146
FXUS63 KDLH 152338
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
638 PM CDT Mon Jul 15 2024

.KEY MESSAGES...

- A few strong thunderstorms remain possible in northwest
  Wisconsin and east-central Minnesota through early evening
  today. There is up to a 5 percent chance of severe storms in
  this similar area today.

- Beyond isolated showers and storms in far northern Minnesota
  Tuesday, a dry work week is expected.

- Temperatures at to slightly below normal Tuesday through
  Thursday warm to normal again by the weekend.

&&

.DISCUSSION...
Issued at 236 PM CDT Mon Jul 15 2024

Satellite imagery and mid-level heights analysis shows a low
pressure centered in the North of Superior in Ontario draping a
cold front along the North Shore presently dropping
southeastward into northwest Wisconsin over the next few hours.
As the front pushes into a better strong thunderstorm
environment away from the St. Croix Valley counties in NW WI
over the next two hours, expect the best strong storm potential
from 4-6 PM late afternoon / early evening today. Forecast model
soundings have trended less favorable for severe storm potential
beyond an isolated strong storm potentially pulsing up to
produce hail bordering on the size of a quarter or a wet
microbursts driving winds to 60 mph. These conditions are due
to mesoanalysis of the afternoon environment showing less
favorable conditions for sustaining thunderstorm updrafts. While
the threat of a severe storm cannot still be ruled out, the
potential has trended lower over the last 12 hours.

The strong, very limited severe threat, ends after 7 PM this
evening as the cold front drops south of the Northland into
central Wisconsin. Winds shifting to northwesterly are already
being seen on surface observations in north-central Minnesota
behind the frontal passage. The northerly flow aloft will usher
in a cooler airmass into the region overnight and allow some
overnight temperatures to drop to the low to mid-50s by early
Tuesday morning. As the colder northern Canadian low rotates
through northwest Ontario tomorrow, the cooler temperatures with
sufficient daytime heating will spark some diurnal showers and
thunderstorms in far northern Minnesota Tuesday afternoon. Very
localized rainfall amounts to one-quarter inch and lightning
strikes would be the primary hazards Tuesday afternoon mainly
north of US Hwy 2. As weak mid-level forcing aligns with mid-day
instability in inland northwest Wisconsin late morning tomorrow,
a line of rain showers cannot be ruled out for Washburn through
Price Counties from late morning to late afternoon.

Strong surface to mid-level high pressure Tuesday night and cold
temperatures in the low levels down to 5 C are expected to
promote some overnight low temperatures Tuesday night into the
upper-40s where winds decrease enough overnight.

A cool and dry mid-week will occur Wednesday and Thursday before
that coldest airmass shifts east of the region Thursday night to
build temperatures back towards normal Friday into the weekend.

A return to more southwest to westerly flow should allow
increased moisture by this weekend and coincide with warming
temperatures to create a return to widely scattered rain and
thunderstorm potential (20%) by Saturday afternoon. This pattern
of only slightly above normal around 80F and widely scattered
storm chances last into early next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 638 PM CDT Mon Jul 15 2024

A line of heavy rain with embedded thunder currently impacting KHYR
will move through within the next hour. MVFR fog development will be
possible (30% chance) in HYR late tonight into early Tuesday
morning. Otherwise, expect VFR conditions across the region through
the period following a cold frontal passage. There is a chance for
scattered showers across the Arrowhead and far north-central MN
tomorrow afternoon along with gusty northwest winds.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 158 PM CDT Mon Jul 15 2024

Strong thunderstorms along both the South and North Shores
remain expected through early this evening, creating erratic
wind gusts to 30 knots. Light westerly winds persist Tuesday
ahead of northerly winds gusting to 20 knots Wednesday.

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

&&

.HYDROLOGY...
Issued at 619 AM CDT Mon Jul 15 2024

A Flood Advisory continues across portions of the Rainy River
Basin, extending from Lac La Croix to as far west as the Rainy
Lake outlet. This advisory has now been extended again through
Tuesday afternoon as high water has been slow to move through
the system due to the heavy rains in June and more intermittent
rainfall in the first half of July. The Vermilion River has now
fallen below action stage, and Lake levels on Lac La Croix and
Crane Lake have already passed their crests last week, but are
still elevated and very slow to fall. Lake Namakan and
Kabetogama both reached their crests this weekend, and are also
very slow to fall. Rainy Lake also appears to be cresting as the
flood wave moves through.

Both Rainy Lake and Namakan lake levels are still exceeding the
rule curve, however we should see lowering water levels
throughout the week even despite the spotty 0.5-1 inch of
additional rainfall forecast with storms today (Monday). This
additional rainfall may cause brief rises in tributaries and
extend the period of high water, but is not expected to
significantly change water levels. Boaters should expect high
water, potentially hidden underwater hazards (including
submerged docks), and strong currents in constricted areas. Some
of the storms today 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...NLy
AVIATION...Unruh
MARINE...NLy
HYDROLOGY...Rothstein