666
FXUS63 KMQT 151721
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
121 PM EDT Sat Jun 15 2024

.KEY MESSAGES...

- Dry through today before the return of showers and
  thunderstorms tonight with next system.

- Possible strong to severe thunderstorms Sunday.

- Warmer than normal with frequent chances for showers and
  thunderstorms through next week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 121 PM EDT Sat Jun 15 2024

Clouds pressed into the forecast area this morning, accompanied by
some light rain/sprinkles, thanks to a weak impulse emanating out
of a more vigorous shortwave lifting northeast through Minnesota.
Despite this cloud cover many locations were able to warm into the
upper 60s and low 70s across the west half by 12 EDT while the east,
Keweenaw, and areas near the Lake Michigan only topped out in the
low 60s. Both areas should continue warming this afternoon, with mid
70s in the west and low 70s in the interior east/Lake Superior
lakeshores. Lakeshore areas near Lake Michigan should remain in the
60s given the prevailing off-lake flow. Expect cloud cover to
persist as well, with increasing cloud cover expected across the
interior west as the aforementioned shortwave upstream presses
closer to the region.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 428 AM EDT Sat Jun 15 2024

The pattern becomes increasingly amplified heading into next week as
a mid-level trough digging into western North America amplifies a
ridge from the Great Lakes through the Atlantic Coast into eastern
Canada. This pattern transition will result in much warmer,
summerlike weather for Upper Mi by next week. A series of shortwaves
riding over the ridge will also bring episodes of showers and t-
storms heading into next week with the next best chance likely
occurring Sat night into Sunday.

Ahead of a more prominent shortwave advancing from the Plains, sfc-
850 mb theta-e advection will strengthen on the nose of a developing
50-60kt LLJ as chances for showers and thunderstorms sneak into the
western UP by early evening. PoPs increase from west to east late
Saturday night through Sunday morning as the shortwave passes
through. Although the timing of the shortwave`s arrival will be less
favorable for strong/severe surface-based convection as soundings
initially show weak elevated instability, the impressive
lift/dynamics (0-6 km shear of 40-50 kts or higher) could still be
supportive of stronger storms with gusty winds and small hail
especially as one gets into the daytime hours on Sunday and
instability increases. Heavy rain will be a threat as well with the
stronger t-storms, as PWATs increase to generally 1.5-2 inches.
Showers largely end from west to east during the afternoon.
Temperatures should increase on Sunday, especially west half where
there could be partially clearing in the wake of the passing
shortwave. Readings over the west half should increase into the
lower to mid 80s in the afternoon and this heat combined with dew
points in the 60s will result in muggy and increasingly
uncomfortable conditions. To the east, cloudy skies and the round of
showers/storms should keep temperatures lower, only peaking in the
mid 70s.

Warm and unsettled weather will continue into next week. Monday
through midweek, the Great Lakes will be situated between high-
amplitude ridging over the Eastern Seaboard and deep troughing over
the Rockies. Persistent southerly flow into the area will continue
to pump in a warm, moist airmass; look for highs Monday and Tuesday
to range well into the 80s for most of the area and even a few low
90s readings possible over the interior west half and in the
typically warmer southerly downsloping spots. With dewpoints well
into the 60s, it will get uncomfortably muggy. Given this unstable
airmass and our area situated on the perimeter of the ridge, passing
weak waves will leave us with chances for showers and storms both
Monday and Tuesday, although mid-level capping from the dome of heat
over the area could at the same time keep a lid on some of the
convection. With deep layer shear still at 40-50 knots on Monday,
any convection that pops that day could have a shot of going severe.
Southerly winds will noticeably increase and become gustier on
Tuesday as a midlevel shortwave ripples out of the Rockies with a
surface low likewise closing off and heading into the Northern
Plains, leading to a tightening pressure gradient over the area.
Another strengthening LLJ of 40-50 kts may provide the lift needed
for some additional convection Tuesday night into Wednesday while
the surface low moves through Ontario and sends a frontal boundary
across the area. From midweek onward, temperatures will trend more
towards normal while the heat dome pattern governing the early part
of the week breaks down, although more episodes of convection are
possible Wed-Thu as more shortwaves ride along the frontal boundary
lingering just to our south. Midlevel flow continues to turn more
zonal into next weekend, but weak shortwaves present in model
guidance will be enough to keep in chances for showers and daytime
thunder to finish out the forecast period.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 121 PM EDT Sat Jun 15 2024

VFR conditions this afternoon will deteriorate overnight into Sunday
morning as a system spreads rain into the region. Expect all sites
to fall to MVFR by morning, maybe IFR at KCMX and KIWD. Wind shear
will also be possible at all terminals overnight. Gusty winds will
develop by morning at all sites.

&&

.MARINE...
Issued at 428 AM EDT Sat Jun 15 2024

Initially tranquil winds this morning will increase out of the SE
this afternoon ahead of an approaching shortwave. Expect gusts up
to 20 knots in the eastern half of the lake by the late afternoon.
Wind gusts increase to 20-25 kts for tonight and Sunday, then winds
fall back below 20 kts Monday before increasing out of the SSE again
Tuesday with maybe some gusts to 25 knots over the eastern lake.
Winds fall back below 20 kts again mid week. Waves should generally
be below 3ft for most of the period, but are expected to increase to
around 3-5ft across the eastern half of the lake Sunday.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.

&&

$$

SHORT TERM...JTP
LONG TERM...LC
AVIATION...JTP
MARINE...LC