594
FXUS63 KDLH 072326
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
626 PM CDT Tue May 7 2024

.KEY MESSAGES...

- Thunderstorms will occur this afternoon with isolated strong
  thunderstorms mainly south of US Highway 2. The stronger
  storms could produce nickel-sized hail and wind gusts to 50
  mph.

- Fog is expected to form tonight.

- Frost is possible (60% chance) in the Arrowhead Wednesday
  night. A freeze is likely in NW WI Thursday night.

- Two weak clippers cross over the area bringing light rain
  Friday and Sunday.

&&

.DISCUSSION...
Issued at 410 PM CDT Tue May 7 2024

A fairly large and dynamic low pressure to our west is rotating
bands of rain and thunderstorms north into our forecast area
this afternoon. Clearing behind a warm front this morning and
the subsequent heat loss from precipitation and lack of
insolation due to cloud cover has set up a baroclinic zone with
a secondary warm front lifting north this afternoon. A sliver of
MUCAPE sneaks northward into the southern portion of our
forecast area peaking out around 1500 J/kg per the latest RAP
analysis in concert with 20 kts of 0-6 km shear. This gives a
bit of a stronger thunderstorm threat albeit isolated to our
southern border which is pretty close to where the SPC marginal
risk is for this afternoon though I may have extended that line
a bit more west into Aitkin County. Most storms should be run
of the mill, but there may be some overachievers. Luckily the
window for good convection isn`t too large and the stronger
storm threat decreases greatly after 00Z.

The rain that does or has fallen will saturate the BL overnight
causing fog to form though it may be just a low stratus deck as
the waves of precipitation that rotated north over us today sag
back south again overnight bringing low clouds and possibly
drizzle in concert with the fog.

High pressure builds Wednesday with skies clearing overnight
causing temperatures to plunge and this will give the potential
for frost in the MN Arrowhead on Wednesday night. An even
deeper plunge into sub-freezing temperatures across NW WI
occurs Thursday night and will likely need some frost/freeze
headlines.

Afterwards, it`s active, but not too bad with clipper systems
expected Friday and Sunday. Each of these are warm enough for
just plain rain, but also not a lot of rain <0.5" per system and
probably less than 0.25" for most places.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 625 PM CDT Tue May 7 2024

A line of showers and storms is entering from the south this
evening. Severe weather is looking less likely as the evening rolls
on but we have had a few reports of pea sized hail and some gusts
from storms of around 40 kts. This activity will taper off over the
next few hours with showers dissipating around midnight. Overnight,
some fog may develop with the better chances near Lake Superior.
Tomorrow, drizzle and sprinkles will move north to south with
easterly winds through the day.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 625 PM CDT Tue May 7 2024

Still expecting some occasional gales along the North Shore this
afternoon so keeping the gale up there, but did trim off the
southern portion of it. Small crafts follow with a little break
early Wednesday before winds and waves build again. We may flirt
with gales near the Twin Ports again Wednesday afternoon in
strong northeasterly flow.

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 midnight CDT tonight for LSZ140>146.

&&

$$

DISCUSSION...Wolfe
AVIATION...Britt
MARINE...Wolfe