Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 122130

Area Forecast Discussion
National Weather Service Duluth MN
330 PM CST Tue Dec 12 2017

.SHORT TERM...(This evening through Wednesday)
Issued at 328 PM CST Tue Dec 12 2017

At 3 PM, light snow was falling across much of northeast
Minnesota. Snowfall amounts up to this point have been light based
on reports and a survey of web cams across the area. Much of the
moisture at this point has gone into saturating the drier low
levels of the atmosphere. Temperatures ranged from the single
digits in the Minnesota Arrowhead to the teens elsewhere.

The focus for tonight and Wednesday will be the evolution of the
incoming clipper system. While the models are generally in decent
agreement, there are some differences in synoptic and mesoscale
handling of the system. The initial band of light snow will
continue to move eastward across the region late this afternoon
and evening, helping to saturate the low level environment. The
question is with regard to where the main axis of precipitation
will pivot across the region. The HRRR supports more of an
opportunity for snow accumulation than the NAM for the
Duluth/Superior area. Nearly all of the deterministic models
support a solid advisory across the Minnesota Arrowhead, so we did
issue an advisory for the entire Arrowhead starting at 9 pm
tonight and ending at 4 pm Wednesday. Easterly winds will likely
contribute to locally higher amounts, up to 6 inches in spots.

Based on current thinking, we should see a widespread swath of 2
to 4 inch snow accumulation from north central Minnesota, near the
International Border, down through the Twin Ports and into
northern Wisconsin. The greatest amounts are expected further
east. Duluth is still a bit of a tricky one, as some of the models
only support about an inch of snow, while others would indicate
the 2 to 4 inches. So we should fall somewhere in that range.
Generally expecting a couple here. The least snow accumulation is
expected in the Brainerd Lakes, although they are the ones that
may see a bit more mixed precipitation, and possible freezing
drizzle overnight and early Wednesday.

Will issue an SPS for areas outside of the advisory, and would not
be surprised to see some modifications to the current advisory for
the overnight hours into Wednesday due to the possibility of mixed
precipitation and some west to east convective banding. We may
need to expand the advisory beyond it`s current area, but will
start with the most likely scenario at this point.

The precipitation focus will then shift southward on Wednesday, as
the low slides southeast, and brings the main area of wrap around
precipitation southward with it.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 328 PM CST Tue Dec 12 2017

The persistent northwest flow of the past seven days will finally
give way to a small pattern change late-week into the weekend
leading to slightly warmer temperatures this weekend into early next
week. A continued chance for snow showers most days through the long
term period, with the best chance for accumulating snow Friday night
into Saturday when around an inch or so is possible. Highs in the
teens to 20s through the rest of the week and into the weekend, then
warmer Monday with highs in the 30s across much of the Northland.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1121 AM CST Tue Dec 12 2017

VFR conditions today will gradually diminish to MVFR ceilings and
visibilities this evening through mid-day Wednesday with some
ceilings becoming IFR after midnight tonight. Snow will reduce
visibility to MVFR conditions but periods of IFR visibility will
be possible with the more intense bands of snow. In addition to
the snow, there may be periods of freezing rain/drizzle at BRD,
HIB, and DLH overnight with a light ice accretion (up to a tenth
of an inch) possible. Light northwest winds around 5-10 knots
today will become south-southeasterly overnight tonight, then more
easterly towards Wednesday morning.


DLH  12  22   9  19 /  70  80  20  10
INL  12  20   5  15 /  80  70  10  20
BRD  19  27  13  22 /  40  30  10  10
HYR  11  21  10  20 /  70  80  40  20
ASX   8  22  13  20 /  80  90  70  30


MN...Winter Weather Advisory from 9 PM this evening to 4 PM CST
     Wednesday for MNZ012-020-021.



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