869
FXUS63 KDLH 232128
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
428 PM CDT Thu May 23 2024

.KEY MESSAGES...

- Rain showers and thunderstorms move back into central/north-
  central MN this evening. A few strong thunderstorms are
  possible in the western Brainerd Lakes (small hail and brief,
  gusty winds).

- Moderate rain continues spreading across central/north-
  central MN tonight and the remainder of the Northland on
  Friday. Can`t rule out some strong thunderstorms (small hail
  and gusty winds) Friday afternoon in NW WI.

- Active weather pattern continues with periodic showers and
  storms this weekend into next week, though it doesn`t look
  like anything significant.

&&

.DISCUSSION...
Issued at 429 PM CDT Thu May 23 2024

Rest of Today - Tonight:

A pleasant day has developed for most of the Northland with
mainly sunny skies and light winds. High temperatures top out in
the 60s for north-central and NE MN north of a west-east
oriented stationary front, and low to mid 70s for the Brainerd
Lakes into NW WI. Some cumulus fields have developed around
this frontal boundary, but drier air in the low-levels and
little to no forcing aloft should prevent shower and
thunderstorm development along the front in our area for the
remainder of the afternoon/evening.

With that said, better forcing aloft associated with a shortwave
trough and surface low over the Dakotas has led to thunderstorms
developing in the eastern Dakotas. High-res model guidance shows
these showers and storms gradually tracking eastward into
central and north-central MN very late this afternoon and
evening. There is a brief window (6-9 PM) of the potential for
a couple strong thunderstorms (small hail and gusty winds) with
MUCAPE up to 500 J/kg, effective bulk shear around 35 knots, and
steeper mid- and low-level lapse rates. However the later timing
of these storms means that they will be on a weakening trend as
they approach Cass and Crow Wing Counties, so the better
strong to severe storm chances remain to our west.

This batch of convection continues to spread over central and
north-central MN later this evening into tonight, mainly in the
form of moderate showers and a few embedded thunderstorms. These
aforementioned areas could pick up a quick 0.25-0.5 inches of
rain overnight.

Friday:

The aforementioned low will be over the ND/MN border by 12Z
Friday and track almost due north into Manitoba Friday evening
and night. Moisture advection ahead of the low will surge higher
PWATs (1-1.25", 80-90th percentile of climatology), but most of
the morning precipitation will be in a narrower forced band of
showers/storms quickly moving east Friday morning with
redevelopment of thunderstorms along/ahead of the cold front
across much of the Northland again Friday afternoon into evening
before precipitation departs Friday night. There won`t be much
instability with the morning round of convection, but a potent
50-60 kt low-level jet in the area means that some of the
morning convection could mix down some of the higher winds aloft
to the surface (50+ mph at times). Redeveloping convection
during the afternoon/evening will also have about 300-600 J/kg
of MLCAPE as well as 40 kt of 0-6km bulk shear that should be
sufficient to develop some localized organized updrafts,
particularly in NW WI where the instability will be highest and
low-level lapse rates will be steepest. Strong wind gusts would
be the primarily concern with this second round of convection,
but small hail will also be possible with the strongest storms.
Non-thunderstorm winds will also be breezy out of the east to
southeast on Friday ahead of the cold front, with gusts up to 30
mph.

Total precipitation amounts from this evening through Friday
evening will be 0.5-1 inches over north-central MN, as well as
pockets along the North Shore and in NW WI where stronger
thunderstorms move overhead. Most of the remainder of the area
is poised to see 0.25-0.5 inches of accumulations from the
moderate rainfall.

Saturday:

Surface high pressure passing through the mid-Mississippi River
Valley on Saturday should keep southern portions of the
Northland dry, but parts of NE MN have a 20-30% chance for light
showers and a couple embedded general thunderstorms Saturday
afternoon into Saturday night. Additional rainfall amounts of
0.1 inches or less expected.

Sunday - Early Next Week:

A deeper trough and related developing surface low over the
front range of the Rockies on Saturday will push east across
Missouri/Iowa Sunday morning and then eject northeast into
eastern Wisconsin by late Sunday as the system quickly deepens.
Although there is some slight spread in the model low tracks
with this system, confidence is high the low will track
southeast of our area. However, precipitation bands associated
with the northwestern quadrant of the low should lead to 30-50%
chances for mainly showers with a few weak storms on Sunday into
Monday for the Northland. Highest of these chances will be in NW
WI closer to the low.

Friday`s low that will be long churning over Manitoba for
several days, finally drops back southeast into the Northland on
Tuesday, rounding out light shower chances on Tuesday (30-40%
chances).

Mid - Late Next Week:

Ensembles show general agreement on upper-level shortwave
ridging moving over the Upper Midwest on Wednesday, possibly
lingering into Thursday. This would lead to rain-free conditions
during the middle of next week, though the active pattern is
poised to return late next week with another round of troughing
and associated rainfall moving back into the central U.S.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1254 PM CDT Thu May 23 2024

A few sporadic showers are moving through north-central
Minnesota at the moment, and will affect the vicinity of KINL
and perhaps HIB to a lesser extent for the first half of the
afternoon. Then, showers and storms developing over the eastern
Dakotas mid-afternoon will spread into portions of central
Minnesota very late this afternoon and evening. Have included
VCTS mention at KBRD as it looks as though storms should be
weakening in coverage/intensity as they move into the Brainerd
Lakes region. Showers and a few embedded storms spread across
much of north-central and northeast Minnesota later this evening
into tonight, with showers then moving east across the area
Friday morning and afternoon along and ahead of a cold front
associated with the approaching low pressure system.

Winds begin to quickly ramp up out of the east tonight with
gusts increasing to 20-30 knots on Friday morning, then shift
more southeasterly late Friday morning ahead of the approaching
cold front. Expect some LLWS spreading in from west to east late
tonight into Friday, as well.

&&

.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/...
Issued at 429 PM CDT Thu May 23 2024

Winds will increase again out of the northeast late this evening
into Friday, with the winds being strongest late Friday morning
through afternoon when gusts up to around 35 knots are likely
(50-60% chance) along the North Shore and up to around or
slightly more than 30 knots elsewhere. Therefore, have issued a
Gale Warning for Silver Bay to Grand Portage from late Friday
morning through the afternoon. Small Craft Advisories are in
effect for the remaining nearshore waters of western Lake
Superior from tonight through Friday night with winds then
subsequently weakening to near or just below the lower Small
Craft Advisory thresholds on Saturday and turning southwesterly.
Wave heights peak around 7 to 11 feet on daytime Friday and
finally subside below 4 feet daytime Saturday as winds and waves
diminish.

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...Small Craft Advisory from 3 AM Friday to 4 AM CDT Saturday for
     LSZ121-143>145-148.
     Small Craft Advisory from 3 AM to 10 AM CDT Friday for
     LSZ140>142.
     Gale Warning from 10 AM to 7 PM CDT Friday for LSZ140>142.
     Small Craft Advisory from 3 AM Friday to 1 PM CDT Saturday for
     LSZ146-147-150.

&&

$$

DISCUSSION...Rothstein
AVIATION...Rothstein
MARINE...Rothstein