436
FXUS63 KDLH 011731
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1231 PM CDT Tue Oct 1 2024

.KEY MESSAGES...

- Dry conditions will prevail through the next several days. Winds
  are forecast to weaken as humidities fall both today and
  Wednesday. While dry conditions persist, the fire weather
  conditions does`t appear as dangerous as previously forecast.

- Roller coaster of off and on fall-like temperatures through the
  week.

- A small chance of showers and perhaps a thunderstorm or two is
  forecast Saturday and Saturday night.

&&

.DISCUSSION...
Issued at 437 AM CDT Tue Oct 1 2024

Summary...

A progressive weather pattern continues today through early next
week with several areas of low pressure and alternating warm and
cold fronts propagating east across the Canadian Prairies and
Upper Midwest. Cooler temperatures are expected today as a
seasonal roller coaster of temperature changes begins. Gusty winds
this morning will gradually weaken through today. Winds turn
southerly with well-above normal temps expected for Wednesday.
Winds will be strong once again. Cooler again for Thursday and
Friday. Widespread frost is possible Friday morning. Then warming
again for Saturday. Cooler Sunday and Monday, then warmer again
Tuesday. Limited precipitation chances expected through the
period.

Today...

Cold air advection in the wake of yesterday`s cold front will
continue today. Surface high pressure centered over the western
South Dakota/Nebraska border will drift generally eastward today.
An area of high clouds over western portions of the Canadian
Prairies, North Dakota, and eastern Montana will stream eastward
and pass over the Northland today. Strong and gusty west and
northwest winds early this morning will gradually weaken today. I
raised temperatures a few degrees early this morning as the strong
winds were keeping the boundary layer mixed. From that warmer
start, it seemed reasonable to nudge high temps today a few
degrees warmer, too. Expect highs from the upper 50s near the tip
of the Arrowhead to the middle and upper 60s in central Minnesota,
the I-35 corridor, and portions of northwest Wisconsin.

Fire weather conditions didn`t materialize as expected yesterday
and thus concerns about fire weather conditions today have relaxed
ever so slightly. Minimum RH values upstream over Saskatchewan,
Alberta, and Montana yesterday were in the upper 20 to low 30
percent range. Think that trend toward slightly moister conditions
will continue into the Northland. Raised dewpoints and RH values
for today to account for that trend. With wind speeds and gusts
decreasing during the day, and afternoon RH values not as dry as
previously expected, near- critical fire weather conditions appear
less likely.

Tonight through Wednesday night...

The area of surface high pressure will drift to near Saint Louis,
MO by early Wednesday morning while a weak area of low pressure
and another cold front slide eastward across the Canadian Prairies
and northern Plains. The pressure gradient will tighten over the
Upper Midwest tonight and wind speeds are expected to increase and
become gusty again. Winds will turn southwesterly and southerly
overnight. Raised minimum temps tonight as well do to the
persistent mixing, starting with 75th percentile of the NBM
guidance and then narrowed the temperature range by nudging the
warmer values a few degrees cooler. This yielded lows from around
40 for the interior Arrowhead and portions of northwest Wisconsin
to the middle and upper 40s over central and north-central
Minnesota.

The southerly winds will bring in warmer temperatures for
Wednesday. Much above normal temperatures in the middle 60s to
middle 70s are forecast. Winds will gradually weaken during the
day while RHs fall. The mismatch of timing may avoid near-
critical fire weather conditions once again.

The low pressure system and cold front will push through the
region Wednesday night and early Thursday morning. Look for lows
in the upper 30s to low 40s, except along the South Shore where
upper 40s and low 50s are possible.

Thursday through early next week...

Thursday and Friday are shaping up cooler, though still on the
warmer side of normal. Widespread frost is possible if winds can
taper off early Friday morning.

The progressive pattern will continue heading into the weekend
with another area of low pressure taking aim on the region.
Temperatures should trend well above normal for Saturday and then
cooler again for Sunday and Monday. There`s a small chance of
showers and perhaps thunderstorm or two with the system Saturday
afternoon through Saturday night. Another warmer period is on the
horizon for Tuesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1215 PM CDT Tue Oct 1 2024

VFR conditions expected for the TAF period. Gusty winds will
continue through the day along with increasing coverage of
diurnal cumulus with bases at around 5kft. Tonight, strong
southerly flow aloft could lead to some LLWS in the early
morning hours when winds are expected to be at their lowest.
LLWS should clear Wednesday morning as surface winds increase.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 437 AM CDT Tue Oct 1 2024

Strong and gusty west and northwest winds early this morning
will gradually subside with time today. Look for winds of 10 to
20 knots with gusts of 20 to 28 knots by 15Z. Winds will
continue to weaken to 5 to 15 knots with gusts of 10 to 20 knots
by 00Z Wednesday. Small Craft Advisories remain in effect and
will expire as conditions improve this afternoon and early
evening.

Winds will gradually back southwesterly in response to an
approaching low pressure system and cold front. Wind speeds and
gusts will increase once again this evening and overnight.
Southwest winds of 20 to 28 knots with gusts of 25 to 40 knots
Wednesday morning. Gales are forecast Wednesday for much of the
south shore waters, from Port Wing to Saxon Harbor, and from
Grand Marais to Grand Portage along the north shore. Small Craft
Advisories will likely be needed leading into the gales and for
the areas not included in the Gale Watch.

The low pressure system will pass just north of Lake Superior
Wednesday night with a cold front expected to advance eastward
over the waters by early Thursday morning. Winds will veer
northwesterly and weaken Wednesday night behind the front.
Hazardous winds and waves return Saturday and Sunday.

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 until 8 PM CDT this evening for LSZ121-
     140-146>148-150.
     Gale Watch from Wednesday morning through Wednesday afternoon
     for LSZ121-146>148-150.
     Gale Watch from Wednesday morning through Wednesday evening
     for LSZ140.
     Small Craft Advisory until 6 PM CDT this evening for
     LSZ141>143.
     Small Craft Advisory until 5 PM CDT this afternoon for LSZ144-
     145.

&&

$$

DISCUSSION...Huyck
AVIATION...KML
MARINE...Huyck