Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 190804

Area Forecast Discussion
National Weather Service Duluth MN
304 AM CDT Mon Mar 19 2018

.SHORT TERM...(Today through Tuesday)
Issued at 257 AM CDT Mon Mar 19 2018

The main areas of focus through the day Tuesday is some gusty
northeast winds over the Twin Ports and upstream areas of Lake
Superior today, with a shot of accumulating snow late tonight and
Tuesday morning near the Brainerd Lakes region.

Today, a Colorado Low will translate across the Oklahoma/Kansas
border, and into northern Arkansas. Areas over the Dakotas will be
under the inverted trough from this Colorado Low, which will slowly
advance eastward today and tonight. While lift appears to be fairly
weak in the inverted trough per the Thaler QG omega progs, available
moisture will increase, especially within the dendritic snow growth
layer. Surface high pressure will also slowly dive southeastward
over northern Ontario Canada. The geostrophic anti-cyclonic flow
around the surface high will lead to a northeast flow over Lake
Superior, and some gusty winds at the head of Lake Superior. Wind
gusts over Duluth and Superior could reach between 20 to 30 mph
later this morning and through the afternoon, with some of the wind
advancing southwestward over Cloquet and Moose Lake. There is a
small chance of some lake effect snow flurries along the North Shore
near Two Harbors and Silver Bay, but no accumulation is expected.
The area of high pressure will bring some colder air to adjacent
areas of Lake Superior today, with highs ranging from the upper 20s
and lower 30s along Lake Superior, to the middle 30s further inland.

Chances of light snow will increase from west to east as the
inverted trough moves in late this afternoon and through Tuesday
morning. Thaler QG indicates the strongest lift will remain over
southern Minnesota, with some weaker lift over our area. The high
pressure over Ontario should bring some drier air over Lake
Superior, so while there is a small chance of light snow over the
Twin Ports, I`m anticipating accumulating snow to remain over the
western portions of our forecast area. The highest likelihood of
accumulating snow will be over the Brainerd Lakes region and over
north-central Minnesota. Generally, snowfall amounts could range
from a few tenths of an inch up to two inches over far southern Cass
county, with up to one inch near Brainerd. The inverted trough will
shift southeast as the Colorado Low advances eastward, so chances of
snow will diminish through Tuesday afternoon. The high pressure
will linger over James Bay into Tuesday evening.

.LONG TERM...(Tuesday night through Sunday)
Issued at 257 AM CDT Mon Mar 19 2018

Much of the extended period will be dry or only feature low chances
for precipitation. Temperatures will be near normal to several
degrees above normal. A storm system will affect portions of the
Northland Friday/Saturday bringing the best chances for
precipitation of the period.

Surface high pressure is forecast to be centered near James Bay with
a ridge extending into western Lake Superior Tuesday evening. An
upper level shortwave will be moving from the Northern Plains into
Minnesota Tuesday night and precipitation associated with the
shortwave will run into drier air from the high. There could be some
lingering flurries in spots Tuesday night but most areas will be
dry. The shortwave will exit the region Wednesday with ridging
becoming dominant. Dry conditions are then expected Wednesday
through Thursday night. There could be some light snow or flurries
at times around Lake Superior as the low level flow remains east to
northeast through much of the extended period. Delta-T values and
deeper moisture are lacking so any snowfall is expected to be quite
light if any occurs at all.

The models have come into much better agreement with a storm system
Friday into Saturday, especially the GFS and ECMWF, compared to 24
hours ago. A deep trough will be moving onto the West Coast Thursday
with a downstream ridge occurring from the Southern Plains into
Manitoba. A strong shortwave will move from the base of the western
trough and cause lee cyclogenesis Thursday/Thursday night. Surface
low pressure will be centered in the Southern Plains by Friday
evening with a baroclinic zone well north of the low. Another
shortwave will dampen the upper ridge over the Northern Plains and
the combination of the shortwave, FGEN, and the low will create an
area of rain/snow late Friday that may start affecting southern
portions of the Northland. The surface low will track east to
northeast and remain well south of the region, but additional
shortwaves and the baroclinic zone may be enough to cause additional
rain/snow in the Northland into Saturday, but at this time, the
bulk of the significant rain/snow will remain south with this


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1230 AM CDT Mon Mar 19 2018

A backdoor cold front will continue to impact the Northland
throughout the period. The other feature that will impact the
region will be a weak inverted trough, that will move eastward out
of the Dakotas on Monday and Monday evening. Conditions will vary
overnight and into Monday between MVFR and VFR, with local IFR
CIG`s for a time overnight. Conditions will largely improve to VFR
on Monday.


DLH  28  15  28  15 /  10  20  20  10
INL  33  13  32  13 /  10  20  20  10
BRD  36  19  32  15 /  10  70  50  10
HYR  36  15  32  14 /   0  10  20  10
ASX  31  14  29  15 /  10  10  10  10


LS...Small Craft Advisory until 10 PM CDT this evening for LSZ141>147.



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