Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 131810
AFDDLH

Area Forecast Discussion
National Weather Service Duluth MN
1210 PM CST Sat Jan 13 2018

.UPDATE...
Issued at 1210 PM CST Sat Jan 13 2018

Updated for the new 18Z Aviation Discussion below.

&&

.SHORT TERM...(Today through Sunday)
Issued at 335 AM CST Sat Jan 13 2018

A sunny but cold Saturday today as an area of high pressure builds
across the Midwest. Increasing clouds tonight as a clipper
approaches, with a round of light snowfall expected Sunday into
Sunday night across the Northland. Around 1-2 inches of snowfall is
expected through the day Sunday. Highs in the single digits near
zero today. Lows tonight around 10 to 20 below zero with wind chills
20 to 35 below zero. And then a bit warmer on Sunday as a warm front
builds in from the west, highs in the single digits above zero.

On the synoptic scale northwest flow has returned to the Upper
Midwest as a strong mid/upper level ridge has developed over the
west coast with a broad longwave ridge across the Great Lakes
region. A mid-level shortwave trough will amplify and approach the
Upper Midwest on Sunday supported by a 140kt 250mb jet streak,
leading to decent amplification by the time the large-scale lift
from the deepening wave reaches the Upper MIdwest. The clipper will
ride along a warm front boundary approaching from the west, leading
to warm air advecting aiding the large-scale lift. In addition,
forecast soundings depict a nearly isothermal layer through the
dendritic growth zone when the best large-scale lift will be moving
across the Northland. All of these factors will combine to form a
decent round of snow Sunday, with the pattern having the potential
for an "overachieving" clipper. Snowfall amounts and timing has been
bumped up just a bit, with daytime snowfall around two inches for
most locations in northeast Minnesota and adjacent areas of
northwest Wisconsin. In addition to the snow, breezy southerly winds
around 15-20 mph may causes snow to blow or drift, leading to
visibility of a half mile or less during the heaviest snowfall.

.LONG TERM...(Sunday night through Friday)
Issued at 335 AM CST Sat Jan 13 2018

A weak system exits the forecast area on Monday though snow showers
will linger over the Gogebic Range through Tuesday.

The next bout of cold air slides over the region with temperatures
dropping to -25 F near I-falls to -10 F near Hayward Tuesday
morning. Then the region starts a warming trend that brings highs
into the mid 20s by Thursday though still no sign of significant
precipitation until the weekend. Models begin to diverge greatly on
Friday as flow turns zonal, so less confidence in precip chances
after this.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1210 PM CST Sat Jan 13 2018

The widespread VFR conditions will continue through at least most
of tonight. Expect clear skies as high pressure moves through the
Upper Midwest today. Light southerly flow will develop tonight and
there will be increasing cloud cover and lowering ceilings from
the northwest overnight into Sunday morning because of an
approaching Canadian Clipper. This area of low pressure will
likely develop MVFR ceilings over north-central and central
Minnesota by the middle to late morning, and into the rest of
northeast Minnesota and northwest Wisconsin by the early to middle
afternoon. Also expect snow to spread into the region from the
north and west, bringing widespread IFR/MVFR visibility.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  -1 -15   8  -6 /   0   0  90  40
INL  -2 -20   6 -15 /   0  50  80  10
BRD   0 -16  11 -12 /   0  10  90  20
HYR   2 -18   8  -1 /   0   0  90  70
ASX   3 -15  11   3 /   0   0  80  70

&&

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

$$

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



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