549
FXUS63 KMQT 150828
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
428 AM EDT Sat Jun 15 2024

.KEY MESSAGES...

- Dry through Saturday before the return of showers and
  thunderstorms later in the weekend.

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

&&

.SHORT TERM /TODAY/...
Issued at 406 AM EDT Sat Jun 15 2024

Water vapor imagery/surface analysis early this morning still show
Upper Michigan under the influence of high pressure centered over
southeast Ontario.  So, it has been a quiet night, and the dry
stretch will persist through today, yet, before the beginning of a
more active period.  Currently, skies are clear across the forecast
area, which is resulting in some cool lows this morning, especially
across the east where ground-based obs are reporting widespread low
to mid 40s.  Elsewhere, temperatures have been a bit slower to fall
over the west and central where 50s are holding steady.  Later
today, expect the quiet, dry weather to continue as mentioned above
with daytime highs topping off in the 60s along the lakeshores and
mid to upper 70s inland.  Winds will become predominantly southerly
at 5 to 15 mph.

&&

.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 /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 140 AM EDT Sat Jun 15 2024

VFR conditions continue the rest of this morning through the late
afternoon. However, as a low pressure approaches from the west
today, expect clouds to continue to fill-in and for cigs to slowly
lower from west to east throughout the day. Some calm to light
southerly winds early this morning pick up a from the south after
dawn into the afternoon hours. Some of the first rain showers could
be seen over KIWD by the end of the TAF period, with KIWD and KCMX
possibly dipping into MVFR conditions by 06z tomorrow.

We could (50% chance) see some marginal LLWS near KCMX early this
morning, but given that it`s so marginal and it`s near dawn (when
mixing and gustier winds could make it to the sfc), I`m not going to
include it in the TAF at this time. We could also see some marginal
LLWS at all the TAF sites come tonight, but the chances are again
still rather low (30%).

&&

.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...TDUD
LONG TERM...LC
AVIATION...TAP
MARINE...LC