Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 200554

Area Forecast Discussion
National Weather Service Duluth MN
1254 AM CDT Thu Oct 20 2016

.SHORT TERM...(This evening through Thursday)
Issued at 334 PM CDT Wed Oct 19 2016

A cooler Canadian airmass will gradually advect across the upper
Midwest into the upper Great Lakes today and tomorrow leading to
cooler conditions. In addition, mid-level moisture associated with
the cooler air will lead to cloudy skies and a chance for showers
(or more like flurries/sprinkles) across the international border

On the synoptic scale an upper low over northwest Ontario is
gradually weakening, soon to be absorbed by a deep longwave trough
that will develop across the Mississippi river valley late tonight
into Thursday. As this happens, cooler air will advect across
northern Minnesota and northwest Wisconsin tonight into Thursday.
Not an incredibly cold airmass (850mb temps around -5C) but
seasonably cool. With this cooler air will also come a stream of
fairly deep moisture bringing cloud cover and possibly some light
precip given the bit of instability introduced by the cooler air
aloft. The 12z sounding upstream at CYQD (The Pas) in northern
Manitoba shows a surprisingly saturated profile through about 300mb,
and combined with the already stubborn stratus that held on today
across the Northland expect showers will be possible. A few sites
across northwest Ontario have reported light rain or snow today, so
went a bit aggressive on the precip chances up north (north of the
Iron Range), with a buffer of sprinkles/flurries. There`s even a
possibility for some lake enhanced showers along the south shore -
mainly across the Bayfield Peninsula.

Tonight...look for some clearing skies as an area of drier air moves
in across northern Minnesota. Lows in the low 30s, with a few
locations possibly dropping into the upper 20s. Calm wind.

Thursday...increasing clouds with a chance for rain/snow showers
and/or sprinkles/flurries, mainly along and north of Iron Range.
Highs cool in the low to mid 40s, which is only about 5 degrees
below normal.

.LONG TERM...(Thursday night through Wednesday)
Issued at 334 PM CDT Wed Oct 19 2016

The upper level trough over the western Great Lakes will move off
to the southeast Thursday night, as upper level ridging moves into
the region on Friday. A weak shortwave will ride along the upper
level ridge Friday and Friday night bringing a chance of showers
to northern areas by Friday night. Warmer air will gradually
return for the weekend, although the models do start to show some
differences as early as Saturday. The big story is the potential
development of a major upper level system from the early to middle
part of next week. The ECMWF is most dramatic with widespread
precipitation expected to move into the region from Monday night
into Wednesday. The GFS keeps most of the precipitation south of
the CWA during that time. Will also maintain a chance of thunder
across southern portions of the Northland from early to midweek
next week. High temperatures will rise from the 40s on Friday, to
the 50s over the weekend and into next week.


.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1254 AM CDT Thu Oct 20 2016

A trough axis will dig southeastward from southern Saskatchewan
into western Upper Michigan by the end of the forecast period per
the latest guidance. This will generally keep MVFR/VFR ceilings
through the forecast. All terminals, except for INL, will see
ceilings flirt with MVFR with ceilings around or just above 3000
ft. Still uncertain how widespread shower activity will be
tomorrow, but think the latest GFS/ECMWF have the best handle on
the situation. Used this guidance for VCSH mention at INL/HIB.
May need to expand VCSH to DLH in future updates if guidance
trends towards the GFS/ECWMF. Winds will remain less than 10 kts
through the forecast.


DLH  30  44  31  46 /   0   0   0   0
INL  32  41  29  47 /  20  30   0  10
BRD  31  45  30  51 /   0   0   0  10
HYR  31  46  30  48 /   0   0   0   0
ASX  35  46  32  47 /   0  10   0   0




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