Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 170900

Area Forecast Discussion
National Weather Service Duluth MN
300 AM CST Tue Jan 17 2017

.SHORT TERM...(Today through Wednesday)
Issued at 300 AM CST Tue Jan 17 2017

A brief wintry mix for parts of northwest Wisconsin this morning,
but otherwise the quiet weather pattern and gradual warming trend
continues through mid-week.

On the synoptic scale a weak low is moving east across the mid-
Mississippi River Valley while a mid-level shortwave trough drops
out of northwest Ontario into the upper Midwest today. While this
mid-level shortwave trough may contribute to large-scale lift across
northern Wisconsin this morning, impacts will otherwise be fairly
benign with clear skies in the wake of it today. Some stratus will
likely stick around in northern Wisconsin after the precipitation
ends, but as broad ridging develops at mid and upper levels across
the Great Plains into the upper Mississippi River Valley clearing
should mainly prevail. Under clear skies temperatures will fall and
areas of fog will again develop tonight - most likely in northern
Wisconsin but possible anywhere across the Northland. Warm air
advection due to westerly winds through the column tonight into
Wednesday and sunny skies will result in warmer temperatures on

Highs in the low to mid 30s today, with lows falling to the teens
overnight tonight - possibly as cold as the mid-single digits in a
few spots under the clear skies, though a light south-southwest wind
should prevent temps from falling below zero. Warmer Wednesday with
highs in the mid to upper 30s - about 15 degrees above normal.

.LONG TERM...(Wednesday night through Monday)
Issued at 300 AM CST Tue Jan 17 2017

Surface high pressure wil be over the Ohio Valley Wednesday night
through Thursday night. This will leave a ridge axis over the
forecast area with no precipitation. A southwesterly flow aloft will
cover the region. However, temps will start warm with 850mb temps
near 10C Wednesday night, but cooling to around 6C Thursday night.
On Friday, model differences become quite large. The ECMWF has a
horizontal long wave trof from the Northern Plains to the East Coast
by 00Z Saturday, and a surface trof lifting northward through
Minnesota and Wisconsin and across much of the forecast area. The
GFS has a closed mid level low over northern Illinois and surface
ridging still over the region. The GEM is leaning toward the ECMWF,
but is further south and weaker with the upper trof, and further
south with the surface trof over southern Minnesota. Will follow a
blend which leans on the GFS/GEM more than the ECMWF, which is a dry
forecast. The models come together a bit Friday night through Sunday
aloft. However, their locations for the closed upper low/trofs at
about 250 miles apart, with the ECMWF the furthest west. The GEM is
too far to the east and will be discounted. Using a blend of the
GFS/ECMWF gives opportunities for light precipitation through
Monday. Surface temps will be warm enough for light rain during the
day, and a mix of rain and snow in the evening before changing to
all snow overnight. There is a small window for freezing rain late
Friday night, but with the model differences in the thermal profile,
have removed the freezing rain. None of the model soundings support
sleet and have removed. Precipitation amounts will be hard to
discern at this time due to the aforementioned model differences.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1157 PM CST Mon Jan 16 2017

Main concern overnight is fog development at all terminals. Expect
fog to be less dense at KDLH/KHYR due to the high clouds, but will
see visibilities drop to MVFR/IFR or lower. Have a higher
confidence in fog potential and lower visibilities at
KINL/KHIB/KHYR with visibilities as low as LIFR at times.

Brought in a mention of VCSH at KHYR overnight due to the
precipitation closely passing by per the latest obs and RAP/HRRR.
If this activity moves into the KHYR terminal freezing rain will
be a concern. After fog dissipates mid to late Tuesday morning
expect VFR conditions with winds less than 10 knots.


DLH  30  19  34  23 /   0   0   0   0
INL  28  20  35  19 /   0   0   0   0
BRD  30  14  36  22 /   0   0   0   0
HYR  34  17  36  24 /  10   0   0   0
ASX  36  21  38  26 /   0   0   0   0




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