400
FXUS63 KAPX 160753
AFDAPX

Area Forecast Discussion
National Weather Service Gaylord MI
353 AM EDT Sun Jun 16 2024

.KEY MESSAGES...

- Multiple rounds of showers into this evening.

- Isolated severe storms, locally heavy rainfall possible
  tonight.

- High heat and humidity begins this Monday and continues
  through the entirety of the long term forecast period.

- Chances of showers and storms expected at times this week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 351 AM EDT Sun Jun 16 2024

Pattern Synopsis:

Mid/upper-level ridging over the Great Lakes will slide east as a
shortwave quickly lifts across the region this afternoon and
evening. The associated surface response looks to work across
Wisconsin/far northern Great Lakes into tonight. More expansive,
dominant ridging will establish itself over most of the CONUS east
of the Mississippi River by Monday morning.

Forecast Details:

Multiple rounds of showers into this evening -- Ongoing light rain
showers on the periphery of low/mid-level warm advection will
continue over the next few hours before exiting to the northeast
later this morning. A brief break in rain chances is anticipated
through the remainder of the morning before a second round of
showers associated with the aforementioned shortwave works in from
the west beginning early this afternoon and will persist into this
evening. Dry low-level profiles will work to inhibit heavier
rainfall for a time, despite saturated profiles aloft. Little to no
thunder is anticipated with this activity given the lack of buoyancy
from moist adiabatic profiles aloft.

Isolated severe storms, locally heavy rainfall possible tonight --
As warm, moist advection continues across the Great Lakes, steep
lapse rates will arrive on the heels of aforementioned activity to
provide ample elevated instability to support thunderstorm chances
later this evening and tonight. Current confidence in how potential
convection later this evening and tonight will evolve is low.
Additional scattered storms may form after previously mentioned
showers depart east along/to the north of the partially modified
outflow boundary. Where exactly this boundary sets sets up, and
if/how much convection forms along it are the main sources of
uncertainty. With that said, the potential for west-east training
convection exists in the vicinity this boundary later this evening
and tonight -- and with PWATs near/exceeding climatological max
values and ample instability in place, locally heavy rainfall of 1"
or more will be possible across far northern lower/eastern upper
Michigan should training convection develop. An isolated severe
storm or two cannot be ruled out as well, with the primary hazards
being large hail and gusty winds.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 351 AM EDT Sun Jun 16 2024

Previous forecast discussion remains true as midlevel subtropical
ridging is expected to build this Monday across the eastern half of
North America and remain in place for the majority of the long term.
This pattern will support a hot and humid air mass to advect from
the Gulf region into the Great Lakes region.

Aformentioned ridging will start to slowly break down throughout the
work week, but keep temperatures well above average for mid June.
The baroclinic zone is set to remain north of the CWA, but embedded
height disturbances along the ridge will continue chances of showers
and storms at times this week, but no heavy precipitation or severe
weather is expected at this time.

Primary Forecast Concerns/Key Messages:

-High heat and humidity begins this Monday and continues through
 the entirety of the long term forecast period: Hottest days of
 the long term remain to be Monday and Tuesday as temperatures
 surge into the mid 90s south of the bridge. No aid from the
 heat is expected with overnight lows as dew points remain in
 the upper 60s to low 70s, prohibiting efficient radiational
 cooling. Heat will slightly relieve itself by the midweek, but
 highs will still remain well above average for mid June with
 most locations seeing highs in the 80s through the Friday
 /Saturday timeframe. Temperatures are expected to remain just
 below advisory criteria for now, but it would not be too
 surprising if one is later issued due to the rarity of the
 event and the vulnerable populations of the CWA (lack of
 central air in homes compared to other parts of the country).

-Chances of showers and storms expected at times this week:
 Chances of convection are set to continue at times this week as
 the heat wave occupy the Great Lakes Region. Aformentioned
 height disturbances are expected to remain north of the CWA,
 but scattered thunderstorms can fire off for a few locations
 from diurnal heating or along lake breeze boundaries. No heavy
 precipitation or severe weather is expected, but thunderstorms
 could provide a brief aid to the heat to localized areas across
 northern Michigan.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1156 PM EDT Sat Jun 15 2024

Warmer and more humid air will return northward. Mid and high
clouds will be prevalent for the day on Sunday, before clouds
decrease in the evening. Rain chances will be highest on Sunday
in nw lower and eastern upper MI (TVC/PLN/CIU), and have
included a mention of some VCTS at those sites in the afternoon.
Conditions should stay VFR, unless a stronger SHRA or TSRA
impacts a site (which is possible).

Se winds increase slowly tonight, becoming south and gustier on
Sunday. LLWS for part of Sunday evening at CIU/APN.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...Small Craft Advisory from noon today to 11 PM EDT this evening
     for LHZ348.
     Small Craft Advisory from noon today to 2 AM EDT Monday for
     LHZ349.
     Small Craft Advisory from 8 AM this morning to 10 PM EDT this
     evening for LMZ323-341-342.
     Small Craft Advisory from 8 AM this morning to 2 AM EDT Monday
     for LMZ344>346.

&&

$$

SHORT TERM...DJC
LONG TERM...SJC
AVIATION...JZ