troughing off to our east will leave northern
Michigan sandwiched between an amplifying ridge to the west, as
surface high pressure builds and holds across the western Corn
Belt. This will leave us on the fringe of the troughing with
persistent northwest flow. Some lingering synoptic moisture and
shortwaves pivoting northwest to southeast around the longwave will
allow for some lake induced shower activity as these waves quickly
traverse the region. By midweek, high pressure and the ridging
regime builds back into the upper Great Lakes, bringing back
anomalous warmth and dry weather.

Primary Forecast Concerns:

Lake Induced Showers: In the wake of the passing cold frontal
boundary, a modest setup for moisture from the lakes to be tapped is
well within play Sunday night and periodically through Tuesday.
Better syn optic moisture presence will favor the eastern U.P. and
far northern lower, with activity becoming less prevalent that
farther south and west one goes. With delta-Ts right around 13, this
should be plenty to work with to induce showers in northwest flow
lake effect areas, albeit organization may be a bit disheveled at
times Sunday night. Once this initial shortwave passes, we likely
face a lull in activity to start Monday before another shortwave
pivots through and restarts activity later in the day Monday,
especially with the help of some diurnal heating... again with
activity favoring northwest flow lake effect belts. Activity will
taper some again after this second wave clears Monday night... and
like a scene out of Groundhog Day, yet another shortwave passes
through, flaring up some more lake induced rain showers in the
northwest flow belts later in the day Tuesday. Eventually, this
activity will clear out by Tuesday night as high pressure returns...
with drier weather expected to return for the remainder of the
forecast period. Along with the drier weather will come an increase
in temperatures... with highs climbing from the 50s Monday -
Wednesday... bumping into the mid-upper 60s Thursday and surging
well into the 70s by the week`s end. Overnight lows will largely be
in the 30s and 40s (perhaps near or below 32 across interior
northern lower at times) before bumping into the 40s by Friday
night.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 700 PM EDT Sat Oct 5 2024

A strong cold front will sweep thru the Western Great Lakes
region tonight into Sunday morning...producing a line of
potentially strong/marginally severe convection along and ahead
of it. In addition to this convective development...strong LLWS
will develop in advance of the cold front tonight...impacting
all Northern Michigan TAF sites. VFR conditions will drop to
MVFR as this convection develops and impacts our area. SE
surface winds of 20 to 30 kts will shift to the SW overnight...
and eventually to the W/NW on Sunday in the wake of the cold
front. Some higher gusts are possible over the next 24 hours as
well.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Gale Warning until 8 AM EDT Sunday for LHZ345-346.
     Gale Warning until 10 AM EDT Sunday for LHZ347>349.
     Gale Warning until 5 AM EDT Sunday for LMZ323-341-342-344>346.
     Gale Warning until 5 AM EDT Sunday for LSZ321-322.

&&

$$

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