Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 240543
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1143 PM CST Tue Jan 23 2018

.SHORT TERM...(This evening through Wednesday)
Issued at 326 PM CST Tue Jan 23 2018

The main concern during the short term period involves the
potential for light snow across northern and northeast Minnesota
into northwest Wisconsin on Wednesday.

High pressure in the wake of yesterday`s winter storm has kept
most of Minnesota sunny to partly cloudy today. Northerly flow
over western Lake Superior has supported stratus and snow showers
downwind from the lake over northwest Wisconsin. Meanwhile a
shortwave trough and associated vort max was observed along the
Saskatchewan/Manitoba border near The Pas. A nearly stationary
front extended south from the trough through the Red River Valley.

As the shortwave trough pushes southeastward overnight, the
frontal boundary will advance eastward as a warm front moving
into the Northland Wednesday morning. Isentropic ascent over the
frontal surface has supported an area of stratus over the Red
River Valley this afternoon and is expected to move eastward into
the western CWA late this afternoon and early this evening. Winds
in the boundary layer will back northwesterly and eventually
westerly over northwest Wisconsin tonight pushing the cloud deck
east of northwest Wisconsin for a time. The clearing will be brief
as the stratus from the west will arrive before sunrise. Cold air
will continue pouring onto Lake Superior from the north and east
overnight with long residence times expected. Sensible heat and
moisture flux will deepen the mixed layer over the lake through
the night. Winds off the north shore will back southerly as the
surface ridge axis passes off to the east. The light southerly
return flow may be strong enough to advect the lake modified
parcels inland along the north shore Wednesday morning ahead of
the approaching shortwave. A several hour period of lake effect
snow is possible from Two Harbors to Grand Portage during the
morning hours. By afternoon, falling heights and an approaching
elevated cool front should provide additional lift for widespread
light snow showers over much of northeast Minnesota. Seeder/feeder
processes along the north shore should help boost snowfall
amounts. However, with limited moisture across the board, the
highest snow totals will likely be around 2 inches.

Temperatures will be relatively warm tonight and again on
Wednesday with readings remaining above normal.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 326 PM CST Tue Jan 23 2018

The extended period will remain quiet with mild temperatures
impacting the region into the weekend before cooling down once more.
No strong storm systems are expected in the long term period.

The initial period continues on the light snow showers across the
Arrowhead and portions of the north shore of Lake Superior as drier
conditions take hold due to the arrival of the upper level ridge.
This ridge will extend from Four Corners region northward through
Montana and into Saskatchewan and Alberta Wednesday night before
passing through the Northland Thursday evening. This ridge will be
accompanied with strong warm air advection that will have max
temperatures on Thursday reaching into the upper 20s and low 30s
while Friday temperatures will rise into the mid to upper 30s and
low 40s across northwestern Wisconsin. Models differ on the max
temperature for Friday with the spread going warmer into the upper
30s and lower 40s on Friday but with recent snowfall cover across
northwestern Wisconsin, think the models are going too warm on
temperatures and extending how far the warm air advection extends
northward. Dry conditions will persist Thursday through Friday
morning as an area of low pressure will move in behind the warm air
advection with light wintry mixed precipitation chances across the
International Border region. Winds will turn from the northwest with
the passing of the low Saturday night giving the rise to increased
light snow potential across the south shore of Lake Superior,
particularly Ashland and Iron County. Light lake-effect snow showers
will be possible through the remainder of the weekend into portions
of Monday afternoon. Highs Saturday will dip back into the mid to
upper 20s with low 30s across portions of northwest Wisconsin and
Sunday into the upper teens along the Range and low 20s across
Wisconsin.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1141 PM CST Tue Jan 23 2018

An approaching upper level shortwave and weak frontal boundary
will bring gradually deteriorating conditions to the Northland TAF
sites through the night. There have been some reports of patchy
freezing drizzle just west of KBRD, and we do expect that some
patchy freezing drizzle will move into the KBRD vicinity during
the early morning hours. Some of this may even spread into KINL
and KHIB overnight as well. Otherwise, we expect conditions to
become largely MVFR to IFR, and then remain moreso in the MVFR
range for Wednesday and Wednesday evening. Some visibility
restrictions are possible, but generally in the MVFR range.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH   7  25  14  29 /  10  20  10   0
INL  -1  24  10  29 /  20  20  10   0
BRD   8  28  15  32 /  20   0   0   0
HYR   5  27  10  31 /   0  10  10   0
ASX   7  26  12  31 /  10  20  10   0

&&

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

$$

SHORT TERM...Huyck
LONG TERM...LE/WM
AVIATION...DAP


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