185
FXUS63 KAPX 180515
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
115 AM EDT Sat Oct 18 2025

.KEY MESSAGES...

- Another round of rain with embedded storms tonight and Saturday.

- Still watching the potential for a more robust true fall storm to
impact the area Saturday night into Sunday...bringing periods of
heavy rain and gusty winds (gales on the big waters?)

- Well above normal temperatures to kick off the weekend trend
cooler to end it.

- Cooler and still active at times next week.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 241 PM EDT Fri Oct 17 2025

Pattern Synopsis/Forecast:

Warm front in the process of sweeping north across the area this
afternoon, made to do so by maturing southwest flow between eastern
Great Lakes centered high pressure and shortwave trough/attendant
surface low pivoting up into southern Manitoba. Band of showers,
driven by mass convergence/isentropic upglide and rather intense
moisture advection within low level jet has exited our area to the
east...although plenty of clouds still linger. Another mild mid-
October day...with current temperatures punching up into the 50s
and 60s across the Northwoods.

Warm front will continue to bow north this evening as upstream cold
front slowly works east into the western Great Lakes tonight and
Saturday. Classic nocturnal re-development of low level jet along
and ahead of this front...not only bringing renewed deep layer
forcing but also a surge of anamously high moisture into northern
Michigan by later tonight into Saturday morning.

Primary Forecast Concerns:

Addressing additional shower evolution and embedded thunderstorm
potential later tonight into Saturday.

Details:

Target area for additional showers by later this evening will be
found across eastern upper Michigan as leading edge of deeper
moisture advances east ahead of that slow moving cold front. Showers
will gradually develop east with time later tonight into Saturday,
likely gradually organizing in the process as low level jet matures.
Pattern recognition definitely supports a slow moving band of fairly
organized and locally heavy showers by later tonight and Saturday
morning, with just enough elevated instability to promote a few
embedded non-severe thunderstorms as well...with these only adding
to the rain intensity at times. Definitely not seeing any hydro
concerns with still very dry soils, but wouldn`t be surprised at all
to see some locations come in with well over half inch rain amounts
by Saturday afternoon. Most intense moisture advection works east
with time on Saturday...taking what should be a weakening
(dissipating low level jet support) band of showers along with it
into northeast lower Michigan.

Unseasonably mild weather to continue, with lows tonight only
dropping into the 50s (much closer to normal high temperatures) and
highs Saturday well up into the 60s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 241 PM EDT Fri Oct 17 2025

Pattern Synopsis/Forecast:

Long term continues to look much more fall-like, with a more active
weather regime set to visit the Great Lakes. Initial concern centers
on what looks to be an intense shortwave trough expected to rotate
across the region Saturday night into Sunday. Good to excellent
agreement another robust wave digs into the Great Lakes on Tuesday,
bringing another bout of wet and windy weather along with it.

Primary Forecast Concerns:

Weather associated with this weekends deepening wave, with secondary
focus on addition shower chances through next week.

Details:

First real fall system still looks to visit the area Saturday night
into Sunday as vigorous wave spawns cyclogenesis along slow east
moving cold front. 125+ knot upper level jet core and digging
shortwave trough definitely supports rather robust low development
as it moves northeast along the baroclinic axis Sunday. Still some
question on overall depth and exact propagation of this low...but
current trends support a steadily deepening low pivoting up across
southeast Michigan into Lake Huron. Intense forcing via deep layer
jet support working over a still very moist airmass (precipitable
water values up to and over an inch) should support some well
organized and locally heavy rains. Could easily see an additional
inch or more of rain by later Sunday...with pattern recognition
currently suggesting areas down near Saginaw Bay targeted for the
heavier rain totals where low level jet support appears maximized
(supporting embedded deeper convective elements). More broad soaking
deformation-driven rains to the northwest of the low...currently
slated to impact much of our area by later Saturday night into
Sunday. System should also produce some gusty winds...especially
over those big waters where gale force gusts appear increasingly
likely within favored cold air advection mixing regime. Again, still
plenty of time to see how this all unfolds...and changes
(perhaps significant)...are more than expected.

Brief break in the active weather Sunday night into Monday before
that next vigorous wave drops southeast out of Canada. Unlike its
predecessor, this one will not have a direct Gulf of America
moisture connection. However, simple breadth of dynamics and what
looks to be a growing lake moisture connection supports some wind-
driven showers Monday night into Tuesday. Again, could be looking at
another round of marine headlines, with at least early support for
more gales on those big waters.

Additional shower chances look to continue through the remainder of
the extended, both from lake processes and passing of additional
weaker waves within overhead troughing. As mentioned
yesterday...mandatory utilization of a consensus blend guidance
approach forces a prolonged period of shower chances...when in all
likelihood actual better chances for additional rain will be
relegated to much shorter time windows than the outgoing forecast
currently suggests.

Definitely more traditional October high temperatures, with readings
probably not getting out of the 40s for some areas by Tuesday and
Wednesday. Clouds, winds, and showers will keep overnight lows
elevated and likely several degrees above normal.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 115 AM EDT Sat Oct 18 2025

Prevailing VFR for much of tonight, but SHRA to affect all
sites thru sunrise, with the exception of APN as a cold front
approaches. This will result in several instances of temporary
reductions to MVFR in CIG and VSBY. Exception is CIU, which may
dip into IFR and linger there for much of the day Saturday. A
brief lull to VFR seems likely later Saturday before the next
system approaches from the south. Result will be the onset of
what may be a prolonged period of IFR at the very end of the
forecast period, perhaps even LIFR due to FG / BR and very low
CIGs.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Gale Watch from Sunday afternoon through late Sunday night for
     LHZ345>349.
     Small Craft Advisory until 6 AM EDT early this morning for
     LHZ346>349.
     Small Craft Advisory until 6 AM EDT early this morning for
     LMZ323-341-342-344>346.
     Gale Watch from Sunday morning through Sunday evening for
     LMZ323-341-342-344>346.
     Small Craft Advisory until 6 AM EDT early this morning for
     LSZ321.
     Gale Watch from Sunday afternoon through Sunday evening for
     LSZ321-322.

&&

$$

SHORT TERM...MSB
LONG TERM...MSB
AVIATION...HAD