144
FXUS63 KDLH 072111
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
411 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 /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1231 PM CDT Tue May 7 2024

A smattering of just about every flight category out there.
While a wave lifts north, the same wave is expected to return
tonight leaving a band of IFR or lower conditions over the
forecast area. Thunderstorms are possible (60 percent chance)
with afternoon convection, but will only extend as far north as
30 nm north of Duluth with the highest chances between 21Z and
03Z. Winds will be gusty to start with but will decrease tonight
leading to potential fog formation.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 410 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...Gale Warning until 6 PM CDT this evening for LSZ140>142.
     Small Craft Advisory until 4 AM CDT Wednesday for LSZ143>146.

&&

$$

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