288
FXUS63 KMQT 150908
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
508 AM EDT Mon Jul 15 2024

.KEY MESSAGES...

- Marginal risk (category 1 out of 5) of severe thunderstorms today,
main threat is damaging winds.

- Cooler and drier for midweek with the arrival of high pressure.

&&

.SHORT TERM /THROUGH THIS AFTERNOON/...
Issued at 507 AM EDT Mon Jul 15 2024

RAP analysis early this morning shows Upper Michigan under the
influence of weak ridging.  And, current ground-based obs across the
area are already reporting temperatures in the mid to upper 50s
across the interior west with widespread 60s over the remainder of
the forecast area. But, with decent radiational cooling, widespread
upper 50s/low 60s can be expected by daybreak over all of Upper
Michigan. In addition, localized patchy fog has formed along the
MI/WI border out west, and additional visibility restrictions can be
expected through the course of the morning over areas that received
rainfall yesterday.

After the dry conditions early this morning, though, focus quickly
shifts to the next shortwave entering the Upper Midwest and a
surface low that will impact Upper Michigan later today.  Ongoing
MCS over North Dakota could factor into trends later today, but
most likely scenario will be development along and ahead of the
associated cold front progged to move across the UP this
afternoon. With best environment well south of here, the highest
severe threat will be focused over southern WI/IL. Nonetheless,
with another hot day of widespread high temperatures in the 80s
and sufficient dew points in the upper 50s/low 60s, the
environment will be able to destabilize enough for convective
development across the UP as well with the potential for
isolated strong to severe (SBCAPE ~500- 1000J/kg). Main threat
will be damaging winds with subpar mid level lapse rates
mitigating large hail threat and a linear mode in transit with
cold front.

&&

.LONG TERM /TONIGHT THROUGH SUNDAY/...
Issued at 427 AM EDT Mon Jul 15 2024

Starting Monday evening, storms are expected to be ongoing over
central Upper MI ahead of the cold front to the west. As the front
and shortwave push east out of the area, storms exit our CWA by
around midnight. Some of these storms could still be strong to
severe given the bulk shear of ~35-40 kts, lightly capped MUCAPE of
500-1500 J/kg, and 1km helicity ~100 m2/s2. Otherwise the UP returns
quiet as lows settle into the mid 50s to low 60s.

Tuesday and Wednesday, the positively tilted mid level trough over
northern Ontario becomes more vertically oriented as it pivots over
the UP before swinging east toward Quebec and New England for
Thursday. This results in a period of northwest flow, supporting
some light northwest winds gusting up to 20 mph and cooler temps. A
shortwave rotates over the UP on Tuesday ahead of the trough,
yielding slight chances for light showers in the afternoon. With the
main trough pivoting overhead on Wednesday, cloud cover and chances
for showers increase again. That said, a drier airmass will be
advecting in from the northwest, evident in the PWATs dropping to
around 0.7-0.9". Thus, this round will also bring very low impact
accumulations if any. Also with a couple hundred J/kg of MUCAPE, no
severe weather is expected. Highs on Tuesday stay mainly in the 70s
while Wednesday cools off even more with highs only in the mid 60s
to low 70s. Lows Tuesday and Wednesday night dip into the 40s in the
interior with 50s near the lakeshores.

High pressure then builds in from the west Wednesday, continuing to
shift east-southeast over the Great Lakes through the rest of the
week into next weekend. This results in a gradual warming pattern
late next week into the weekend with dry weather likely through the
first half of the weekend. Also during this period, the mid level
ridge over the west amplifies, resulting in troughing over northern
Ontario/Quebec. That leads to the next precip coming from a
shortwave trough dropping south across the Upper Great Lakes late
next weekend, although confidence on timing is low given the spread
in deterministic solutions at this time. From there, ensemble
guidance indicates that the fairly drier pattern is expected to
persist with another sfc high pressure building in from northwestern
Canada as the amplified ridge eventually gives way and shifts
eastward across the CONUS. This means that outside any additional
shortwaves, precip will be largely driven by diurnal heating or lake
breeze convergence moving into next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 114 AM EDT Mon Jul 15 2024

VFR ceilings will prevail in this period. In the wake of evening
showers and thunderstorms, MVFR and IFR fog/mist should develop
overnight at KIWD and KSAW. This should lift and mix out soon after
sunrise. Recent HRRR continues to suggest smoke from upstream
wildfires will filter into the region overnight, continuing into
Monday. With no upstream observations showing obscured visibility at
this point, removed haze from the TAF initially at KCMX, but
introduced it at KCMX/KSAW during the day. This will need to be
monitored in case it needs to be changed. Another round of showers
and thunderstorms is expected to press through the region late
afternoon/evening on Monday. These could potentially impact all
terminals.

&&

.MARINE...
Issued at 427 AM EDT Mon Jul 15 2024

Winds remain light and somewhat variable through this morning as
weak sfc ridging moves over the lake and the next round of storms
approaches from the west. Storms are expected to move over the west
end of the lake this afternoon, continuing east across the lake into
the evening hours. Some of these storms will be capable of producing
gusty winds, frequent lightning, and isolated large hail. Patchy
dense fog is possible, especially in the wake of precipitation.
Winds turn west to northwest behind the cold front Monday evening
into Monday night. Winds are generally expected to remain below 20
kts through the remainder of the forecast period as high pressure
builds in from the west on Wednesday, continuing east-southeast over
the Great Lakes Basin through the rest of the week and into the
weekend. However, the strongest winds up to 20 kts are most likely
on Tuesday and Wednesday.

&&

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

&&

$$

SHORT TERM...TDUD
LONG TERM...Jablonski
AVIATION...JTP
MARINE...Jablonski