305
FXUS63 KDLH 081123
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
623 AM CDT Mon Jul 8 2024

.KEY MESSAGES...

- Several more days of afternoon/early evening pop up showers and
thunderstorms expected Monday and Tuesday before drier conditions
become more prevalent mid week.

- Steadily warming temperatures through the week and into the
weekend. Above normal low and high temperatures expected leading to
increased heat risk.

- High water persists across the Rainy River Basin and a Flood
  Advisory is in effect, now until Friday. See Hydro discussion
  for more details.

&&

.DISCUSSION...
Issued at 401 AM CDT Mon Jul 8 2024

A calm and quiet early morning has developed across the Northland
with patches of fog becoming steadily more widespread. Expect areas
of widespread thin fog and some patches of dense fog by the time the
sun is coming up, but this should burn off fairly quickly through
the morning hours.

Upper level troughiness persists over the Upper Mississippi Valley
and northern Great Lakes today, which will allow yet another
blossoming of afternoon convection. We remain in a moist environment
with precipitable water values still over 1 inch and with fairly
light upper level winds which may lead to slow storm motions and
give anyone under todays showers and storms a good little downpour.
Rainfall should largely be a couple tenths of an inch or less but a
couple locally higher bullseyes are possible.   The best upper level
support and a little shear (maybe 15-20kts bulk shear) will be over
portions of NW WI, where the best potential for a stronger storm is
with some gusty winds and small hail. No severe storms are expected.
With the loss of daytime heating and the upper level vort max moving
eastward, expect shower/storm coverage to once again dissipate
quickly through the evening hours. Another round of some patchy fog
could be possible overnight into Tuesday morning.

Our upper level trough will be hard to shake and continues into
Tuesday, which will, you guessed it, make for another shot at
afternoon showers and non-severe thunderstorms! Another little vort
max comes spinning down through the afternoon and evening which
could help force an isolated stronger storm once again. With this
northwesterly flow however, some smoke from Canadian wildfires
(originating from northern British Columbia and Alberta) could start
to make its way across the Northland. Higher concentrations are
currently modeled to stay aloft and further north, but some lighter
concentrations could make it to the surface, especially with an
assist from afternoon thunderstorms mixing the lower atmosphere.
MPCA currently forecasts much of NE MN to increase to moderate AQI
(still below the "unhealthy for sensitive groups" category however)
through today into Tuesday, and is being closely monitored for the
potential to higher AQIs. WI DNR has NW WI outlooked in Good AQI,
but those forecasts will be updated later today.

A couple more scattered showers could be possible Wednesday, but
into Thursday we should be looking at some upper level ridging
bringing a fairly precipitation free day. Some more weak
disturbances are possible into the weekend, but no major storms are
expected at this time. WAA will be picking up into the weekend, with
some of the warmest temperatures of the summer so far moving in.
Widespread temperatures in the mid to high 80s are likely and some
temperatures nearing 90F could be possible. Current HeatRisk shows
much of the area in a 2 out of 4 level late this week and into the
weekend - this level of heat affects most individuals sensitive
to heat, especially those without effective cooling and/or
adequate hydration. This is further emphasized by overnight lows
warming as well, largely staying in the 60s overnight. These
above normal temperatures may continue through mid to late
month, per latest CPC graphics.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 623 AM CDT Mon Jul 8 2024

Patchy MVFR to IFR fog across much of the area this morning,
affecting just about every terminal except DLH. Fog is not too far
off, so kept at least MVFR vis in for DLH through the next couple
hours. Visibilities should steadily improve over the next hour or
two becoming VFR quickly. Expecting another round of afternoon
showers and thunderstorms today. Coverage will be scattered but
could bring a quick reduction in vis and ceilings if a storm comes
right over a terminal. Should see coverage in these showers greatly
diminish through this evening with conditions returning to clear and
VFR. Another round of some patchy fog possible overnight into
Tuesday morning.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 401 AM CDT Mon Jul 8 2024

Largely calm conditions expected to persist. Patchy dense fog is
likely this morning, but should burn off quickly through the morning
hours. Some afternoon showers and thunderstorms could lead to brief
gusty winds today and tomorrow. Southwesterly winds 5-10 knots today
through midday Tuesday, then winds become 5-10 knots out of the
north to northeast through Thursday. With temperatures steadily
warming on the mainland into the 80s by mid to late week, these
northeast winds could be slightly enhanced in the afternoon by a
lake breeze circulation but gusts over 15knots are currently not
expected.

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

&&

.HYDROLOGY...
Issued at 401 AM CDT Mon Jul 8 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 been extended through
Friday, but as headwaters level begin to crest, may be trimmed
in its areal extent through the week. Lingering high water from
rains in June continue across the Rainy River Basin. Far
headwaters gauges on the Kawishiwi River, Basswood River, and
Lake Vermilion have crested and are slowly but surely coming
down, but remain elevated (Lake Vermilion still a foot above its
pre-rain level). The Vermilion River continues to fall once
again, falling at a rate of a couple inches each day, and the
River Flood Warning may be able to be canceled in the next day
or two should these recessions continue. This has allowed the
lake level increases on Crane Lake to slow considerably, with
less than an inch of rise in the last 24 hours. Lac La Croix
levels are beginning to show signs of cresting, as rises in the
last day have been less than an inch as well (around 2cm), after
some much faster rates of rise earlier this month. 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 are high but
no flooding is ongoing, per latest reports and webcams. Per the
latest IJC water level bulletin, dam operators are working to
maximize outflow through the basin. However, the sheer volume of
water moving through will still result in additional rises on
these lakes. As water levels upstream crest and begin to come
down, rates of rise on Nam/Kab should begin to slow and
eventually crest, and levels continue. We`ve already seen the
rates of rise begin to demonstrate signs of slowing. From July 1
to 3rd, Nam/Kab Lakes were rising at 2- 2.5" per day, but have
slowed to 1-1.5"/day over the weekend. General guidance suggests
peak levels on Nam/Kab could be possible this week, but that is
uncertain. As is usual for this basin, water will move slowly
and recessions will happen at glacial speeds. 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...Dense Fog Advisory until 10 AM CDT this morning for LSZ121-
     140>148-150.

&&

$$

DISCUSSION...Levens
AVIATION...Levens
MARINE...Levens
HYDROLOGY...Levens