Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 221720
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1120 AM CST Wed Nov 22 2017

.UPDATE...
Issued at 1120 AM CST Wed Nov 22 2017

Please see the 18Z Aviation Discussion below.

&&

.SHORT TERM...(Today through Thursday)
Issued at 348 AM CST Wed Nov 22 2017

The main focus is on the light snow forecast for later today, but
otherwise Thanksgiving Day will be free of any precipitation to
affect travel related to the holiday.

We will be recovering from yesterday`s cold snap today. An area
of high pressure will move through the Northland early today,
bringing milder air and a period of sunshine. Highs will be back
to the lower to middle 20s, and without the strong wind. A weak
area of low pressure will move into the Dakotas today and spread
clouds and eventually light snow into the Northland from the west.
There is high confidence in this snow, and high confidence the
snowfall amounts will be less than one inch. The snow will mainly
affect the Northland during the middle of the afternoon through
the evening, and while the snowfall will be light, it could make
for icy conditions for travelers on the roads.

Another area of high pressure will move through later today and
early Thursday. Southerly flow will develop Thursday, bringing
warmer air into the region. Expect partly cloudy skies and highs
ranging from the middle 20s near the Canadian border to the lower
30s from central Minnesota into northwest Wisconsin.

.LONG TERM...(Thursday night through Tuesday)
Issued at 348 AM CST Wed Nov 22 2017

A strengthening system passes just to the north of the Canadian
Border on Friday evening. As it approaches, it overruns cold air
causing a freezing rain threat in the Minnesota Arrowhead on
Thursday evening through the system is fairly starved for moisture
at this time, so expect only light ice accumulations. The
sharpest point of the upper level forcing trough passes overhead
Friday afternoon as we`re solidly in the warm sector causing just
cold rain before transitioning over to snow Friday night with only
light accumulations expected as colder air funnels in.

High pressure builds through Monday before the next system begins
to move into the area. A potential frontogenetic band sets up
near the forecast area Monday evening which causes some concern
especially if the more aggressive GFS deepens a low over
Wisconsin sending a deformation band over areas that may have
previously experienced some snowfall in the frontogenetic band.
Either way, there still is a lot of uncertainty in this timeframe
since there still is a lot of disagreement between models. It does
bear watching though as the 00Z GFS solution would be quite
impactful.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1120 AM CST Wed Nov 22 2017

Snow will spread in from northwest to southeast this afternoon
into the evening hours as a shortwave quickly moves through. This
will bring lowering ceilings to MVFR levels, generally between
1200-2500 feet. In addition, snow will reduce visibility to
MVFR/IFR conditions. Confident on the ceilings as the latest
guidance is in good agreement with current observations. Less
confident on visibilities, but utilized upstream observations to
get an idea on how low visibilities will drop at times.

Snow will end at all terminals between 01-06Z. Afterwards VFR
conditions are expected as high pressure builds in.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  24  17  30  27 /  60  80   0  10
INL  21  13  27  26 /  60  30  10  10
BRD  26  19  34  31 /  40  20   0  10
HYR  27  19  34  28 /  50  70   0   0
ASX  29  21  34  28 /  50  60   0  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...Small Craft Advisory from 2 PM this afternoon to 4 AM CST
     Thursday for LSZ140-141.

&&

$$

UPDATE...WL
SHORT TERM...Grochocinski
LONG TERM...Wolfe
AVIATION...WL



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