Area Forecast Discussion
Issued by NWS Duluth, MN

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611
FXUS63 KDLH 061217 AAA
AFDDLH

Area Forecast Discussion...UPDATED
National Weather Service Duluth MN
617 AM CST Tue Dec 6 2016

.UPDATE...
Issued at 617 AM CST Tue Dec 6 2016

Please see the new 12Z Aviation Discussion below.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 430 AM CST Tue Dec 6 2016

Early this morning, skies were cloudy across the Northland. An
area of light snow was lifting northward across western Wisconsin,
with visibilities as low as 3/4 mile at KEAU. Across the remainder
of the region, a dry slot had pushed into most areas. Some spotty
light rain or drizzle was reported in some northern locations.
Temperatures had risen into the 30s across most areas of the
Northland, with the warmest reading at the Grand Marais lakeshore
with 41 degrees at 4 am. South winds had started to switch to the
southwest, with gusts well into the 20 mph range.

The focus for today through Wednesday will be trying to time the
various areas of precipitation, as the upper level low lifts
slowly from the Red River Valley into northwest Ontario. The first
main concern will be the area of light snow lifting northward
through western Wisconsin. This area of precipitation will
eventually consolidate and form more of a north to south line that
will affect northern Wisconsin as well as the North Shore of Lake
Superior. High resolution models are giving some impressive QPF to
the North Shore today. An inch or two of snow will be possible in
northern Wisconsin from the morning snow band, with 3 to 6 inches
of snow possible along the North Shore. The heaviest amounts will
definitely be in the higher elevations, as we should see a good
deal of the precipitation fall as rain in the lower elevations
along the lakeshore. Lutsen, Hovland, Tofte, Eagle Mountain and
the Gunflint Trail should see the accumulating snowfall,
especially this morning. Twenty knot onshore winds lifting over
the higher terrain will contribute to those higher amounts. The
RAP and HRRR really hit interior areas of Cook County, with QPF
amounts of one quarter to one half inch or more today.

The focus then shifts to the area of precipitation currently in
the Dakotas, that will wrap into the CWA during the day and into
tonight and Wednesday. Scattered to numerous snow showers will
move in with that feature, as the dry slot is replaced by wrap
around snow showers and deeper moisture wrapping around the
vertically stacked low. We could see an inch or two across much of
the area, and with gusty winds there should be areas of blowing
and drifting as temperatures drop and gusty winds continue into
Wednesday. Temperatures will fall into the 20s for daytime highs.

.LONG TERM...(Wednesday night through Monday)
Issued at 430 AM CST Tue Dec 6 2016

Cutoff low pressure is expected to be centered over northeast
Ontario Wednesday evening and will gradually move eastward into
Quebec by Friday. Northerly to northwesterly flow will develop
behind the departing system with cold air advection continuing.
Abundant low-level moisture over the Northland will maintain the
scattered snow showers through Thursday afternoon. The north to
northwesterly trajectories over a very warm Lake Superior, along
with plenty cloud layer moisture and colder temperatures, will
result in a prolonged period of lake effect snow for northern
portions of Bayfield, Ashland, and Iron Counties. Widespread
accumulation of 3 to 6 inches are expected across those areas,
with more than 8 inches likely for the higher elevation areas of
the Bayfield Peninsula and the Apostle Island, and more than 12
inches expected in the Gogebic Range of northern Iron County. In
coordination with WFO Marquette, opted for a Lake Effect Snow
Watch for the afore mentioned counties from midnight CST Thursday
until 6 PM CST Friday. Snow amounts across the remainder of the
Northland remain in the 1 to 3 inch range during through Saturday
morning.

Lake effect snow will gradually diminish as winds back westerly
Friday night and Saturday ahead of the next storm system
approaching for the second half of the weekend. Deterministic
models are similar enough to support a chance of snow across the
area Saturday night and Sunday. While the guidance has produced a
system moving through the Upper Midwest this weekend over several
runs, kept POPs in the "chance" category for now. The evolution of
the earlier departing low will have affects on the track and
intensity of that system.

Temperatures will trend colder through the long term with daytime
highs in the teens and 20s Thursday, dipping into the single
digits to teens Friday and Saturday, and single digits to 20s
early next week. Overnight lows will range from either side of
zero to the low teens. The overall temperature trend continues to
point to below to much below normal temperatures through the
extended.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 617 AM CST Tue Dec 6 2016

Cutoff low pressure over northwest Minnesota this morning will
wobble eastward across northern Minnesota and into Ontario by
tonight. Snow showers are expected this morning over northwest
Wisconsin, including HYR, and a rain/snow mix with moderate snow
at times is expected for far northeast Minnesota including TWM,
BFW, and CKC. Drier stratospheric air is descending into central
and north-central Minnesota affecting BRD/HIB/INL. A few pockets
of -FZDZ or -SN may affect INL during the next few hours. Mainly
MVFR ceilings are expected through the forecast period, although
BRD and HIB may scatter out to VFR later this morning or early
this afternoon. Wrap around light snow will move into the
terminals once again tonight as the low moves across northeast
Minnesota. Trended toward lower half MVFR ceilings, but could
certainly see a period of IFR CIGS overnight. Confidence in snow
intensity and associated visibilities is below average this
morning, so opted for MVFR VSBYS except at BRD, where stronger
winds and slightly higher snow intensity will result in IFR
conditions. As the upper low moves over the area tonight, there is
a potential for low-level wind shear. The greatest potential will
be at INL/HIB/BRD overnight. Maintained gusty wind character in
lieu of LLWS for now. Overall confidence with this forecast
package is average.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  26  15  21  18 /  50  30  30  40
INL  25  19  27  18 /  60  60  60  50
BRD  24  14  19  15 /  60  30  30  40
HYR  30  16  21  18 /  70  30  30  40
ASX  34  20  24  21 /  70  30  30  50

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...Lake Effect Snow Watch from late Wednesday night through Friday
     afternoon for WIZ002>004.

MN...Winter Weather Advisory until noon CST today for MNZ012-020-021.

LS...Small Craft Advisory until 3 PM CST this afternoon for LSZ121-
     140>148.

     Gale Warning from 3 PM this afternoon to 9 AM CST Wednesday for
     LSZ121-140>148.

&&

$$

UPDATE...Huyck
SHORT TERM...DAP
LONG TERM...Huyck
AVIATION...Huyck



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