Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 101155 AAA
AFDDLH

Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
555 AM CST Wed Jan 10 2018

.UPDATE...
Issued at 555 AM CST Wed Jan 10 2018

Update for new 12Z Aviation Discussion below.

&&

.SHORT TERM...(Today through Thursday)
Issued at 429 AM CST Wed Jan 10 2018

The Northland can still expect a significant round of snow
tonight and Thursday, as well as light freezing rain prior to the
snow. The latest models have delayed the precipitation a bit, and
there is pretty good agreement in widespread snowfall of 3 to 6
inches. While the NAM suggest there could be a band up to 8 inches
somewhere over or near northwest WI, there have been fluctuations
in the location of that band from the 00Z to 06Z runs. Decided
Winter Weather Advisories across the Northland was the best course
of action, and the day shift can decide if further action is
needed if they are able to get more confidence in the location of
any snowfall greater than 6 inches. The Advisories were broken up
into three groups based to better reflect the beginning and ending
times of the weather.

This morning: An area of low pressure will be moving east across
far northern Ontario. Southerly flow across the Northland will
bring an influx of warmer and more humid air. The warmer air will
melting some of the snowpack, adding more moisture into the air.
An area of low-level stratus will be lifting from the south into
the Northland, and low-level stratus is in general expected to
develop across the Northland by later this morning. The stratus
could become thick enough to develop some freezing drizzle and
drizzle. Any accumulation should be very light and temperatures
will soon be warming to above freezing, so its impact should be
minimal. However, we will need to monitor conditions for the low
risk of this drizzle developing slippery road conditions for a
brief time this morning.

This afternoon: The stratus should be entrenched across the
Northland by this afternoon, especially across northeast
Minnesota. Temperatures are expected to warm into the middle and
upper 30s over much of the region.

Tonight and Thursday: The low pressure`s cold front will move
through the Northland from northwest to southeast tonight through
early Thursday. The low-level saturated layer will deepen,
creating areas of rain and freezing rain, primarily across
northwest Wisconsin, east-central Minnesota, and up to into parts
of the Arrowhead. A deep, dry mid-level layer should prevent ice
crystal seeding into this lower-level layer, so confident the
precipitation will not be snow quite yet. The snow will spread in
from the northwest along and behind the front later in the night.
This means there could be some icing, up to a tenth of an inch, on
the roads prior to snow getting added on top of the roads.
Temperatures will plummet overnight into Thursday as the snow
spreads through the region. Temperatures will range from middle
20s in the north- central Minnesota to the upper 30s in northwest
Wisconsin near dusk Wednesday, but by later Thursday morning range
from the single digits below zero in north-central Minnesota to
teens and low 20s in northwest Wisconsin. All of the Northland
should be getting snow by dawn Thursday, as well as gusty
northwest winds. There will be periods of low visibility because
of the 20 to 30 mph wind gusts accompanying the falling snow,
playing into what looks like widespread difficult travel
conditions for the Thursday morning commute. The snow will
gradually taper off from the northwest Thursday as colder and
drier air filters into the region. Much of the snow should
dissipate by the middle of Thursday afternoon, but there will be
linger lake effect snow downwind of Lake Superior in northern
Wisconsin into the evening. This latest forecast has widespread
snowfall of 3 to 6 inches across the Northland, with the higher
snowfall totals near the Borderland and downwind of Lake Superior,
where in those areas snowfall could get up to 7 inches. The gusty
winds will continue Thursday, and wind chills will be in the
single digits and teens below zero.

.LONG TERM...(Thursday night through Tuesday)
Issued at 429 AM CST Wed Jan 10 2018

The main concerns for the long term include another shot of
Arctic air and a few snow chances.

With most of the active weather in the short term period, not
much to discuss in the long range. Arctic air will pour into the
Northland behind the departing winter system Thursday night and
Friday. Look for temperatures to trend much cooler once again with
overnight lows dipping into mid single digits to middle 20s below
zero by Friday morning. Wind chills will turn much colder once
again as well, with minimum values between -15 and -35. The colder
conditions continue through the weekend and into next week. Wind
chill headlines will likely be needed for much of the Northland
between Thursday night and Wednesday.

Lake effect snow is expected along the south shore of Lake
Superior. With increasing ice cover over the lake, areas in
Douglas and northern Bayfield County will have a lower chance of
lake effect snow than locations in Iron County. With a drier
upstream airmass for much of the period, think the heaviest lake
effect snow will occur Thursday night, largely ending before 12Z
Friday. Additional snowfall of 1 to 2 inches are expected.
Additional light snow showers are likely through the remainder of
the forecast period, with light accumulation expected.

A quick burst of light snow is possible Sunday afternoon through
Sunday night as an inverted trough moves through the region. Snow
amounts appear light, generally less than an inch for all areas.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 555 AM CST Wed Jan 10 2018

Plume of low MVFR/IFR stratus continues advancing northward under
high altitude cirrus. The leading edge of the lower clouds
stretched from XVG to MZH to near HYR and PBH at 1150 CST and
1300ft ceilings were reported at BRD within the last hour. Think
the stratus will continue to spread northward affecting HYR, DLH,
and HIB within the next hour or two. Lower visibility has followed
the arrival of the stratus by an hour or so. Model soundings
suggest a potential for drizzle/freezing drizzle throughout the
day once the stratus arrives. An area of low pressure will take
shape in Colorado this afternoon and lift through the region by
Thursday evening. A cool front is expected to move southeastward
through northeast Minnesota and into northwest Wisconsin by 12Z
Thursday. Precipitation rates will increase once again this
afternoon in north-central Minnesota and eventually over the
remainder of the area by 12Z Thursday. A mix of freezing drizzle
and snow is expected initially, changing to all snow within an
hour or two for each location. Wind speeds will increase behind
the front raising the potential for blowing snow and further
reductions in visibility. Confidence in this forecast package is
average.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  37  11  13 -12 /  30  80  90  10
INL  34  -1   3 -24 /  40  90  70   0
BRD  37   6   7 -16 /  10  90  80   0
HYR  39  20  22  -7 /  20  90  90  10
ASX  40  22  24  -2 /  10  90  90  60

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...Winter Weather Advisory from midnight tonight to 3 PM CST
     Thursday for WIZ001-006>009.

     Winter Weather Advisory from midnight tonight to 6 PM CST
     Thursday for WIZ002>004.

MN...Winter Weather Advisory from midnight tonight to 3 PM CST
     Thursday for MNZ012-020-021-033>038.

     Winter Weather Advisory from 6 PM this evening to noon CST
     Thursday for MNZ010-011-018-019-025-026.

LS...None.
&&

$$

UPDATE...Huyck
SHORT TERM...Grochocinski
LONG TERM...Huyck
AVIATION...Huyck



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