537
FXUS63 KDLH 150839
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
339 AM CDT Mon Jul 15 2024

.KEY MESSAGES...

- A couple rounds of showers and storms today. There`s a ~5%
  chance that a few storms could be strong to severe, possibly
  containing damaging winds and large hail.

- Temperatures cool off a bit mid-week and rain chances
  decrease.

- Temperatures warm back into the low 80s for highs over the
  weekend with a little rain possible.

&&

.DISCUSSION...
Issued at 339 AM CDT Mon Jul 15 2024

We have some mixed weather conditions out there this morning. A
potent trough roughly over the ND/MN border is producing showers
and thunderstorms, the anvils of which are bringing higher
clouds mainly to north-central MN at this time. Further east and
south, where skies are clear to partly cloudy, some fog has
developed. Expect cloud cover to increase this morning as the
upper level trough approaches from the west.

There is a small (and decreasing) threat for a few strong to
severe storms this morning (<5% chance) for southern parts of
Cass/Crow Wing counties along with general chances for showers
and storms across the region (~40-75% chance). The most likely
scenario is that storms will continue to track along a CAPE
gradient that is roughly situated along the I-94 corridor,
keeping most (if not all) of the severe weather threat this
morning south of the Northland. The storms that will affect the
Northland this morning should all be elevated, and as such,
threats for large hail or damaging winds are certainly minimized
(but not zero). Some of the stronger storms could produce wind
gusts to around 50 mph and small hail around the Brainerd Lakes.
Storms will continue to weaken as they move east during the
morning as they run into more stable air, and as such, the main
threats will be the usual thunder/lightning and occasionally
heavy rain.

As the upper level trough slowly pushes through this afternoon,
the CAPE gradient will slowly move east along with it. With
increasing daytime instability, additional storms are likely to
fire across northeast MN first around mid-day to early
afternoon, then move into northwest WI through the afternoon.
The most unstable air associated with warm air advection will
remain to our south, but just enough may inch northward to keep
a ~5% chance for damaging winds (to 60 mph) and large hail (up
to 1" to 1.25") especially in northwest WI. Hodographs are
largely unfavorable for tornadoes, but there might be the
smallest sliver of a chance (~1%) for a brief spinup with some
low-level veering under the warm air advection regime this
afternoon, again mainly over northwest WI. The afternoon threat
for any strong/severe storms is expected to be short-lived, and
storms should exit the region to the southeast by sunset.

We will have PWATs hovering around 1.25" today. This is in the
higher end of climatology, but less than 90th percentile. Most
places can expect to see up to half an inch of rain, but locally
higher amounts up to 1"-2" can`t be ruled out in the more
persistent thunderstorms. This could lead to some brief ponding
of water, but the progressive nature of these storms is expected
to keep any flooding threats very minimal.

After the main trough passes through this afternoon, the showers
and storms could largely clear out with northwesterly flow, weak
cold air advection, and drier air moving in. A few models
suggest the possibility for a few lingering light showers into
tonight, but confidence isn`t high enough to include a mention
in the forecast at this time.

Going into Tuesday, we start a noticeable cool down in
temperatures as more relatively colder air moves in from the
northwest. In addition, another upper level trough may bring
some showers and possibly a few non-severe thunderstorms to
parts of the region, especially along the Canadian border.

Wednesday is looking like the coolest day of the week with high
pressure settling roughly over the ND/MN border. Highs in the
upper 60s and low 70s will allow us to give air conditioners a
bit of a break!

A southwesterly flow pattern will gradually set up later in the
week into next weekend, which should warm temperatures up again.
Rain chances don`t look impressive, but there are some hints for
some sort of weak system over the weekend that could bring a
little rain.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1245 AM CDT Mon Jul 15 2024

Fog will be possible over the next several hours, mainly at HYR
and possibly DLH/HIB. A bit of haze from smoke aloft could also
briefly affect INL/HIB over the next several hours. MVFR
visibilities are possible. Then, an upper level trough and weak
surface cool front will bring showers and thunderstorms from
west to east through the morning. The best thunder chances will
be at BRD (about 60% chance) and about 30-40% chance elsewhere.
MVFR to briefly IFR visibilities will be possible as showers and
storms pass through this morning. Redeveloping storms are
expected to develop around mid- afternoon in northeast
Minnesota, then spreading into Wisconsin during the afternoon.
There is a ~5% chance that some of these storms could be strong
to severe containing strong winds and hail. Aside from storm
chances, west winds will strengthen this morning, becoming
northwesterly around 10 kt and gusting to 20 kt this afternoon
before weakening during the evening again.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 339 AM CDT Mon Jul 15 2024

Wind directions will be a bit variable this morning with speeds
less than 10 kt, then becoming mostly westerly by the afternoon
with gusts to around 15 kt. There will be rain and thunderstorm
chances today (50-80%). Isolated strong to severe storms can`t
be ruled out, which could produce strong winds or hail up to
quarter size (<5% chance). West to northwest winds persist
through Tuesday with gusts not expected to exceed 15 kt for the
most part.

For the open water discussion, refer to the NWS Marquette Area
Forecast Discussion at weather.gov/mqt.

&&

.HYDROLOGY...
Issued at 648 AM CDT Fri Jul 12 2024

A Flood Advisory continues across portions of the Rainy River
Basin, extending as far east as Lac La Croix and as far west as
the Rainy Lake outlet. This advisory has now been extended
through Monday afternoon. Lingering high water from rains in
June continue across the Rainy River Basin. The Vermilion River
continues to fall. Lake levels on Lac La Croix and Crane Lake
have crested, but are still elevated and slow to fall. Lake
Namakan looks like it is now cresting as of Friday morning.

All this high water continues to lead to slowing rises on
downstream lakes, notably Kabetogama (Kab) lake where minor
flooding continues, and on Rainy Lake where levels are still
exceeding the rule curve. Kab and Rainy Lake crests should
occur this weekend. This could bring Nam/Kab just under 1120
feet with a peak level somewhat similar to the high water during
the summer of 2014. This is still 2 feet or more below the high
water levels of Spring 2022 - we are nowhere close to that
level of flooding and extreme rises to that point are currently
not expected. As is usual for this basin, water will move slowly
and recessions will happen at glacial speeds with some flavor
of high water possibly continuing through the month. However,
peak should happen soon, based on latest observations.
Additional rainfall may cause brief rises in tributaries and
extend the period of high water in core lakes depending on where
and how much rain falls with several rounds of showers and
thunderstorms late tonight through Monday. Boaters should expect
high water, potentially hidden underwater hazards (including
submerged docks), and strong currents in constricted areas. Some
of the storms this weekend could be strong to severe, which
could lead to erratic gusts out of thunderstorms and impact wave
heights, as well.

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...None.

&&

$$

DISCUSSION...JDS
AVIATION...JDS
MARINE...JDS
HYDROLOGY...Rothstein