381
FXUS63 KMQT 121744
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
144 PM EDT Wed Jun 12 2024

.KEY MESSAGES...

- Strong to potentially severe storms possible this afternoon
  and evening with best chances over the far west.

- Gusty winds expected Thursday along with lingering showers
  and thunderstorms.

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

- Warmer than normal temperatures frequent the forecast, with
  some areas approaching 90 for highs by next week.

&&

.SHORT TERM /THROUGH THIS AFTERNOON/...
Issued at 520 AM EDT Wed Jun 12 2024

Current RAP analysis shows a mid level trough centered over far
northeastern Ontario with an embedded shortwave rotating over Lake
Superior. The sfc low is centered below the mid level trough with an
occluded front stretching south through central Upper MI. As these
two features shift east, the occluded front will continue east out of
the UP this morning. Some scattered clouds and isolated showers
ahead of the front in the eastern CWA will continue east with it.
This will leave the UP mostly clear and dry by around the morning
commute.

Today, mid level flow will be fairly zonal over Upper MI as the
trough to the north moves east through far northern Ontario. An
additional trough currently over British Columbia and Alberta moves
east over the Canadian Prairie Provinces today. An ~110kt upper level
jet will move east over ND and into MN. With mainly southwesterly
low level flow, temps look to climb into the upper 70s and low 80s
in the afternoon over the UP save for low to mid 70s in the east
near Lake Michigan with winds off the cooler lake. With minimal
capping noted in model soundings, some cu development is expected
late in the afternoon. Given the drier air noted in model soundings
and little synoptic support, storms will struggle to initiate in the
afternoon. That said, there is good model agreement in the scattered
showers and storms currently over western ND and northern MN moving
east to northern WI/Upper MI and Lake Superior for the latter part
of the afternoon. While some of these storms could be stronger with
bulk shear increasing to around 55kts and the 6/12 0Z HREF mean
MUCAPE building to 500-750 J/kg (highest over the far west), the
primary threat for strong to severe storms will come in the evening
as a second round develops in the MN Arrowhead.

&&

.LONG TERM /TONIGHT THROUGH TUESDAY/...
Issued at 553 AM EDT Wed Jun 12 2024

The extended period will immediately start out this evening in the
middle of a convective event as the first of two shortwaves
continues its progression across the region.  The question of
intensity, though, still remains the biggest challenge.  With decent
0-6 km shear values near 50 kts, thunderstorms will have a chance to
maintain some strong to severe potential.  But, the limiting factor
in the Thu 00-06Z time frame remains instability.  With MUCAPE
values in the 250-500 J/kg range and CIN values well below -50 J/kg,
storms will most likely diminish as they track across Upper Michigan
into tonight with just some rumbles of thunder and lingering rain
over the eastern third by Thu 09-12Z.

Thursday, after the early morning round of showers/thunderstorms, it
will generally be quiet through the morning. Nonetheless, strong
west-northwest winds will follow in the wake of the associated cold
front.  And, then a few showers/thunderstorms could develop again
during Thursday afternoon as the next shortwave provides a bit of
lift during the best diurnal heating of the day.  Severe weather
isn`t expected, but cannot entirely rule out a few strong ones with
some gusty winds and small hail.  The main impact Thursday will be
the winds outside of any storms, which will be strong as they mix
down behind the aforementioned cold front. Widespread 25 to 30 mph
winds are expected with isolated gusts in excess of 35+ mph per
GFS/ECMWF ensemble means.

After the winds diminish and rain tapers off Thursday evening, there
will be a period of benign weather through Saturday morning due to
ridging aloft. With the calmer weather will be slightly cooler, but
still above normal temperatures in the 70s before the start of
another warming trend through the weekend as guidance continues to
trend toward mid to upper 80s Monday through Wednesday.  Along with
the heat, though, will be multiple chances for showers and
thunderstorms starting Saturday morning as the next surface low
approaches from the southwest.  This low will track across the
region over the weekend quickly followed by a broad upper low.
Details with timing and strength remain low at this point, but
the main consensus is a trend toward another hot period with
active weather.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 144 PM EDT Wed Jun 12 2024

Main aviation concerns include timing and strength of potential
thunderstorms, potential for low clouds following the storms at CMX,
and low-level wind shear potential. There are two potential windows
for thunderstorms. The first is roughly 18-22Z at CMX and 20-24Z at
SAW. So far, no upstream convection is noted, and although modest
destabilization is occurring, potential for the first round is too
low to warrant inclusion in the TAFs. The second and more likely
round is roughly 01-04Z at CMX/IWD and 03-05Z at SAW. Storms in this
timeframe could produce strong wind gusts in excess of 40 kt as well
as large hail to around an inch at CMX/IWD. Storms will be weakening
with eastward extent but brief gusty winds and small hail still
could occur at SAW. Vsby could fall to IFR/MVFR in any storms. After
the storms, cloud bases will likely lower to MVFR/IFR late tonight
at CMX before rising/scattering by around 12Z Thu. Low-level wind
shear will be a concern at all sites tonight as a strong
southwesterly low level jet moves overhead. Outside of storms and
the period of possible low clouds at CMX, VFR conditions are
expected.

&&

.MARINE...
Issued at 454 AM EDT Wed Jun 12 2024

Southerly winds mainly 20 knots and lower will persist across Lake
Superior into this afternoon. But, as the high pressure is replaced
by a series of disturbances, an uptick in southerly winds of 20 to
25 knots can be expected late this afternoon. In addition, rain and
general thunderstorms will be possible across the far western
portions of the lake by late morning, overspreading the remainder of
the lake by this afternoon. Some storms could become strong to
severe, though, late this afternoon/evening mainly over the far
western portions of Lake Superior. Thursday, winds will become west-
northwesterly behind a cold front with 20 to 25 knots (isolated to
30 knots) outside of any additional thunderstorm chances through the
day. By Friday, winds will return to less than 20 knots with the
return of high pressure where they will stay until early Sunday
morning.

&&

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

&&

$$

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