481
FXUS63 KAPX 141954
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
354 PM EDT Sun Jul 14 2024

.KEY MESSAGES...

- Showers and storm chances early Monday morning and afternoon

- Shower/thunderstorm chances Monday evening and Monday night. A few
strong storms will be possible, with the primary hazards of damaging
winds and locally heavy rainfall.

- Cooler, less humid weather Tuesday through the end of the
  week.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 306 PM EDT Sun Jul 14 2024

Pattern Synopsis and Forecast:
A stronger upper level ridge remains anchored over the central
Rockies through the short term period. West winds aloft will set
up over the north side of the ridge and reach into the Great
Lakes region. Surface observations depict a wet and warm air
mass has settled in over MI with surface dewpoints in the high
60s and even some sites in the low 70s. Paired with temperatuers
in the low 80s, heat indices are reaching into the mid to high
80s and low 90s for a few sites. Skies do have some bubbling CU
around, with even some higher clouds moving overhead, however
surface temperatures are still able to warm. A lake breeze
boundary is currently forming over the eastern U.P. and will aid
in storm chances later this afternoon and evening. A favorable
environment does exist for isolated to scattered discrete
cconvection along any boundary that can help it initiate this
afternoon into late evening. Isolated storm chances will linger
overnight over northern lower as a stronger complex of storms
will likely move over south/central MI. Patchy fog and haze
could be seen along the northern Lk Michigan coast early Monday
morning, however skies should clear throughout the mid morning
hours. More chances for isolated storms Monday afternoon as
temperatuers warm in a humid airmass. Heat indices could reach
into the low to mid 90s for northern lower in the afternoon
hours.


Primary Forecast Concerns/Key Messages:
Uncertainty is high with Monday`s forecast for thunderstorms.
Exactly when and where storms will occur is up for debate as it
is highly dependent on convection upstream over WI/MN.
Reflection of this high uncertainty can be seen in CAMs, which
output different footprints of storms at different times almost
each run. What we do know, is that the environment is capable of
producing storms that can organize and dump heavy rainfall as
well as some gusty outflow/downburst winds tonight into Monday
afternoon. Chances for these hazards to be severe increase as we
move into Monday afternoon. At this time, the most likely
scenario is that an MCS will form over SE WI later this
afternoon and reaching SW MI overnight. Remnant moisture and
local boundary interactions could help a few storms near M-55
early Monday morning with hazards likely remaining sub-severe.
With skies clearing Monday morning, storms will be possible
along the Lk breeze boundaries however chances are low. The
complex of storms moving to our south could stabilize the air
upstream, resulting in temperatures near the surface slightly
cooler and more dry that the forecast. This would lead to less
chances for afternoon showers and storms Monday afternoon.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 306 PM EDT Sun Jul 14 2024

Pattern Synopsis:
Longwave troughing looks to pivot over the upper Midwest and Great
Lakes through the majority of the upcoming work week. A shortwave
rotating around the base of said troughing will punch over the Great
Lakes Monday night, providing favorable support aloft for a surface
cyclone that is expected to trek across the northern Great Lakes
into Quebec Monday night into Tuesday, sweeping an attendant cold
front across the region during that timeframe. Surface high pressure
then looks to build across much of the north-central CONUS through
the second half of the week as expansive ridging folds eastward
across the continent.

Forecast Details:
Showers/storm chances Monday evening/night -- Relatively high
uncertainty remains in the evolution of shower/storm chances across
northern Michigan beginning Monday evening as much depends on
potential multiple rounds of convection further upstream tonight and
Monday -- specifically the potential for a severe MCS to track
across parts of the Midwest on the other side of Lake Michigan in
the Monday afternoon/evening timeframe. Current confidence is that
any potential MCS to our west/southwest will still leave a window
for convective initiation along the cold front towards the start of
the period. Even greater uncertainty lies in the southwestern extent
of convective initiation along the cold front, but the best chances
for showers and storms Monday evening into Monday night appear to be
across the eastern U.P. and Tip of the Mitt -- further away from the
negative influence of the potential MCS and in closer proximity
favorable upper-level support from the shortwave and low-level
forcing near the cyclone center.

The primary hazards with any strong storms Monday evening into
Monday night will be damaging winds and locally heavy rainfall.
MUCAPE around 1,000 J/kg and deep-layer shear near 40 kts in place
ahead of the boundary will support organized storms, and an expected
quick evolution to a linear storm mode would make damaging winds
more likely. Hail will also be possible, but chances for severe hail
are limited due to aforementioned storm mode and relatively warm
temperatures/meager lapse rates aloft creating less favorable
buoyancy through the hail growth layer. PWATs around 1.6-1.8" in
place will also support efficient rain processes, bringing the
potential for torrential rainfall underneath any strong storms that
may lead to localized ponding on roadways and briefly impact driving
conditions.

Cooler, less humid weather ahead -- After the cold front swings
across the state Monday night, cooler temperatures and less humid
air will follow behind through the rest of the work week. Highs
primarily in the 70s are anticipated Tuesday through Friday. While a
few showers may linger near Saginaw Bay Tuesday, the next main
chances for rain and potentially a few storms will be on Wednesday.
Otherwise, the second half of the week is currently expected to stay
rain-free as high pressure builds into the Great Lakes.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 148 PM EDT Sun Jul 14 2024
VFR conditions across all northern lower terminals this
afternoon with MVFR/IFR cigs over some eastern upper terminals.
Skies should persist over eastern upper terminals for the next
few hours. Lk breeze boundary over eastern upper and northeast
lower could spark ISO SHRA/VCTS after 22Z. Low confidence in
timing and intensity of storms at this time. Winds generally
SW AOB 10kts through the evening. SHRA/VCTS chances linger
through 12Z with some terminals seeing chances for BR/HZ which
could drop vis and cigs into MVFR/IFR categories from 10Z
through 13Z.

&&

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

&&

$$

SHORT TERM...ELD
LONG TERM...DJC
AVIATION...ELD