Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 181716

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1116 AM CST Thu Jan 18 2018

.updated for 18z taf discussion below...

.SHORT TERM...(Today and tonight)
Issued at 400 AM CST Thu Jan 18 2018

Upper level wave continues dropping southeast across northern
Minnesota early this morning.  IT`s trajectory will take it through
northern Wisconsin and the Upper Peninsula of Michigan as it
continues eastward, keeping any light snow to our north and east. We
will however see cloudy skies for a few hours this morning as the
wave slides by, but skies should clear for many by sunrise.

Once the clouds depart to the east early this morning, expect a
sunny and warm day.  Southwest winds of 5 to 15 MPH are expected,
with the Buffalo Ridge seeing stronger winds and downsloping leading
to temperatures rising into the 40s.  The remainder of the area will
see temperatures top out in the mid to upper 30s under bright

With the upper level ridging in place and relative warm airmass,
temperatures will bottom out in the mid to upper 20s overnight which
is well above normal for this time of year.

.LONG TERM...(Friday through Wednesday)
Issued at 400 AM CST Thu Jan 18 2018

The main focus is on the Sunday-Monday time period as it continues
to look like a strong low pressure system could bring a wintry mix
and accumulating snow to the upper Midwest.

The upper trough is still west of the CONUS at this time.  The main
upper trough is expected to push ashore Friday Night and lead to
surface cyclogenesis along the lee of the Rockies Saturday.  This
system resembles a panhandle hooker archetype; with the surface
cyclone dropping south across the panhandle region before curling
northeast through the Upper Midwest, pulling gulf moisture northward
as it continues to deepen on its journey northward.  This system
will have impressive forcing leading to strong lift and ample
moisture.  It will also bring strong winds, especially on the cold
side.  The big question is always determining the track of these
types of systems.  The guidance didn`t change much from yesterday,
but when looking at all the ensemble members and the deterministic
solutions, slight shifts in the track continue from run to run.

The GEFS ensemble continues to aim the highest probs of significant
accumulation from southwest MN through northwestern WI.  However,
there is still a large degree of spread in the members in terms of
QPF and Snowfall potential, so uncertainty remains high.

Similar to yesterday, followed a blended guidance approach which
raised PoPs into the 80% range.  We also raised wind speeds above
the blend given the deepening surface cyclone expected nearby.
Blizzard conditions still appear possible for areas that receive
significant snow accumulation.  The next few days will be rather
warm, so our current snowpack will likely crust over.  Keep up to
date with the latest forecasts as we get closer to Sunday/Monday.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1115 AM CST Thu Jan 18 2018

VFR through the period. Some high clouds moving across the area
this afternoon. Perhaps lowering to 15000 ft later tonight into
Friday. SW-S winds 10kts or less through the period. additional concerns.

Fri night...VFR. Wind SW at 5-10 kts.
Sat...VFR. Wind light and variable.
Sun...VFR early, IFR or lower with SN or wintry mix likely Sunday
night. Wind NE 5-15 kts.&&



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