Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 141705

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1105 AM CST Sat Jan 14 2017

.updated for the 18z aviation discussion below...

.SHORT TERM...(Today and tonight)
Issued at 416 AM CST Sat Jan 14 2017

It will be a quiet short term period with high pressure in control.
This will result in a beautiful January day to get out and enjoy
some outdoor winter activities, with sunny skies, light winds, and
highs around 20. For highs today, not seeing much spread in the
guidance, so basically went with a blended mean for highs today. Not
much is expected to happen tonight either, though clear skies and
light winds will allow us to see lows down in the single digits
(near normal) before the warm up really starts to get going on

.LONG TERM...(Sunday through Friday)
Issued at 416 AM CST Sat Jan 14 2017

The main concerns in the long term continue to revolve around the
storm system for Sunday night-Tuesday and the January thaw mid to
late next week.

We have seen some improvement with the 14.00z model run regarding
the large scale details of the upcoming system. Namely the
differences regarding how northern and southern streams were
going to join up have resolved notably. Overall models are honing
in on less phasing and therefore allow for a more progressive
system. This gives increased confidence regarding timing of precip
chances, and indicates most precip should be ending by late
Tuesday morning.

Conversely, what has not improved with the models this morning is
agreement on how much warm aloft will be drawn into the area. The
14.00z GFS was the coldest and featured nearly all snow for our
area, with a swath of 4-6 inches stretching from southwest MN
across the Twin Cities into west central WI. However, the GFS is
viewed as the outlier, with the ECMWF and NAM featuring more of a
freezing rain scenario with 1-3" amounts in addition to the
freezing precip. If the latter scenario holds true, a good chunk
of south into east central MN and west central WI will be in
jeopardy of quarter inch ice accumulations on Monday. Given these
factors, have issued a winter storm watch for the heart of the
forecast area. May need to extend this farther east/southeast to
include west central WI if the freezing rain threat holds with
subsequent model runs.

Wednesday and Thursday look to feature quiet weather with
moderating temperatures. By Thursday afternoon highs in the mid to
upper 30s look common. The warming trend in temperatures will be
associated with mid level ridging building into the central CONUS
as a trough deepens over the west coast. Eventually the GFS
forecasts the trough to induce surface cyclogenesis over the Texas
panhandle and lift a surface low north to Lake Superior by 12z
Saturday. The ECMWF keeps the surface trough across the southern
CONUS but does allow for some northern stream energy to generate
light precip on Saturday. Definitely looks like another mixed
precipitation potential, although more of a rain-snow scenario
given warmer surface temps.


.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1105 AM CST Sat Jan 14 2017

VFR through period. Winds light west becoming more southerly as
high retreats to the east into Sunday.

VFR no concerns.

Sun night...VFR. Winds S 5 kts.
Mon...MVFR/IFR. -SN likely with chance of -fzra/-IP Monday
morning. Winds SE 4 to 7kt.
Tue...VFR. Winds NW bcmg W 5 kts.


MN...Winter Storm Watch from Monday morning through Tuesday morning
     for MNZ051>053-058>063-065>070-075>077.

     Winter Storm Watch from late Sunday night through late Monday
     night for MNZ073-074-082>085-091>093.



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