711
FXUS63 KDLH 112033
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
333 PM CDT Thu Jul 11 2024

.KEY MESSAGES...

- Hot weather continues to finish out the week.

- Chances for showers and storms return on Saturday, with severe
  weather and excessive rain possible through the weekend.

- Temperatures cool down back below average for mid next week.

&&

.DISCUSSION...
Issued at 201 PM CDT Thu Jul 11 2024

Hazy/milky skies as wildfire smoke aloft is transported south
from fires throughout west/central Canada continue for today
and tomorrow. Temperatures above normal also continue as we
remain under an upper level ridge with widespread highs in the
80s across the Northland. These will continue through the
weekend as the ridge persists.

Global and hi-res models hint at a MCS forming along a surface
trough before trekking across the Northern Plains into the
Northland with a shortwave aloft Friday night into Saturday
morning. However, this is highly conditional of whether lift is
able to overcome strong thermal capping in place with this
ridge and if the MCS is able to form over North Dakota. If it
were to initiate, it would likely remain elevated, with gusty
winds possible. These storms are not expected to be severe.

The better chance for severe weather will be Saturday afternoon
under hot temperatures, dewpoints in the upper 60s/lower 70s,
0-6km bulk wind shear above 30 kts in the western half of the
CWA, and MLCAPE 1000-3000 J/kg. The thermal capping that has
helped to limit the thunderstorm formation will weaken slightly,
which will allow a higher likelihood for convection to
initiate. Main threats will be wind and hail, but tornadoes are
also possible, especially for our western counties. PWATS won`t
be significantly high, but some storms could produce enough rain
to cause nuisance to minor flooding in some areas. Sunday will
host similar conditions as Saturday, but with the highest
chances shifting along our southern counties and the heavy
rainfall threat will either be similar or limited from lowered
PWATs depending on what model you look at.

For those looking for relief from the heat, early next week an
upper level closed low will switch flow aloft to the northwest
which will bring more chances for precipitation and cooler
temperatures for the mid week next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1219 PM CDT Thu Jul 11 2024

VFR conditions for the TAF period. Diurnal cumulus this
afternoon will have bases around 4000ft and will dissipate this
evening. There is the slightest chance (10%) for an isolated
thunderstorm this afternoon. Fog chances increase tonight,
though where it will form is still uncertain.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 201 PM CDT Thu Jul 11 2024

Relatively light and variable winds are expected over Lake
Superior over the next couple days. Wind speeds and gusts should
remain below 15 kts. Slight chances for showers and
thunderstorms over western portions of the lake return
Saturday afternoon. Some storms may be strong to severe on
Saturday.

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

&&

.HYDROLOGY...
Issued at 330 AM CDT Wed Jul 10 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 remains in effect through
Friday, but as levels in waterways further east crest, it may be
trimmed in its areal extent prior to expiring. However, for
areas further west, the Advisory may need to be extended in
time. Lingering high water from rains in June continue across
the Rainy River Basin. The Vermilion River continues to fall.
This has allowed the lake level increases on Crane Lake to slow
considerably, with lake levels having flattened out in the last
12 hours, likely having reached its crest. Lac La Croix levels
are cresting and should begin to slowly recede through this
week.

All this high water continues to lead to steady rises on
downstream lakes, notably Namakan/Kabetogama (Nam/Kab) lakes
where minor flooding continues, and on Rainy Lake where levels
have just exceed the rule curve. Past events have shown there is
a lag between the crest at Lac La Croix and the crest on
Namakan lake of anywhere from 3 to 10 days (the longer coming
from events when rain fell around peak waters). As water levels
upstream crest and begin to come down, rates of rise on Nam/Kab
should begin to slow and eventually crest, possibly by late this
week or this weekend. Rates of rise have slowed to 1-1.5"/day
over the weekend and in the last 24 hours there was only about a
0.5" rise on Kabetogama/Namakan as inflows are decreasing.
Until peak, another 2.5-7 inches of rise could be possible
(estimate, not an official forecast), with the high end of that
range probably being a worst case scenario. This could bring
Nam/Kab just over 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 sooner
rather than later, based on latest observations. Additional
rainfall may cause brief rises in tributaries and extend the
period of high water in core lakes. Boaters should expect high
water, potentially hidden underwater hazards (including
submerged docks), and strong currents in constricted areas.
Generally light winds are expected, except for possible brief
erratic gusts out of thunderstorms, so wave heights should
remain fairly minimal.

&&

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

&&

$$

DISCUSSION...KML
AVIATION...KML
MARINE...KML
HYDROLOGY...Rothstein