Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 140020

Area Forecast Discussion
National Weather Service Duluth MN
620 PM CST Mon Nov 13 2017

.SHORT TERM...(This evening through Tuesday)
Issued at 322 PM CST Mon Nov 13 2017

The forecast area was between exiting high pressure near the lower
Great Lakes, and developing low pressure in the lee of the Rockies
in Wyoming. Weak warm air advection was occurring ahead of the low.
Most of the region saw some clearing of the clouds today. However,
low clouds are already developing along the Minnesota/Dakotas border
and advecting north and east toward the Brainerd Lakes. The
southerly low level flow will bring more clouds and some fog into
the region from the South. Meanwhile, an embedded piece of energy
will move through the region late tonight. Will see some patchy
drizzle develop over northwest Wisconsin, and up the north shore.
There is a very small chance of some freezing drizzle over northwest
Wisconsin. Have a mention where forecast soundings indicate some may
form. Fog elsewhere.

The southwesterly flow continues Tuesday ahead of the low pressure
system that has formed over the Canadian prairies. A front will push
into the western portion of the forecast area late in the afternoon.
Some drizzle is possible ahead of the front, with the freezing
drizzle over the eastern edge of the Wisconsin forecast area in the
morning. The fog will erode through the morning with the drizzle
continuing and expanding over the rest of the region in the
afternoon as the front approaches.

.LONG TERM...(Tuesday night through Monday)
Issued at 322 PM CST Mon Nov 13 2017

Near-normal temperatures through the work week then a plunge back
towards below normal temperatures this weekend. A chance for light
snow Tuesday night into Wednesday (mainly in far northern
Minnesota), then a more widespread chance for rain/snow Thursday
night through Friday night.

On the synoptic scale a generally zonal pattern through the work
week with a clipper-like mid-level shortwave trough and associated
surface low tracking southeast from southern Saskatachewan towards
the Upper Great Lakes Wednesday into Wednesday night with the
associated cold front moving through the Northland Tuesday night. As
the cold front moves through Tuesday night into Wednesday light snow
is possible in far northern Minnesota, with generally less than inch
expected in the colder northwesterly flow. Winds will ramp up
Wednesday with northwest winds gusting to over 30 mph. As winds
become more northerly Wednesday night a brief period of lake effect
snow is possible over the south shore as some -10C air moves in at
850mb, but with such a progressive pattern do not anticipate much
snowfall accumulation. A ridge of high pressure builds in Wednesday
night, with a small window for clearing skies before a warm front
lifts into the Upper Midwest Thursday afternoon. This front will
result in increasing clouds, a low chance for light precip along the
international border, and warm air advection aloft. Highs in the 30s
Wednesday and Thursday, which is just below seasonable values.

Late-week into the weekend another blast of arctic air for the Upper
Midwest. A surface low will deepen over the Canadian Prairie and lift
northeast Thursday, with another low developing across the Midwest
Friday tracking northeast towards the lower Great Lakes into
Saturday. Guidance is struggling with the evolution and phasing of
these lows, but most guidance depicts precipitation developing along
and ahead of a cold front Thursday night into Friday across the
Northland followed by arctic air of -15C to -20C at 850mb moving in
by Saturday morning. Strong northwesterly winds are also expected
Saturday with gusts over 35 mph possible and temperatures steady or
falling through the day Saturday. Lows fall into the single digits
by Saturday night. Precipitation along and ahead of the front looks
to be a bit less than earlier anticipated, with the better chance
for heavy rain/snow further east into eastern WI, Michigan, and
eastern Ontario. Light to moderate snow amounts (2-6" for most
spots, maybe over 6" for far northern MN) are possible Thursday
night, with precipitation changing over to rain or a wintry mix
during the day Friday, diminishing snow amounts.


.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 615 PM CST Mon Nov 13 2017

Conditions will deteriorate across the Northland as the night
wears on, as abundant moisture lifting northward into the region
will help to generate low clouds, areas of fog, and drizzle and
freezing drizzle. We could see some ice accumulation at some of
the TAF sites, especially during the latter half of the night and
early on Tuesday. Will continue to mention some freezing drizzle
across the region, and watch for any areas that may start to see
any substantial glazing potential. We should see conditions settle
into the IFR or even LIFR range overnight, and then improve only
slightly into the IFR/MVFR range on Tuesday.


DLH  30  40  31  34 /  20  30  50  10
INL  29  40  29  30 /  10  20  30  40
BRD  34  45  30  32 /  10  20  20  10
HYR  31  41  32  35 /  20  40  60  20
ASX  32  43  35  37 /  10  30  50  20




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