Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 010921

Area Forecast Discussion
National Weather Service Duluth MN
321 AM CST Thu Dec 1 2016

.SHORT TERM...(Today through Friday)
Issued at 320 AM CST Thu Dec 1 2016

Low pressure centered near the Ontario and Quebec border will
move slowly east today into tonight. Cyclonic flow, low level
moisture, and colder air will support light precipitation today
over the Northland. A gravity wave feature was observed along the
North Shore into northern Douglas county as well and the RAP
suggests it will remain in some form today. Moisture was deep
enough into colder air aloft to support mostly light snow early
this morning with surface temperatures warm enough in a few spots
to support light rain or drizzle. We do expect the coverage of the
precipitation to diminish through the day over much of the
Northland. There will be a loss of mid level moisture today into
tonight over portions of the Northland which will cause the
precipitation to mix with or become freezing drizzle or drizzle
where it lingers.

Colder air flowing over Lake Superior will cause lake effect snow to
become more widespread through the day along portions of the South
Shore, continuing into tonight. There may be a mix that occurs
close to Lake Superior due to the warmer lake temperatures. The
low level flow will back this afternoon into this evening to more
northwest which will is less than ideal for lake effect snow over
the snowbelt of Ashland and Iron counties. Snowfall from 2 to 4
inches will be possible today into tonight, mainly over northern
Iron county. There could be some locally higher amounts as well.

Outside of the lake effect precipitation, we expect mainly dry
conditions over the rest of the Northland tonight into Friday. It
is possible there could be some patchy freezing drizzle/flurries
in spots but we don`t think it will be widespread enough to include
at this time.

We expect highs today in the upper twenties to mid thirties with
highs in the upper twenties to lower thirties on Friday.

.LONG TERM...(Friday night through Wednesday)
Issued at 320 AM CST Thu Dec 1 2016

The next weather system to affect the region is progged to traverse
the Upper Midwest late Saturday night and Sunday.  A broad lower
tropospheric warm advection pattern should be the primary forcing
mechanism for ascent and precip production.  There is still no true
arctic air in place this weekend, and thus, temps will be
sufficiently warm that some precip could be in the form of rain
during the day on Sunday.

Short wave ridging then builds briefly into the Upper
Midwest/Western Great Lakes region Sunday night into Monday night as
a low level Pacific-type airmass once again takes up residence over
the region. While we do not have PoPs mentioned during this time
period right now, it is entirely possible that a mention of
drizzle/freezing drizzle/flurries/fog may eventually need to be
added, as low level clouds are unlikely to clear with persistent
weak low level ascent.

Thereafter, the pattern becomes very active for the rest of next
week as the medium range models all suggest that another significant
winter storm will take shape over the middle part of the country
during the Tues-Thurs time frame.  It should be emphasized at this
point that any specific forecasts of snow/ice/blizzard conditions
for any particular area directly from deterministic model data
should be taken with a very large grain of salt, as both the
GFS/ECMWF have exhibited considerable inconsistency with timing and
placement both from run to run and between models.  With that said,
both medium range models seem to be slowly coming to the consensus
that this system will have a deep fetch of quality low level
moisture supplied by 48+ hours of southerly flow northward through
the Mississippi Valley in the warm sector, and an ample supply of
true arctic air flooding southward on the west side of the trof
axis. Typically this time of year, when an amplifying full latitude
trof has these two ingredients to work with, there is often
something quite significant that eventually results.  Therefore,
there is at least some potential for 1) significant snow
accumulations, 2) a band of wintry mixed precipitation, and 3) some
thunderstorms, followed by 4) the first true outbreak of arctic air
across the Northland by the end of next week. Details on the
strength of any potential storm, as well as timing and placement
of precipitation will come into focus over the next few days, and
it will be an excellent idea for anyone with weather interests
across the region to stay current with the latest information over
the coming days.


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1146 PM CST Wed Nov 30 2016

The low pressure system that has impacted the Northland TAF sites
over the past many periods will gradually start to lose its grip
on the Northland over the next day or so. Some snow showers will
continue off and on overnight, and into Thursday, but the trend
will be to taper off with time. Sky cover will be highly variable
with some VFR mixed in with MVFR/IFR. We should see mainly MVFR on
Thursday during the day, along with some VFR. There could be a bit
of patchy freezing drizzle late in the night, especially at KINL
and KHIB, but it is expected to be limited in duration and amount.


DLH  31  26  30  24 /  30  10  10   0
INL  29  24  29  21 /  20  10  10  10
BRD  33  25  29  21 /  20  10  10   0
HYR  34  26  31  24 /  30  10  10  10
ASX  34  29  33  26 /  40  20  10  10




LONG TERM...Miller
AVIATION...DAP is the U.S. government's official web portal to all federal, state and local government web resources and services.