Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 221800

Area Forecast Discussion
National Weather Service Duluth MN
100 PM CDT Sat Oct 22 2016

Issued at 100 PM CDT Sat Oct 22 2016

Updated for the new 18Z Aviation Discussion below.


.SHORT TERM...(Today through Sunday)
Issued at 305 AM CDT Sat Oct 22 2016

A trough of low pressure extended south from the Ontario and
Manitoba border through western Minnesota early this morning. Warm
air advection and a shortwave ahead of this feature was aiding in
producing clouds and some light rain or sprinkles over the eastern
third of the Northland. An upper level ridge will shift east today
bringing an end to the threat of rain this morning. Clouds will be
on the decrease and highs will be in the fifties.

Tonight, a shortwave will move into the area with a surface low
moving from the Dakotas into east central Minnesota by 12Z Sunday.
The best lift will be north of the low and this is where we have the
highest chance for precipitation tonight. The low will continue
southeast through the day Sunday moving through southern Wisconsin.
There will be a chance for mainly rain along and north of the low
track, with the highest chance over far northern Minnesota Saturday
night into in northern Minnesota to far northern Wisconsin Sunday
morning. Soundings suggest the precipitation will be all rain but
the NAM does show some weak CAPE so if there is some convection that
does develop a brief mix will be possible in spots in northern
Minnesota. At this time, the most likely scenario is for light rain
to occur and we will keep just rain in the forecast. The chance for
rain will diminish from west to east through the day Sunday as high
pressure starts to build in. Sunday will be cooler, especially over
the north where highs will only be in the lower to middle forties.
Southern areas from the Brainerd Lakes east across northwest
Wisconsin will be in the lower to middle fifties.

.LONG TERM...(Sunday night through Friday)
Issued at 305 AM CDT Sat Oct 22 2016

Surface high pressure builds across the forecast area Sunday night
and remains nearby through Monday night. Tuesday finds a mid level
ridge over the area. Meanwhile, a surface low is organizing in the
Central Plains. Warm air advection is underway and moisture is
returning to the region. All models bring some upward vertical
motion over the southern edge of the region in varying degrees. This
affects the onset of rain in this portion of the forecast area. As a
result, have dialed back on the pops in the morning and have them
aligned over the southern half of the forecast area by afternoon.
The surface low moves into Iowa Tuesday night accompanied by an
upper level trof. Meanwhile, surface and upper level ridging is in
charge over the northern half of the region. Will keep the highest
pops over the southern half of the area nearest the best forcing
which is over southern Minnesota. Wednesday through Friday finds the
models offering two very different solutions and how they affect the
region. The GFS establishes upper level and surface ridging through
Friday, the ECMWF brings a digging upper level trof and its surface
low through south central Canada through Wednesday night before
merging with a cut off upper low over the eastern Great Lakes. The
amount of cold versus warm air is different as well and affects the
precipitation type. Leaned toward the warmer temps of the GFS which
leads to all rain. Used a blended approach though for pops to
resolve these differences.


.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 100 PM CDT Sat Oct 22 2016

High pressure over eastern Minnesota and western Wisconsin is
providing very light wind speeds and mostly clear skies this
afternoon. There will be increasing high clouds later this
afternoon and into this evening, from the northwest, as an area of
low pressure approaches as it moves through the Dakotas. The low
will move through central Minnesota into west-central Wisconsin
late tonight and Sunday morning. Associated light rain is likely
across far northern Minnesota, primarily for KINL and KHIB. Even
lower ceilings will develop Sunday morning in the cooler and
northerly flow in the wake of the passing low. The KINL area will
likely have a period of MVFR ceilings, and KHIB could flirt with
MVFR too.


DLH  56  40  50  33 /   0  20  50   0
INL  50  38  46  32 /  10  60  60   0
BRD  59  40  53  33 /   0  10  10   0
HYR  58  38  54  32 /   0  10  20   0
ASX  57  40  52  35 /   0  10  50   0




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