954
FXUS63 KMQT 070730
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
330 AM EDT Fri Jun 7 2024

.KEY MESSAGES...

- Showery weather and much cooler through the weekend under the influence
  of low pressure, then warming and drying early next week.
- Wind gusts to 30 mph and pea-sized hail could be seen in a few
  of the thunderstorms Saturday.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 229 PM EDT Thu Jun 6 2024

RAP analysis shows a vertically stacked trough over much of northern
Ontario that continues to send shortwave impulses through the Upper
Midwest and Upper Great Lakes region. This is the forcing for the
showers and occasional thunderstorms evident on radar returns. Most
of these storms have gone up and come back down in just a handful of
radar scans, but a few of them have had vigorous enough updrafts to
produce gusty winds (peak so far as of 18Z is a gust of 32 kt at
KESC) and pea sized hail. The outlook for these storms is fairly low
as peak SBCAPE in the 12Z HREF is only around 500 J/kg and not much
shear to work with. Precipitation rates are also not expected to be
extreme as HREF mean total precip by 12Z Friday is only around a
tenth to a half of inch.

With cool, northwesterly flow aloft, temperatures are once again
cooler day-over-day, with highs only in the 60s and upper 50s today
and lows in the 40s to low 50s. Mixing is allowing a 30-35 kt jet at
950mb to mix towards the surface, leading to gusty W and NW winds at
the surface through tonight. As troughing weakens and shift
northeast, expect a drying trend overnight with regards to
precipitation, though broken to overcast skies will prevail through
at least 12Z Friday.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 329 AM EDT Fri Jun 7 2024

The shortwave low action continues through this weekend as a
troughing pattern set up over central Canada tonight makes its way
east to the St. Lawrence Seaway by Sunday evening. Meanwhile, high
pressure ridging over the Northern Rockies and in the Northwest
Territories tonight drops down to the Canadian Prairies and Northern
Plains by Monday morning, bringing with it a reprieve from the
rainfall for early next week. As the high pressure ridge continues
to dig through the Great Lakes region towards New England while
weakening through the middle of next week, expect a cold front to
bring back rain chances back across our area Tuesday and/or
Wednesday night and Thursday. Well above normal temperatures look to
dominate the middle to latter portions of next week as warm air
advection from the Desert Southwest is projected to travel over our
area. More details follow below.

We start the extended period dry for a little while as skies look to
be mostly clear through midnight tonight. This will allow
temperatures to drop down into the mid to low 40s in the central and
east tonight as cloud cover looks to be limited/not make it to those
areas until near/after dawn. That being said, rain showers look to
return to the western U.P. late tonight as yet another shortwave
rotates down from southern Manitoba through the U.P. Saturday. As
the showers move into the eastern half of the U.P. by the mid-
morning, we could see a few thunderstorms develop over the interior
areas as CAPE becomes surface based to a few hundred J/kg. However,
with little shear to work with within the convective profile of the
atmosphere, no severe weather is expected; while shearing picks up
significantly in the upper levels of the atmosphere, looking at the
model soundings shows that parcel uplift is likely (70+%) to not
reach these much higher winds. That being said, we could see some
wind gusts up to 30 mph and pea-sized hail from a couple of these
thunderstorms due to updraft collapse. Don`t expect another breezy
day Saturday, as limited temperature advection, a somewhat
lackluster pressure gradient, and mostly cloudy skies will keep
winds fairly light across the area; the exception could be in the
Keweenaw in the hills to the south and north of Houghton, where
winds could gust up to 25 mph during the mid to late afternoon
hours. Overall, expect the highs Saturday to be pretty similar to
what we will see today, namely the 60s. The showers look to end
Saturday night as the shortwave continues to distance itself from
us.

Don`t expect the reprieve from the rain showers to last all that
long though, as one final shortwave rotates over our area come
Sunday. With flow becoming more northerly, expect temperatures over
the north half Sunday to be a few degrees cooler than what`s
expected Saturday; meanwhile, temperatures look to be a few degrees
warmer in the south central on Sunday. The last of the showers looks
to leave our area Sunday evening as high pressure begins to finally
build into our area...

We finally get an extended period of drier weather come Monday as a
high pressure drops from Canada over the Upper Great Lakes. Expect
sunny skies and light northerly flow as the high pressure continues
to dig into the rest of the Great Lakes region Monday into Tuesday.
The current forecast from the NBM has RHs dropping down into the
lower 30 percents during the afternoon hours Monday. While the
recent rainfall will help to keep surface moisture a little higher,
given the dry air from the high moving overhead and the sunny skies,
I wonder if we will see RHs drop down into the 20 percents or lower
come Monday; as for right now, the uncertainty on this happening is
a little too high to make any changes to the current forecast.

We could see the dry weather come to an end Tuesday as the cold
front of a low could move through the area. However, there has been
recently been some model diffluence on where the low will appear;
should the low fire out from northern Alberta, then we will more
than likely remain dry into the middle of next week. Likewise,
should the southerly solutions on the placement of the low win-out,
then the chances for rainfall will become much higher.

As we continue through next week, expect the temperatures to
progressively warm with each day until near the end of next week,
when there is very little model agreement. It does appear that
another cold front will move through around next Wednesday too,
bringing more showers and storms across the U.P. However, zonal flow
is expected behind it in the mid levels, with warm air advection from
the Desert Southwest possibly continuing behind it.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 109 AM EDT Fri Jun 7 2024

A nearly stationary low pressure over Ontario results in a steady
flow of marginally MVFR/VFR cigs across our 3 TAF sites. Cigs at
IWD/CMX have been VFR for several hours now and favor VFR prevailing
at IWD, but observations lowered to MVFR at SAW and are trending in
a similar direction at CMX. Model guidance adds confidence to the
lowering trend at CMX tonight until surface heating increases mixing
on Friday. All sites improve to VFR on Friday, but timing
differences exist between the various models. Tend to favor faster
dissipation on GFS as compared to CAMs. Otherwise, breezy WNW winds
continue at all terminals through Friday, but gustiness was left out
of TAFs at time.

&&

.MARINE...
Issued at 329 AM EDT Fri Jun 7 2024

Some westerly gusts of 20 to 25 knots are expected across the lake
today as a shortwave low pressure moves through the Upper Great
Lakes this morning and traverses into the Lower Great Lakes by this
evening. Once the winds die down to 20 knots or less this evening,
expect the light winds to continue across the lake until the end of
the forecast period as weak shortwaves continue this weekend
followed by high pressure ridging early next week.

We could see some thunderstorms along the lakeshore Saturday as
another shortwave rolls through the area. While no severe weather is
expected, we could possibly see gusts up to 30 mph and small pea-
sized hail due to updraft collapse.

&&

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

&&

$$

SHORT TERM...GS
LONG TERM...TAP
AVIATION...EK
MARINE...TAP