Beach Hazards Statement 6, NWS Duluth, MN

Area Forecast Discussion
National Weather Service Duluth MN
1238 AM CDT Tue Jul 21 2020

.SHORT TERM...(This evening through Tuesday night)
Issued at 344 PM CDT Mon Jul 20 2020

High pressure will continue to dominate the weather pattern this
evening, leading to dry weather and calm winds. A diurnal cumulus
field currently across the Northland will gradually dissipate
following sunset. Cloud cover will increase, as an upper level
shortwave and associated low tracks eastward into the Northland.
This will lead to widespread showers for much of the day Tuesday.
There is also a chance for a few thunderstorms embedded within the
stratiform region of precipitation.

The possibility of severe weather tomorrow is primarily dependent on
the amount of clearing that might occur. The moisture and wind
environment is favorable, with over 1.25 inches of PWAT and 0-6 km
bulk shear of around 40 knots. However, instability appears to be
the limiting factor. Model MLCAPE values have been in the 800-1200
J/kg range. MUCAPE values are getting closer to 2000 J/kg, but this
is assuming that the stratus associated with the low is able to
clear out in the afternoon to coincide with peak daytime heating.
Currently, the confidence in severe thunderstorm development
tomorrow afternoon is low. However, if skies can clear, all severe
impacts are possible with damaging winds, large hail, and a tornado
or two possible. The shortwave and associated low pressure moves out
of the region Tuesday night, with a dry start to Wednesday expected.

.LONG TERM...(Wednesday through Monday)
Issued at 344 PM CDT Mon Jul 20 2020

Wednesday should start to clear up as the trough moves out of the
area and a ridge dominates over the Northland. Temperatures will
increase into the weekend and reach a peak on Saturday and Sunday
from the advection of warm moist air from the Gulf, with highs into
the upper 80s and lower 90s.

Friday into Saturday, a shortwave should develop over western South
Dakota and progress northeast into our area. Several smaller
shortwaves following the first could keep initiating convection well
into Sunday before moving off to the east.

Monday, conditions become a lot more uncertain between the global
models. Some have Monday staying completely dry, and others have
another round of showers and storms from a shortwave that developed
over the Dakotas.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1238 AM CDT Tue Jul 21 2020

Tonight, upper level clouds can be seen filtering in out ahead of
an approaching system. Radar reveals that rain showers have
entered western MN and continue a steady march east towards
central MN. A few locally heavy downpours are not out of the
question. To accompany these showers most terminals will see
degraded flight conditions due to low ceilings. Look for ceilings
to drop as low as IFR beginning over BRD where upstream obs are
already trending down. Clouds will spread east impacting HIB/DLH
in the early morning. Tomorrow afternoon could see better
potential for some thunderstorms developing and moving east. At
this time the main terminals that have the best chance at seeing
these impacts would be DLH/HYR.

&&

.MARINE...
Issued at 936 PM CDT Mon Jul 20 2020

Widespread rain showers with embedded thunderstorms are expected to
move into Lake Superior from the west in the morning. Some of these
storms could produce strong winds up to 30 kts. General winds
tomorrow should be stronger at 10-15 kts across most of the Lake.
But at the head of the Lake, winds could get up to 20 kts and gusts
up to 25 kts. A small craft advisory may be needed as conditions are
looking borderline at this time. Winds will slightly taper off
Wednesday after the passage of the system.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  56  64  54  71 /  50  90  50  10
INL  54  66  51  76 /  40  70  30  10
BRD  60  72  55  74 /  80  80  20   0
HYR  56  72  55  73 /  40  80  50  10
ASX  50  72  56  72 /  30  80  60  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&

SHORT TERM...Unruh/GSF
LONG TERM...Kossen/GSF
AVIATION...Huyck
MARINE...Britt

Hazardous Weather Outlook
National Weather Service Duluth MN
405 PM CDT Mon Jul 20 2020

MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-211130-
Koochiching-North St. Louis-Northern Cook/Northern Lake-
North Itasca-Central St. Louis-Southern Lake/North Shore-
Southern Cook/North Shore-North Cass-South Itasca-South Cass-
Crow Wing-Northern Aitkin-South Aitkin-Carlton/South St. Louis-
Pine-Douglas-Bayfield-Ashland-Iron-Burnett-Washburn-Sawyer-Price-
405 PM CDT Mon Jul 20 2020

This Hazardous Weather Outlook is for portions of northeast
Minnesota and northwest Wisconsin.

.DAY ONE...This afternoon and Tonight

Thunderstorms will spread across the Northland tonight. No severe
storms are expected.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Some isolated severe thunderstorms are possible south of
Minnesota Highway 210 and Highway 2 in northwest Wisconsin Tuesday
afternoon. Large hail, damaging winds, occasional lightning and
heavy rain are expected. Some localized flooding may occur with
the heavier rains.

A few thunderstorms will be possible in north central Wisconsin
and northeast Minnesota on Wednesday with a better chance Friday
into the weekend region wide. The late week storms could be
strong to severe.

.SPOTTER INFORMATION STATEMENT...

Skywarn spotters may be needed Tuesday afternoon.

LSZ121-140>148-211130-
Bayfield to Oak Point WI-Grand Portage to Grand Marais MN-
Grand Marais to Taconite Harbor MN-
Taconite Harbor to Silver Bay Harbor MN-
Silver Bay Harbor to Two Harbors MN-Two Harbors to Duluth MN-
Duluth MN to Port Wing WI-Port Wing to Sand Island WI-
Sand Island to Bayfield WI-Oak Point to Saxon Harbor WI-
405 PM CDT Mon Jul 20 2020

This Hazardous Weather Outlook is for portions of the Nearshore
waters of western Lake Superior.

.DAY ONE...This afternoon and Tonight

Thunderstorms are possible late tonight. Occasional lightning and
heavy rain will accompany the storms.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Thunderstorms will be possible Tuesday into Tuesday evening.
Although widespread severe storms are not expected, a few could be
severe over the far southwest arm of Lake Superior. The main
threats will be hail to one inch and damaging winds to 60 MPH. The
storms may also produce heavy rainfall.

Thunderstorms will again be possible Friday into the weekend,
storms during this time could be strong to severe.

WFO DLH

More information may be obtained at the following web address:
http://www.weather.gov/duluth (all lower case)