103
FXUS63 KDLH 050551
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1251 AM CDT Sat Oct 5 2024

.KEY MESSAGES...

- Gusty winds and near-critical fire weather Saturday morning.

- Showers Saturday afternoon areawide with isolated thunderstorms
  in northwest Wisconsin into the early evening. A cold front
  brings colder weather and more gusty winds Sunday.

- Dry weather continues next week.

&&

.DISCUSSION...
Issued at 244 PM CDT Fri Oct 4 2024

This Afternoon:
Mostly sunny skies out there this afternoon with some high
cirrus and a bit of cumulus over the Arrowhead. Not
surprisingly, we have dried out with relative humidity as low as
~20% for a few places and around 25-30% for most. Fire weather
conditions remain elevated this afternoon, but not as bad as
they could be since wind gusts are generally around or less than
20 mph.

Tonight through Saturday Night:
Ahead of a low pressure system skirting just north of the
Canadian border and heading east towards the region on Saturday,
strong southerly flow and a low-level jet will develop tonight.
Wind speeds will gradually increase overnight, and we will have
a bit of increasing low-level moisture as well, so a few clouds
will be possible Saturday morning. As a cold front pushes
through from west to east mid-day Saturday into early Saturday
night, expect increasing clouds and rain chances. There remain a
few timing differences among CAMs, but generally there is
agreement on showers developing around the Arrowhead into
northwest Wisconsin Saturday afternoon, tapping into some
diurnal instability, and quickly moving east into the evening.
There will be a short window where a few thunderstorms will be
possible. With plenty of shear aloft, an isolated strong to
severe storm can`t be completely ruled out. Strong winds will be
the main threat, but can`t rule out a little hail up to quarter
size too. Overall, the threat for severe weather is small, only
about 2-5%. Rainfall is not expected to be significant, though
we could use it. Totals to around a quarter of an inch where
thunderstorms develop and lesser amounts elsewhere.

The other concern for Saturday will be the potential for near-
critical fire weather conditions, which will be most likely for
the north-central part of Minnesota. This is where rain chances
are expected to be slim to none and there`s a higher potential
for relative humidity to fall to 30-40%. Strong southerly winds
regionwide gusting to 30-35 mph, locally up to 40 mph, will be
the primary contributor to near-critical fire weather
conditions. The current expectation is that areas further east
will see clouds and rain developing Saturday afternoon, which
should lead to some improvement of relative humidity and tamper
fire weather conditions.

Sunday:
As the cold front passes through Saturday night, winds will
gradually shift northwesterly going into Sunday. There may be a
little wraparound rain showers, but nothing that will amount to
any appreciable accumulation. Temperatures cool down with highs
in the 50s to 60s. We may have a continuation of near-critical
fire weather conditions as winds remain in that 30-35 mph area
for gusts from the northwest, and min RH falls into the 30-50%
range for most places.

Monday through Friday:
Ridging develops across the western CONUS, and as such, we will
continue the pattern we have been seeing the past month or so
with mild, dry weather without rain chances. Fortunately, there
are no major signals for very breezy days, but nevertheless,
fire weather conditions will likely remain elevated with the
continuing dry weather.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1250 AM CDT Sat Oct 5 2024

An energetic fall system will bring another round of strong
gusty winds and LLWS to the area for this TAF period. South to
southeast surface winds as of issuance time will slowly
strengthen overnight, with even stronger southerly winds of 40
to 50 knots aloft which will produce LLWS at all the terminals,
mostly in the 08z-16z time range. After 16z surface winds
strengthen to around 15 knots with gusts around 30 knots. A cold
front will move through the terminals beginning in the early
afternoon, causing winds to veer into the west and temporarily
weaken, then increase once again into the 10-15 knot range with
gusts of 20-25 knots. Some showers and even isolated
thunderstorms are possible along the front, but have stuck to
VCSH groups for now.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 1004 PM CDT Fri Oct 4 2024

Winds further increase across the western waters overnight
ahead of an incoming low pressure. Strong south to southeast
winds Saturday create a day of widespread conditions hazardous
to small craft. Gale force gusts are most likely Saturday
offshore of Grand Marais so a Gale Warning starts Saturday late
morning for that zone. As the cold front passes over the lake
Saturday evening, winds shift westerly Saturday night. Behind
the front late Saturday night, the winds increase from the west-
northwest to reach gale-force areawide for early Sunday morning
and lasting into early Sunday night. A few thunderstorms are
possible (10% chance) over the South Shore nearshore waters
Saturday late afternoon.

For the open water discussion, refer to the NWS Marquette Area
Forecast Discussion at weather.gov/mqt.

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory from 4 AM early this morning to 1 AM CDT
     Sunday for LSZ121-141>148-150.
     Gale Warning from 1 AM to 10 PM CDT Sunday for LSZ121-141>148-
     150.
     Small Craft Advisory from 4 AM to 10 AM CDT this morning for
     LSZ140.
     Gale Warning from 10 AM this morning to 10 PM CDT Sunday for
     LSZ140.

&&

$$

DISCUSSION...JDS
AVIATION...LE
MARINE...NLy