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000
FXUS63 KDLH 120521
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1221 AM CDT Fri Apr 12 2024

.KEY MESSAGES...

- Lingering scattered shower and isolated storm chances into
  early evening. Pea size hail, localized wind gusts to 30-40
  mph, and occasional lightning are possible with the storms.

- Slightly cooler on Friday with breezy NW winds, but still
  above average. Widespread 60s this weekend with some low 70s
  possible in southern parts the Northland Saturday through
  Monday.

- A clipper system on Saturday night brings a chance (20-40%)
  for light rain. A few isolated thunderstorms cannot be ruled
  out.

- A large, warm, and wet system is forecast to move through the
  Upper Midwest Monday-Thursday of next week, with the potential
  for thunderstorms and heavy rain increasing. Snow may also
  mix on the backside of this system.

&&

.DISCUSSION...
Issued at 422 PM CDT Thu Apr 11 2024

Rest of Today - Tonight:

Scattered to more widespread showers and a few isolated storms
have developed across much of the Northland this afternoon in an
area of 200-500 J/kg of CAPE/instability and steep low-level
lapse rates. Shear in through the depth of convection is very
weak, with effective shear of 20 knots or less, so any storms
that develop are more of the general airmass variety and
vertically oriented. Thunderstorm chances through early this
evening remain highest from St. Louis south to Pine County in MN
and areas east, including NW WI. Main hazards with any storms
include pea size hail, localized wind gusts up to 30-40 mph, and
occasional lightning. Expect showers/storms to diminish this
evening, but isolated showers/sprinkles should linger into
tonight through Friday morning in the tip of the Arrowhead and
NW WI.

Friday:

A deep low pressure system continues to track northeastward
across southern Ontario and through western Quebec throughout
the day on Friday. This will keep breezier northwest winds
continuing across the Northland throughout most of Friday before
winds weaken Friday evening/night. Gusts up to 20-25 mph are
expected, with some localized gusts up to 30 mph along the North
Shore. Cloud cover will be diminishing from west to east
throughout the day. High temperatures will be in the 50s for
most, and upper-40s for most of the Arrowhead and parts of
north-central WI where cloud cover lingers longest.

This Weekend:

A quick-moving clipper system brings low chances (20-30%) for
light rain mainly north of Highway 2 Saturday afternoon and in
the Arrowhead and NW WI Saturday evening/night. Generally expect
less than a tenth of an inch of rain, with many locations
remaining dry. Also can`t rule out a few elevated thunderstorms
given some weak instability aloft, with the best potential for
any storms from central MN into NW WI.

Otherwise, expect a rebound in temperatures again for this
weekend with most locations seeing highs in the 60s and some
southern portions of the Northland possibly seeing low 70s. Parts
of the Arrowhead and locations near Lake Superior will remain
in the 50s.

Active Spring System Next Monday - Thursday:

Global ensembles and clusters are coming into better agreement
for a potent low pressure system developing in the lee of the
Rockies on Monday that will push through the Plains on Tuesday
and move into the MN/WI vicinity Tuesday night/Wednesday. Still
some spread with regards to the exact low track, but the
Northland looks poised to have a strong frontogenetic zone set
up somewhere across the area with strong synoptic forcing and
upper-level jet support due to a negatively tilted trough aloft.
These features will drive strong moisture return from the Gulf
of Mexico, with anomalous PWATs above an inch at times looking
likely. Ensembles show increasing potential for heavy rainfall
with thunderstorms/convection, particularly Monday evening
through Tuesday night. This heavy rainfall potential is farther
supported by a Day 5 WPC Marginal Excessive Rainfall Outlook for
most of the Northland. NBM 72-hour rainfall probabilities from 7
AM Monday - 7 AM Thursday show 50-65% for >1" of rain from the
Brainerd Lakes into the North Shore and areas south and east,
with probabilities continuing to increase over the past few
model runs. Additionally, plenty of shear will be present across
the area with this system, so there may be some severe weather
potential that nudges into southern portions of the Northland on
Monday Night into Tuesday depending on how far north the warm
sector of this system can push. Right now, the better severe
potential remains just south of the area across Iowa, southern
Minnesota, and southern Wisconsin.

Several ensemble members also show a snow potential mixing in
on the backside of this system late Wednesday into Thursday as
colder air works into the region, but there is still a larger
spread in model solutions in this timeframe. At the very least,
this wetter period next week should help improve drought
conditions across the area.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1218 AM CDT Fri Apr 12 2024

VFR with HREF showing probability for IFR increasing across the
MN Arrowhead. Models have been showing this for awhile now, but
it keeps getting pushed further out it in the future. Wasn`t
confident enough in IFR, so kept the ceilings that do come in in
the morning MVFR, but they`ll only last though midday. Winds
gusty at times from the northwest with decreasing speeds through
time.

&&

.MARINE...
Issued at 315 PM CDT Thu Apr 11 2024

Northwesterly winds begin to pick up later this evening and
tonight, gusting to 20 to 25 knots first along the North Shore,
with building waves to 2 ft to just under 4 ft and gusts over
20 knots along the South Shore starting tonight. Gusts around 20
to 25 knots also develop during the daytime on Friday in the
head of the Lake. Hazardous conditions to small craft continue
through much of Friday before winds and waves diminish Friday
evening. Small Craft Advisories go into effect late this
evening/tonight and continue into Friday afternoon/early
evening.

Winds shift northeasterly on Saturday with gusts up to around 20
knots and waves of 2 to 4 feet possible at the head of the Lake
late Saturday afternoon into early evening. Additional Small
Craft Advisories may be needed.

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
MARINE...Small Craft Advisory until 5 PM CDT this afternoon for LSZ121-
     147-148-150.
     Small Craft Advisory until 9 PM CDT this evening for
     LSZ140>143.
     Small Craft Advisory from 7 AM this morning to 5 PM CDT this
     afternoon for LSZ144>146.

&&

$$

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