FXUS63 KDLH 060233

Area Forecast Discussion
National Weather Service Duluth MN
933 PM CDT Fri Jun 5 2020

.SHORT TERM...(This evening through Sunday night)
Issued at 325 PM CDT Fri Jun 5 2020

A field of cumulus clouds have percolated through northern MN this
afternoon. At the surface gusty winds out of the northwest continue
as a surface high builds out of the Canadian Prairies. Look for
winds to taper off this evening as the pressure gradient weakens
with the eastward propagation of the high. Cloud cover will also
disperse with the loss of day time heating giving way to clear skies
overnight and lows dropping to the mid 40s.

A very active weather pattern begins to take hold of the Northland
this weekend. A meridional pattern is over the region with an upper
level ridge transitioning to the east Saturday evening as a strong
jet is digging south of an upper level low sitting off the west
coast. A surface low over MT will have a warm front draping
southeast into the Central Plains. Saturday will be our transition
day with clouds building in from the west as a surface high over the
region gets shunted off to the east.

Saturday afternoon into Sunday warm air advection begins to start
pumping back into the Northland and a shortwave propagates across
the Dakotas into MN giving way to the first round of showers and
thunderstorms. The latest model runs have a good consensus of
precipitation moving into MN Saturday night and lingering into
Sunday. With the exception of the NAM, models are trending to keep
the stronger storms to the west and south Saturday night. MUCAPES
over the region range from 100-200 J/kg.

The second round of storms is looking to have the better synoptic
drivers to produce strong to severe storms. A warm front will
propagate through the Northland carrying with it a moisture plume
from the Central Plains and a low level jet out of the south at
40kts. This warm moist environment will have SBCAPE values over 1500
J/kg with some models on the higher end of over 3000 J/kg. The
storms are likely to initiate to our west and will have potential to
be severe with large hail and strong winds. With the mean wind flow
out of the southwest these storms could traverse into our western

.LONG TERM...(Monday through Friday)
Issued at 325 PM CDT Fri Jun 5 2020

Monday will see temperatures rise to the lower 90s with the passage
of the warm front from Sunday night. Strong surface heating along
with the low level moisture already in place will give way to
another volatile environment. A surface low traverses northeast and
a strong cold front will crash through MN. Another round of rain and
thunderstorms will accompany this boundary as it moves across the
region. Strong to severe storms will be possible going into the
afternoon hours with deep layer shear still over the northern MN.
SBCAPEs are also trending higher with newer model runs with values
now exceeding 1500 J/kg.

As we head into Tuesday and Wednesday our chances for precipitation
will continue. The remnants of Tropical Storm Cristobal will glide
up the Mississippi Valley and a surge of gulf moisture will
accompany it. PWAT's increase with this feature with values climbing
to over 1.5 inches. The extremely saturated column of air will have
less instability leading to less thunderstorm development and more
of a heavy rainfall event. The main dilemma with this synoptic set
up at this time is the speed of the low pressure left behind from
Cristobal. There is good agreement with the low advancing through WI
and northeastward. However, the GFS is leaning towards advancing the
moisture and low pressure quickly to the northeast while the ECMWF
and the Canadian are taking a much slower progression.

Calmer weather conditions will finally move in Friday as a surface
high pressure builds back in and an upper level ridge sets up for
the weekend.


.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 639 PM CDT Fri Jun 5 2020

VFR conditions will continue through the TAF period, thanks to an
area of high pressure remaining in control over the region. The
diurnally driven cumulus cloud field across our northern TAF
terminals, as well as the gusty northwest winds ongoing across the
region, will gradually diminish this evening, leading to very
light and variable winds for most locations. Winds look to remain
relatively light during the day Saturday, with some higher clouds
filtering in ahead of a warm front that will bring chances of
showers and thunderstorms to the Northland for Saturday night into
Sunday morning.


Issued at 933 PM CDT Fri Jun 5 2020

Calm conditions are expected across western Lake Superior tonight
through Saturday morning, thanks to an area of high pressure that
will remain in control over the region. Winds will generally
range between 5 to 10 knots tonight, with wave heights of 2 feet
or less. As the high pressure ridge axis passes through tonight
into Saturday morning, expect winds to turn from the northwest
this evening to more east to northeasterly during the daylight
hours Saturday. Some stronger winds between 10 to 15 knots will be
possible over the far southwestern arm of the lake Saturday
afternoon into Sunday.

More active conditions are expected for Sunday as a warm front
passes through the region, which could bring some showers. A
tightening surface pressure gradient will help bring some stronger
northeast winds, which could generate conditions hazardous to
smaller vessels.


DLH 48 67 46 66 / 0 10 60 60
INL 44 72 48 70 / 0 20 70 80
BRD 48 75 56 82 / 0 30 60 50
HYR 48 75 52 78 / 0 10 40 50
ASX 49 66 47 74 / 0 0 50 50




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