Strongs, Michigan Weather Forecast Discussion

686
FXUS63 KAPX 201035
AFDAPX
Area Forecast Discussion
National Weather Service Gaylord MI
635 AM EDT Sat Sep 20 2025
.KEY MESSAGES...
- Scattered showers and a few storms today, focusing west of US-131
  mainly, spreading northeast tonight.
- Showers, thunderstorms tonight through Sunday night with moderate
  rainfall possible for portions of N MI (~30-50% chance for >0.50").
- Rain chances remain into early next week.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 255 AM EDT Sat Sep 20 2025
Pattern Synopsis and Forecast:
General troughing is expected across the Upper Midwest today with a
negatively tilted piece of that feature slowly moving east to
northeastward with time into tonight. Best lift from this feature
will likely remain mainly to the west of N MI through today. That
being said, the cooler temps aloft, in addition to several little
associated pinwheeling low level warm advection/upper level
divergence episodes, could trigger scattered showers and some
thunderstorms today. Focus will be west of I-75, and even more so
south and west of US131 through this afternoon.
Low level jet begins to ramp up tonight with moisture advection
expected as a warm front lifts northward. Additionally, upper
divergence and lift swings through northern MI due to the trough
impinging from the west and moving northeast and the frontal
boundary moving northward. Thus, the precipitation coverage should
begin to increase during the overnight hours, and again on
Sunday/Sunday night.
Primary Forecast Concerns:
WV satellite imagery shows a weak band of deformation that coincides
with a band of weak shower activity from central upper MI down into
Lake MI ~07Z. In theory, this feature should shift a little
northward into this morning and not entirely sure this has an actual
impact on the shower and storm potential today.
Main concern through this period will be the shower and thunderstorm
threat. Warm and moist advection into tonight will result in PWs
climbing to ~1.3" give or take which is well above normal for this
time of year. Instability will be a limiting factor overall,
especially tonight, although there may be a modest pocket that
develops within the favored precipitation area today (west and south
of US131). Thus, any more robust showers or thunderstorms today and
tonight could produce locally heavy downpours as a main concern,
especially if enough instability is able to interact with the
lift/front and low level jet tonight. Some hi-res guidance are
trying to hint at that possibility to some extent, but not ready to
really jump on a significant heavy rain threat based on the suite of
available guidance. Still, the lift and moisture do support the
potential for locally heavy downpours for some today (slow moving
storms) and tonight (low level jet/frontal induced). Best potential
for wetting rains though will be around Grand Traverse Bay and
southwest through this time frame.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 255 AM EDT Sat Sep 20 2025
Day 2-3 (Sunday - Monday):
Short wave on the southeast periphery of an approaching upper trough
will be swung northward into MI Sunday and into the overnight hours.
This will aid shower and storm potential later Sunday and Sunday
night. Thus, expect another round of showers and storms some time
during the day on Sunday and into the overnight depending on exactly
when this short wave swings on through. Swath of precipitation will
be moving from southwest to northeast with time, perhaps slightly
focusing across interior and northeast lower instead of
northwest lower this time. Combination of modest instability and
shear could result in a stronger storm or two (although guidance
seems to be trending down in regards to instability on Sunday), with
downpours/locally heavy rain the primary concern (well above normal
moisture with PWs ~150%+ of normal for this time of year). Modest to
moderate rainfall will be possible across a decent chunk of northern
MI when all is said and done through Sunday night, with ENS guidance
showing medium potential (~30-50% chance) for over half an inch of
rain, slightly favoring west of I-75. Amounts exceeding 1" of rain
will be possible within any convective rainfall.
Combination of trough center moving across eastern upper, H500 speed
max on the southern edge of the trough, and modest instability and
moisture will result in the potential for additional showers and
thunderstorms on Monday. Similarly, progged soundings from the GFS
do show a breaching of convective temperatures for some point
locations Monday afternoon, so that could initiate showers and
storms as well if able to overcome the subtle low-mid level warm
temps and instability is able to manifest as currently forecast.
We`ll fine tune the forecast in the coming shifts but showers and
storms are possible on Monday afternoon within a modestly unstable
(assuming there`s enough daytime heating) and sheared (~25-30 kts
BWD) environment.
Days 4-7 (Tuesday - Friday):
Lingering precipitation is possible on Tuesday as subtle troughing
aloft remains in addition to instability. High pressure does build
in from the north thereafter, although low level moisture does not
completely scour out. Nevertheless, the main feature(s) to watch in
the extended will be the ridge building across Ontario and vicinity
overtop of an upper low across mid MS valley-ish. Two solutions
currently at play within the deterministic guidance, upper low
is pulled northward and thus widespread precipitation chances
later in the week (GFS). Conversely, the upper low stays
suppressed to the south across the ~Southeast (CMC/ECMWF). More
of the ensembles (GEPS, EPS) point towards the latter solution,
so we`ll nudge in favor of the lesser precipitation chances at
this time. Otherwise, seasonable temperatures anticipated during
this time frame.
&&
.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 625 AM EDT Sat Sep 20 2025
VFR conditions for most terminals through 00Z. SE/E winds will
become 10kt with G15kts after 14Z today as a system approaches
from the west. Skies will continue to fill in and become BKN-OVC
at 10kft or above. Chances for ISO showers over KTVC/KMBL will
continue through 00z, then coverage will increase. Cigs will
eventually lower after 00Z over NW lower terminals to around 2
kft as SHRA chances increase for most terminals after 06Z.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through late tonight for MIZ017-018-
     088-096-097.
MARINE...Small Craft Advisory until 4 AM EDT Sunday for LHZ345>348.
     Small Craft Advisory until 4 AM EDT Sunday for LMZ341-342.
     Small Craft Advisory from 11 AM this morning to 4 AM EDT
     Sunday for LSZ321-322.
&&
$$
SHORT TERM...JLD
LONG TERM...JLD
AVIATION...ELD

NWS APX Office Area Forecast Discussion