955
FXUS63 KMQT 081942
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
242 PM EST Fri Nov 8 2024

.KEY MESSAGES...

- Dry weather weather through Saturday with above normal
  temperatures, then rain returns Saturday night and Sunday.

- Blustery west to northwest winds on Monday, especially over
  the Keweenaw and eastern Lake Superior shoreline areas where
  gusts of 40-45 mph are possible.

- Next chance for widespread precipitation possible
  Wednesday/Thursday, but uncertainty on specifics is high

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 242 PM EST Fri Nov 8 2024

Water vapor imagery and RAP analysis show mid-level ridging over the
Northern Rockies into Alberta/Saskatchewan/Manitoba with downstream
trof over se Canada and the ne U.S. A cutoff low is centered over
NM. At the sfc, upstream ridge is supporting building high pres over
the Upper Mississippi Valley. After rapid development of stratocu
this morning, mainly across n central and eastern Upper MI, incoming
dry air mass has eroded much of those clouds this aftn. However, air
mass is cold enough over eastern Lake Superior (850mb temp around
-4C per latest RAP analysis) for some lake stratocu to develop
over the lake and stream into eastern Upper MI. Current temps are in
the mid 40s to lwr 50s, but as high as the mid 50s F far s central.
So, about 5-10 degrees above normal for this time of year.

With sfc high pres ridge moving across the fcst area during the
evening, the evening will be quiet with winds diminishing to
calm/near calm. Sct-bkn stratocu will continue to stream into the
eastern fcst area this evening until arrival/passage of high pres.
Otherwise, clear skies will prevail tonight. Expect min temps from
the low/mid 20s in the interior, coldest e, to the low/mid 30s F
along portions of the Great Lakes.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 344 AM EST Fri Nov 8 2024

Surface and upper-level ridging will continue to dominate the
region, keeping Upper Michigan dry through Saturday with above
normal temperatures expected on Saturday in the upper 40s and lower
50s.

By Saturday night into Sunday, the focus shifts to a closed low now
over the desert Southwest which will be poised to lift through the
Central Plains on Saturday and into the Upper Great Lakes later this
weekend, bringing our next shot of rain late Saturday night into
Sunday evening. Models still not in great agreement on the sfc low
track into the Upper Great Lakes on Sunday but guidance suggests any
rainfall will be light, generally in the .1 to .2 inch range based
on ensemble probability QPF fields, highest south central and east
along the most probable sfc low track.

After a brief period of ridging and drying on Sunday night, a
Clipper shortwave moving through northern Ontario and associated CAA
behind it under a gusty nw wind flow into the Upper Great Lakes
should initiate some light showers across the area on Monday,
especially into northwest and eastern portions of the U.P. on
Monday. With 850 mb temps expected to dip as low as -7C and Lake
Superior sfc temps 9-10C, expect the overwater instability to
generate some lake effect rain/snow showers Monday afternoon/evening
especially in the far east, although coverage of lake effect showers
will likely be offset by dry low levels as noted by inverted-V look
to fcst soundings. Increased mixing from the unstable conditions
will allow west to northwest winds to gust perhaps as high as 40-45
mph across the Keweenaw and eastern shoreline areas on Monday.
Ridging and continued subsidence building in from the west behind
the shortwave should quickly end any remaining lake effect pcpn by
late evening Monday. Highs on Monday will quickly range from the mid
40s northwest to the lower 50s south and east.

After a period of drier conditions under ridging on Tuesday, our
attention then turns to a shortwave/frontal boundary moving through
the region in the Wednesday/Thursday time frame. Model agreement on
forecast details at this time is poor with this midweek system,
lending great uncertainty to the forecast details. Deterministic
models and ensemble members offer a wide range of solutions and
spread with perhaps the GFS/GEFS hinting at a deeper solution than
the ECMWF/EPS. Given the great uncertainty, for now will stick
closer to the model blend on pops and temps at this time.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1240 PM EST Fri Nov 8 2024

High pres approaching from the w will move across the Upper Great
Lakes tonight. Associated dry air mass will allow VFR to prevail at
IWD/CMX/SAW thru this fcst period. NW to N winds around 10kt, but
gusting to near 20kt at SAW, will diminish to light under 5kt late
aftn/early evening as the high arrives. S winds will set in
overnight, but will remain under 10kt thru Sat morning.

&&

.MARINE...
Issued at 344 AM EST Fri Nov 8 2024

After westerly gales of 35 to 40 kts end around sunrise over the
east half of Lake Superior, winds then veer northwest 15-30 kts by
late morning (highest east half) and then weaken to 20 kts or less
late in the day as surface high pressure builds in from the west.
Winds will remain light, less than 20 kts, into tonight.

As the surface high pushes east of the Upper Great Lakes on Saturday
a surface low will gradually be lifting north through the Central
Plains. This will result in southerly winds increasing to 20-25
knots on Saturday, highest north and east half. The Plains low will
eventually reach northern Lake Michigan on Sunday at 29.6 inches as
winds become light, generally less than 20 kts late Saturday night
into Sunday evening. A deeper low pressure of 29.3 inches moving
east through northern Ontario will bring a front and associated shot
of cold air across Lake Superior on Monday. The unstable conditions
will cause gusty west to northwest gales to develop Monday into
Monday evening with model ensemble probability showing a high
potential for at least low-end gales (70-90%) across central and
eastern Lake Superior.

Ridging builds in quickly Monday night as winds fall below 20kts
Monday night into Tuesday morning, but as the high pushes east
southerly winds will ramp up to 25 to 30 kts late Tuesday with EPS
ensemble probability showing a 30-50% chance of low-end gales
Tuesday night into Wednesday over northern and eastern sections of
the lake ahead of another approaching frontal system during the
midweek period.

&&

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

&&

$$

SHORT TERM...Rolfson
LONG TERM...Voss
AVIATION...Rolfson
MARINE...Voss