Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 212209

Area Forecast Discussion
National Weather Service Duluth MN
409 PM CST Sat Jan 21 2017

.SHORT TERM...(This evening through Sunday)
Issued at 408 PM CST Sat Jan 21 2017

It has been an active weather day across the area today, with
temperatures hovering in the middle to upper 30s. An upper level
shortwave is slowly moving north across the region this afternoon,
pushing a wave of precipitation across the area from south to
north today and tonight, before pulling out on Sunday morning.
This feature associated with a surface low that moves northeast
across northern Wisconsin this afternoon and evening, with an
inverted trough extending northwest over northern Minnesota. Lift
is not terribly strong, but enough to produce some light-moderate
precipitation that moves across in waves. Air temperatures have
all risen above freezing as of late afternoon, as have all
available road surface temperatures. However, we are approaching
sunset, and both air and road surface temperatures are going to
fall once again tonight. Expect both to be hovering around
freezing by midnight tonight, which is going to produce new icing
on area roads. This, in combination with the icing that formed
overnight last night is making area roads, especially in the
Arrowhead, treacherous in places, especially back/county roads
that get less treatment, and gravel roads that get little/no
treatment at all. With all this going on have decided to maintain
the winter weather advisory we have out now for the Arrowhead,
that currently runs until 10AM tomorrow. This advisory is
contingent upon getting those colder temperatures though, and we
will have to monitor carefully. We also have a lot of fog over the
area this afternoon, and visibilities should lower once again
after sunset, with some potential for dense fog forming between
sunset and 9PM. With the exact location in question, will leave it
to the evening shift to decide on any needed dense fog advisories.
Sunday the surface low and inverted trough to lift out of the area
and should bring an end to the precipitation, if not the clouds
and fog.

.LONG TERM...(Sunday night through Saturday)
Issued at 408 PM CST Sat Jan 21 2017

A weak short wave trof will move through the forecast area Sunday
night. An embedded impulse will accompany the trof and affect the
area north of the Iron Range. Have low pops for a mix of rain and
snow in the evening, then all snow after midnight. Amounts will be
light as good moisture is lacking. Upper level/surface ridging build
over the region on Monday morning. By afternoon, another trof moves
across the area bringing a slight chance of some rain, mainly east
of Highway 53 and north of the Iron Range. The upper trof departs
Monday night allowing for some ridging to build in. The ridging
holds for Tuesday morning. Tuesday afternoon finds a closed upper
low drifting through the Central Plains and merging with an upper
trof over the Canadian Prairies. It`s associated surface low
meanders around. However, this is where the models begin to differ.
The GFS is baggy and disorganized, the ECMWF has a tightly wound
circulation in the Central Plains, the GEM is farther west than the
ECMWF, the NAM weaker and south. Used a blend of solutions for pops
and ptypes. The model differences persist Tuesday night and
maintained the blended approach to pops/ptypes. Wednesday through
Thursday night features a series of upper level short waves with
embedded impulses driving through the forecast area. These features
will pull cold air from near the Arctic south into the region on a
northerly flow. Have pops to account for this scenario. The
opportunity for lake effect snow begins during this time as well.
However, the depth of cold air is lacking and will impact snow
amounts. Friday finds the final upper trof departing. Even though
the flow will be northwesterly, warm air advection from the
northwest begins to affect the region, along with some ridging.
Temps will remain above normal through Wednesday before returning to
near normal thereafter.


.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1131 AM CST Sat Jan 21 2017

Widespread LIFR is expected to persist through the daylight hours.
The exception will be in the vicinity of showers when conditions
will improve briefly to IFR. After sunset, expect widespread VLIFR
with the light wind and FG/FZFG. Areas of drizzle will occur
periodically through the forecast.


DLH  33  37  31  37 /  50  40  10  10
INL  30  37  28  36 /  30  20  20  20
BRD  32  37  29  36 /  30  20  10  10
HYR  33  39  31  39 /  60  30  10  10
ASX  33  39  31  40 /  70  40  10  10


MN...Winter Weather Advisory until 10 AM CST Sunday for MNZ011-012-



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