535
FXUS63 KDLH 011735
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1235 PM CDT Sat Jun 1 2024

.KEY MESSAGES...

- Isolated thunderstorms may occur this afternoon in the
  Arrowhead and into northwest Wisconsin.

- Warm temps for Sunday with the potential for severe weather.
  Some storms will be possible in the afternoon but the best
  chances will arrive in the late evening and overnight hours as
  a line of storms moves west to east.

- Very active weather pattern through next week with potential
  for severe storms returning Tuesday afternoon.

&&

.DISCUSSION...
Issued at 407 AM CDT Sat Jun 1 2024

Current conditions:

A stalled out boundary draped over NW WI continues to bring
some light rain showers across the area this morning. This
boundary will loiter through the day giving way to persistent
precipitation chances. The past 24 hr precipitation totals
across NW WI are around .3 to .5 inches as of 1AM. These
additional PoPs will garner another .2 to .4 inches with most
the area staying shy of 1 inch. The river gauges in the area
show no strong responses at this time so flooding concerns
remain low. However, some ponding can be expected in low lying
areas.

Back over in northern MN an upper level shortwave pushes across the
Northern Plains with a weak cold front at the surface. With diurnal
cumulus and some lift from this boundary we could see some very
brief and light showers and embedded thunderstorms. However,
low levels remain very dry and CAMs are not in the strongest
agreement, so we have kept PoPs around 20-30%.

Sunday:

Surface high pressure will be exiting to the east during the morning
hours with a surge of southerly winds streaming in before noon. The
first half of the day will be quiet with high temps soaring into the
upper 70s and low 80s. Some isolated storms may begin to populate in
the afternoon, but the main show looks to be Sunday evening into
Monday morning.

A shortwave ejecting out of the Intermountain West will lead to
cyclogenesis in the Dakota`s. This low is expected to propagate
across the Upper Midwest with it`s attendant cold front being
the focal point for severe weather. Severe storms will initiate
over the Northern Plains and sweep into north central MN in the
evening and overnight hours. The mean wind vectors along the
frontal boundary suggest the potential for a QLCS set up. The
main question for our area will be how far will this line of
storms be able to penetrate before running into more stable air.
As mentioned previously, good southerly flow and moisture
advection through the day will see above normal temps and
dewpoints in the upper 50s. MUCAPE values of 300-500 J/kg are
progged by the deterministic models with bulk shear of 35-40kts.
The NCAR ensemble depicts the line of convection pushing
through MN and weakening as it moves into NW WI by the early
morning hours. Which looking at mid level lapse rates matches
pretty well. Depending on the arrival time the severe threats
will vary. The primary threat will be damaging winds but some
hail and a possible tornado along our western CWA can`t be ruled
out. One additional threat to be aware of is the potential for
some flash flooding. Soil saturation is very moist and
forecasted rainfall with this system is between 1" to 1.5" For
now, SPC has our western counties in a slight risk (2 out of 5)
and a marginal risk ( 1 out of 5) for most of our other
counties.

Monday into midweek:

Rain showers and a few storms continue to start the work week as a
strong low level jet continues to supply the region with a gulf
connection. The aforementioned cold front will push out of the
area in the evening hours allowing for a brief reprieve in the
action.

The active pattern continues with Tuesday sporting another system
moving across the region. The upper level jet digs down into the
Central Plains with the parent low telegraphed to be in the
Canadian Prairies. This would lead to the warm sector setting
up over the Northland and another potential severe weather day.

Cluster analysis highlights ridging building over the Pacific
Northwest and an upper level low stalling over the Great Lakes
region. This will lead to persistent PoPs and active weather
through the remainder of the week.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1232 PM CDT Sat Jun 1 2024

Breezy west winds through 00Z Sunday become light and variable
backing southerly 12-15Z Sunday. Mist resulting from overnight
marine fog off Lake Superior may (30% chance) drop visibility
at terminals along and right near the shorelines, including DLH.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 832 AM CDT Sat Jun 1 2024

A stalled frontal boundary creating light to moderate rainfall
over the lake last night into this morning has created lingering
dense fog, with Dense Fog Advisories now in effect. Fog is
likely to clear from southwest (Twin Ports and South Shore late
morning to early afternoon) to northeast (last near Grand
Portage late this evening) today. Some model guidance even keeps
marine fog though from Taconite Harbor northward into the
overnight hours so extensions in time of the current far
northern North Shore Advisory may be needed this evening. Winds
remain at or below 15 knots today 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...Dense Fog Advisory until 10 PM CDT this evening for LSZ140-141.
     Dense Fog Advisory until 4 PM CDT this afternoon for
     LSZ142>148-150.

&&

$$

DISCUSSION...Britt
AVIATION...NLy
MARINE...NLy