449
FXUS63 KDLH 270737
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
237 AM CDT Fri Sep 27 2024

.KEY MESSAGES...

- Unseasonable warmth and dry conditions continue through the
  weekend. Near record high temperatures forecast for some
  locations today and Saturday.

- Pattern change arrives Monday with a cold front that will
  usher in much cooler air along with a low chance (10-30%) for
  showers, mainly across our north.

- Near to slightly below normal temperatures take over starting
  Tuesday with a 30-50% chance for patchy frost Monday night and
  more widespread frost (60-80% chance) Tuesday night.

&&

.DISCUSSION...
Issued at 236 AM CDT Fri Sep 27 2024

Current Conditions - Today:

High pressure located across the Great Lakes up into far
southern Hudson Bay has resulted in persistent clear skies and
calm to light winds across much of the area this morning. This
is leading to pockets of ground fog, some locally dense, in the
Northland that should dissipate within an hour or two after
sunrise this morning.

Winds continue to remain light today, shifting to northwesterly
by this afternoon as a dry cold front slides through the area.
850 mb and 925 mb temperatures of 15-17 degC and 18-21 degC,
respectively, will be near the maximum of sounding climatology,
leading to another unusually warm day for late September under
plenty of sunshine. High temperatures will range from the upper
70s near International Falls and areas near Lake Superior to
low to mid-80s across the remainder of the Northland. Some of
the warmest locations could approach record high temperatures
for September 27th.

This Weekend:

Broad mid/upper-level ridging and 850mb/925mb temperatures
remaining near the maximum of sounding climatology will keep
dry, sunny, and very warm conditions persisting through this
weekend. Widespread high temperatures in the low to mid 80s are
expected for Saturday. Widespread 70s to around 80 degrees are
expected for areas away from Lake Superior as onshore flow from
Lake Superior on Sunday will knock temperatures down a few
degrees.

Monday - Tuesday:

We see the weather pattern begin to shift starting on Monday as
a shortwave trough cuts east from the high Plains/Canadian
Prairies on Monday and into the Northland vicinity late Monday
into Monday night. This system will also bring a cold front
through the Northland, while the surface low pressure and better
synoptic forcing remains farther north in central Manitoba to
far northwest Ontario during this timeframe. Forecast rainfall
amounts remain very fleeting, with rain shower chances only
around 10-30%, primarily north of the Iron Range. Some portions
of the South Shore could also see some light rain Monday night
into Tuesday as temperature differences of 14-16 degC between
850mb and the surface of Lake Superior help drive lake-effect
rain showers. Cold-air advection lighter rain chances (10-30%)
continue into daytime Tuesday for areas north of the Iron Range,
with very little in the way of accumulating precipitation.

Temperatures on Monday will still be warm ahead of the cold
front, with highs in the mid 70s to around 80 degrees. However,
look for lows to drop into the mid 30s to low 40s Monday night
behind the front, with the coolest of these temperatures in
northeast MN. Tuesday will feel more like fall with highs in
the mid 50s to low 60s, and widespread Tuesday night
temperatures in the low to mid-30s. The probability of a
widespread frost Tuesday night into early Wednesday is 60-80%
and has been increasing over the last several forecast runs.
Some parts of the Iron Range and inland Cook County could also
touch below freezing temperatures.

Rest of Next Week:

Fall temperatures and mainly dry weather continue through the
remainder of next week with high temperatures in the upper 50s
to mid/upper 60s, or around to slightly below average for early
October and nightly lows in the 30s to 40s. There is not much of
a signal for any organized weather systems the remainder of
next week, so have kept a predominately dry trend of weather
(precip chances <20%) going for mid to late next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1248 AM CDT Fri Sep 27 2024

There is some patchy ground fog, locally dense at times,
expected through the current overnight hours into early this
morning. The best signal is at KHIB and KHYR, and have inserted
MVFR visibilities into KHYR and some periods of MVFR to LIFR
visibilities at KHIB. Otherwise, plenty of sunshine and VFR
conditions today with winds starting out calm and then turning
light out of the southwest early today and then veering to
northwesterly/northerly behind a passing dry cold front today.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 236 AM CDT Fri Sep 27 2024

Winds will remain generally under 10 knots out of the southwest
this morning into mid-afternoon before veering to out of the
north and remaining light late this afternoon into tonight.
Grand Marais to Grand Portage could see a few gusts reach 15
knots during the late morning and afternoon. High pressure
returns to the area for the weekend, with variable light winds
on Saturday. Northeast winds of 10-15 knots with gusts of 15-20
knots late Sunday morning into 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...None.

&&

$$

DISCUSSION...Rothstein
AVIATION...Rothstein
MARINE...Rothstein