967
FXUS63 KAPX 190151
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
951 PM EDT Sat May 18 2024

.KEY MESSAGES...

- Warm for a few more days.

- Chance of showers and embedded thunderstorms tonight.

- Chances for showers and storms Monday through Wednesday with
  the potential for stronger storms Tuesday night.

&&

.UPDATE...
Issued at 951 PM EDT Sat May 18 2024

Upstream cold front has reached Central Wisconsin late this
evening. Several areas of convection continue to fire along and
ahead of this front...impacting Western Upper Michigan and
Central Wisconsin attm. Storms have been strong to at times
severe...fueled by a narrow but potent instability axis
featuring MUCAPES nearing 2000 J/kg and LI`s of -5. Primary
severe wx threat has been large hail per LSRs from upstream
offices. SPC Meso Analysis shows a very stable and rather dry
environment across our entire CWA attm. As this cold front
swings thru our CWA overnight...do expect some destabilization
and low level moistening ahead of it...but FROPA during diurnal
instability minimum combined with only limited moist advection
ahead of it should keep any thunder that does develop below
severe limits.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 341 PM EDT Sat May 18 2024

Pattern/Synopsis: 995mb low pressure is north of Winnipeg,
lifting northward. An associated cold front curves to the se
and s, pushing out of MN and into WI. Warm advection ahead of
the front is stronger w of Lake MI than here on our side. This
front will cross northern MI overnight into Sunday morning.

Forecast: A warm day across most of the area. GLR hit 80f at
2pm, the first 80 since October of last year. Se winds off of
Lk Huron is maintaining cooler readings near that lake, on up
into eastern upper MI. Also plenty of stratus/fog in the marine
layer on Lk Huron, right up to our coastlines. Some cu inland
over ne lower MI, otherwise little cloud cover and no precip.
There are some showers ahead of the front in parts of WI and
western upper MI.

A narrow axis of MlCape values around 1500j/kg is upstream, just
ahead of the front. Strong/svr storms could fire there, and SPC
has a slight svr risk. But we have a lot less instability here,
and an unfavorable overnight fropa as for timing. And with the
system lifting northward, the trailing front is getting
increasingly strung out, with weakening low-level convergence.
Precip chances in this forecast area are highest in eastern
upper MI, from very late evening onward. Smaller pops for
northern lower MI, all after midnight. Chance for thunder will
be present, but this elevated and weakening convection should
not be severe. Expect precip to entirely depart or dissipate by
8am. Some fog will get left behind, especially in eastern upper
MI and near Lk Huron.

Min temps in the 50s.

Sunday: Fog/stratus will potentially be an issue to start the
day in the north and east. Weak cool/dry advection and light nw
winds is found across the area by late morning. Should have no
trouble transitioning to abundant sunshine again, which will
more than counter that cold advection. An axis of instability
will develop downstate as the front lays over, but this is
increasingly likely to remain south of our area. Have removed
chances for precip in se areas Sunday afternoon.

For fire wx interests: some very low RH values are possible
tomorrow. Using favored NBM10% guidance take after dew points
down to the lower 30s, and RHs in the vicinity of 20% across
much of the area. Nw post-frontal winds should remain light, and
thus will not advertise elevated fire danger at this time. But
it was considered.

Max temps from low 70s far north (ANJ) to mid 80s far se
(Gladwin/W Branch).

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Issued at 341 PM EDT Sat May 18 2024

PATTERN SYNOPSIS/FORECAST:

Unsettled conditions expected to start off next week as a cold front
stalls and becomes stationary downstate. A trough and its associated
surface low is projected to track into the Midwest resulting in a
slug of moisture being brought into the area for Monday/ Tuesday,
leading to rain chances and possible embedded thunderstorms.
Temperatures will be warmer to start off next week with daytime
highs in the 70s/ 80s, before more seasonable temperatures set in
for mid-week next week (50s/ 60s).

PRIMARY FORECAST CONCERNS:

- Chances for showers and storms Monday through Wednesday with the
potential for stronger storms Tuesday night: A digging trough and
its associated surface low will bring ample moisture into the region
and will work in contingent with a stationary frontal boundary that
is expected to be shoved northward into Northern Michigan through
Monday to produce rain showers and embedded thunderstorms. Guidance
continues to hone in on a wave of energy that will track through the
region Monday night into early Tuesday, which could present the next
round of showers and thunderstorms. Attention then quickly turns to
a potential surface low passing into the vicinity of western Lake
Superior and a cold frontal passage with decent forcing present. It
is still too far out to make any definitive conclusions about this
set-up, but this is definitely something to watch as it has the
potential to create strong thunderstorms, especially Tuesday night.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 703 PM EDT Sat May 18 2024

A cold front will sweep thru Northern Michigan tonight...
generating a line of showers and thunderstorms that will impact
our area overnight. Greatest chance for convection will be
across Eastern Upper and far Northern Lower Michigan where lift
and instability will be strongest. Conditions will drop to MVFR
within some of the heavier showers/storms...and some stratus
and patchy fog are expected to develop again late tonight into
early Sunday across Eastern Upper and NE Lower Michigan. SE wind
under 10 kts tonight will shift to the N/NW around 10 kts
behind the cold front on Sunday.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

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