000
FXUS63 KMQT 180817
AFDMQT

Area Forecast Discussion
National Weather Service Marquette MI
417 AM EDT Thu Apr 18 2024

.KEY MESSAGES...

-Cooler temps Friday and Saturday with low (30%) chances for
 light rain showers this afternoon/evening and perhaps a light
 lake effect rain/snow mix for Friday/Saturday.
-Localized fire wx concerns could resurface again Friday into
 Saturday with more widespread concerns emerging by Sunday and
 Monday as a drier airmass moves in with breezy W to NW winds.

&&

.SHORT TERM /THROUGH THIS AFTERNOON/...
Issued at 259 AM EDT Thu Apr 18 2024

GOES-16 Channel 10 Water Vapor imagery shows the stacked low
pressure that has driven rainfall over the last day or so over the
Upper Peninsula. That feature, now at 1006 mb and weakening, will
exit the eastern end of Lake Superior throughout the morning,
leaving surface pressure rises and shortwave ridging aloft in its
wake. However, any clearing behind the low`s departure will be brief
as wraparound moisture from the low will help clouds linger as well
as clouds streaming northeast from a shortwave trough exiting the
Central Plains. The broad trough associated with this shortwave is
based over the Canadian Prairie this morning and that trough will
shift east today, sending various rounds of PVA towards the UP
today. A few light rain showers are the result, with the 00Z HREF
showing the chance of measurable rain ranging from 30-70% mainly in
the central UP bounded to the west by Baraga and to the east by
Manistique. Hourly PoPs are a bit harder to nail down as each
ensemble member resolves the light showers slightly differently, but
the highest chances for any given hour seem to be mainly in the
Menominee area at 15-20% prior to 21Z before overspreading the rest
of the central UP (20-40%) from 21Z-00Z this evening. The absolute
maximum rainfall totals prior to 00Z in the HREF look to be around
0.2 inches, with ensemble means at only a couple hundredths, so
impacts should be minimal. A slackening pressure gradient will make
for lighter winds today, with a few hi res models even showing a
brief lake breeze off of Lake Superior, though not penetrating far
inland. Patchy fog has been observed in the wake of the low with
METARs from CMX varying wildly between 1/4SM and 4SM visibility
much of the night already. The fog will likely be gone after
sunrise as by 12Z this morning, HREF probability of visibility
1/2SM or less is only 20% on the upslope areas of the Keweenaw
Peninsula.

&&

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
Issued at 347 AM EDT Thu Apr 18 2024

The extended period is looking to be fairly calm, although we could
see some showers tonight, Friday into Saturday, and early next week.
Drier lower levels Friday through this weekend into early next week
could lead to some fire weather concerns, particularly Sunday when
min RHs get down into the mid 20 percents. Overall, temps are
looking to be around normal to above normal, but tonight through
Saturday are looking to be below normal. Additional details on the
forecast follow below.

The last of the rain showers associated with the shortwave low
moving through the Midwest into southern Ontario tonight
progressively end over the eastern U.P.. Meanwhile, a cold front
from a low over northern Ontario continues eastwards across our area
tonight. As the cooler and drier air behind the front works its way
across the U.P., the cloud cover decreases. This will allow temps to
drop down into the low to mid 30s across the interior areas of the
U.P. tonight; we even have a 20 to 30% chance of seeing lows drop
into the upper 20s across the interior west. As delta-Ts get to
around 12C by dawn Friday, expect to see some lake-effect cloud
cover developing over the WNW snow belts from west to east. With the
help of some upslope enhancement, we could (30 to 50% chance) see
some light lake-effect/diurnally forced snow showers across the WNW
snow belts, mainly in the higher terrain areas of the interior west;
the eastern U.P.`s WNW snow belts may have more of a rain/snow mix
or just light rain. As the cold air advection continues behind the
front Friday night, the light showers continue across the WNW snow
belts. As ridging and warmer air begin to move in Saturday, the
showers end. Ultimately, nothing more than a light dusting is
expected from any snowfall. Drier conditions are expected from
Saturday afternoon to next Monday.

While we could see some light rain and snow showers Friday to
Saturday, model guidance is really hinting at some dry air near the
surface those two days in addition to Sunday and next Monday too.
This brings up some fire weather concerns as we head into this
weekend into early next week. For Friday, we have W to WNW`rly winds
gusting up to 30 mph across the area and possibly up to 40-45 mph
near the shore of the Keweenaw; the saving grace for Friday, though,
is that min RHs are looking to only bottom out to the low 30
percents in Menominee County and the highs are only projected to be
in the 40s. Saturday is looking to be pretty similar, save for it
being drier across the interior west (min RHs near 30 percent)
during the afternoon hours. On these two days, we could see some
very limited/localized elevated fire weather concerns. However, come
Sunday and possibly Monday expect even drier conditions; with breezy
NW`rly winds, min RHs down to the mid 20 percents, and highs in the
50s, there`s a good (70+%) chance that we see some elevated fire
weather concerns come Sunday. Monday appears similar too, although
the winds appear weaker and the temperatures warmer (in the mid 50s
to low 60s). Therefore, fire weather partners should keep an eye on
future forecast packages, as any changes in the temps, RHs, and
winds could influence the fire weather concerns this weekend through
early next week...

Our next chance for precip looks to come around the Monday
night/Tuesday time period. While the NBM brings 50 to 60% chances
for precip across the area during this time period, I`m thinking the
actual chances should be lower (30 to 50% instead) as the latest GFS
and European guidance tracks the associated shortwave low too far
south now to bring anything over us. Should we remain dry, we could
see elevated fire weather concerns return towards the end of next
week.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 127 AM EDT Thu Apr 18 2024

As the low lifts northeast from Lake Superior into Ontario early
this morning, expect a general trend towards improving conditions,
even though the TAF sites are currently MVFR/IFR/LIFR due to
low-level clouds and patchy fog. The conditions across the TAF
sites look to improve to VFR by late this morning as drier air
moves into the region behind the low. A shortwave low moving
from the Plains into the Midwest today could bring some light
rain showers back over KSAW this afternoon and evening; that
being said, KSAW looks to remain VFR this afternoon and evening.

&&

.MARINE...
Issued at 417 AM EDT Thu Apr 18 2024

WNW winds of 20 to 25 knots over the eastern lake this morning
weaken to 20 knots or less by noon, before SW winds of 20 to 25
knots pick up over the western half of the lake this afternoon. As
the winds over the western lake slowly veer more towards the W
tonight, the winds increase to 20 to 30 knots. The winds continue
increasing to gales up to 35 knots over the central lake along the
northern shore of the Keweenaw Friday via funneling along the
shoreline and cold air advection continuing across the area behind a
cold front. As the winds veer more towards the NW Friday night into
Saturday, the winds weaken to 20 to 30 knots across the lake before
backing to the SW over the central lake early Saturday evening. As
we get clipped by a cold front Saturday night into Sunday, W winds
of 20 to 30 knots continue across the waters of Lake Superior. As
ridging builds in Sunday night, winds die down to 20 knots or less
and remain that way until possibly Monday night, when a shortwave
low moving through the Upper Midwest increases N`rly winds to 20 to
25 knots across the lake through Tuesday night.

&&

.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
  Small Craft Advisory until 8 AM EDT this morning for
     LSZ244>248.

  Small Craft Advisory until 10 AM EDT this morning for LSZ249.

  Small Craft Advisory until noon EDT today for LSZ250.

  Small Craft Advisory until 2 PM EDT this afternoon for LSZ251.

Lake Michigan...
None.

&&

$$

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