663
FXUS63 KDLH 302343
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
643 PM CDT Mon Jun 30 2025

.KEY MESSAGES...

- Widely scattered thunderstorms are expected today and again on
  Wednesday across all of the Northland. A few storms may be
  strong. Severe storms are not expected.

- Very warm and muggy conditions are expected Friday.

- Friday PM and Saturday, the next chances for more widespread
  strong thunderstorms set up. A few of these strong storms may
  be severe.

&&

.DISCUSSION...
Issued at 340 PM CDT Mon Jun 30 2025

A compact upper-level trough axis located from far northwest
Ontario to northeast Nebraska this afternoon will propagate
eastward tonight. Ample sunshine has generated 500 to 1200 J/kg
of MLCAPE over northeast Minnesota and northwest Wisconsin with
negligible capping. Showers and thunderstorms will continue to
percolate and move generally eastward across the region through
early evening, gradually diminishing as the modest instability
is used. Effective shear of 20 to 30 knots combined with the
modest CAPE will yield upright storms with limited potential to
generate hail and gusty winds. The strongest storms will be
capable of 30 to 40 mph wind gusts and brief heavy rainfall.
Areas of fog may develop tonight as skies clear and winds become
light.

As upper-level ridging builds over the northern Plains and
Upper Midwest Tuesday, look for mostly sunny skies early.
Diurnal cumulus and a few showers and storms are possible once
again, though the chance is low. The most likely areas for
storms will be along the lake breeze in both the Minnesota
Arrowhead and northwest Wisconsin. Convergence appears greatest
along the North Shore. Even so, PoPs are no higher than 20
percent. Temperatures will trend a little warmer with highs
forecast to reach the middle 70s to middle 80s. A few upper 80s
aren`t out of the question.

Previous discussion for Wednesday through early next week...

Along and south of the Iron Range starting Wednesday morning,
the second more widespread chances of general thunderstorms
build back of the region. The most moist airmass is likely along
and south of US Hwy 2, which coincides with available modest
amounts of CAPE from Wednesday late morning to afternoon. This
will again be a shear-limiting day with up to 35 knots of bulk
shear progged for the Brainerd Lakes to all of northwest
Wisconsin. So expect the best chances of general thunderstorms,
a few strong in far eastern Minnesota and across northwest
Wisconsin, Wednesday mid-day to late afternoon and little to no
activity in the Borderlands.

After a quiet Thursday, convection is likely to initiate in the
Dakotas on the tip of a low-level southerly jet. As a warm
front lifts through Minnesota and western Wisconsin Thursday
night, the Dakota`s convection will be a large factor in just
how unstable of an atmosphere can be available for possible
convection in the Northland Friday afternoon to early overnight.
If storms are able to initiate Friday PM, the other limiting
factor on how organized anything would be is the lower-end shear
profiles depicted by multiple medium-range global deterministic
models. Even with the abundance of CAPE and very moist
atmosphere (precipitable water progged from 1.5 to 2 inches),
current thinking would lean towards more disorganized clusters
of strong to locally severe storms Friday. With the timing of
this late week warm front, a very warm and humid Independence
Day is likely for all areas. Forecast air temperatures right now
range in the mid to upper-80s, but with the dewpoints in the
upper-60s, heat index values approach the mid-90s. This day will
have to be continually assessed for possible heat-related
headline needs, especially along and south of US Hwy 2 in
Minnesota and across northwest Wisconsin.

After the July 4th storm and heat hazard potential, lingering
storm chances Saturday will have to be monitored for strength,
especially east-central Minnesota and northwest Wisconsin as the
cold front aloft still moves through northeast Minnesota.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 627 PM CDT Mon Jun 30 2025

VFR conditions are expected for the rest of the evening, with a
few light showers possible over the next couple hours away from
terminals. Fog is possible at HIB and HYR due to rain showers
throughout the day and clearing conditions overnight combined
with the surrounding wetlands. Winds increase out of the
northwest Tuesday.


&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 340 PM CDT Mon Jun 30 2025

Scattered showers and thunderstorms capable of producing gusty
winds to 30 knots will persist into the evening. Locally higher
waves are expected near storms. There will be additional chances
of thunderstorms Wednesday through Saturday. Storms Friday and
Saturday may be strong to severe. Aside from the thunderstorm
chances, hazardous conditions are not expected this week.

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...Huyck/NLy
AVIATION...KML
MARINE...Huyck