Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 141016

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

.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 00Z TAFS through 00Z Saturday evening)
Issued at 843 PM CST Fri Jan 13 2017

Reasoning remains the same as earlier forecast with VFR conditions
expected through the period. The only modification was to delay
the departure of current VFR ceilings across eastern sites to
better line up with observed trends and RAP/HRRR/GLAMP guidance.

KMSP...VFR ceilings will give way to clear skies overnight. No
concerns, and confidence is high overall.

Sunday...VFR. South wind less than 10 kt.
Sunday night...MVFR expected late with a chance of snow or mixed
precipitation. Southeast wind less than 10 kt.
Monday...IFR. Snow likely... mixed precipitation possible.
Southeast wind around 10 kt becoming east.
Monday night...IFR. Snow likely early. Northeast wind 5 to 15 kt
becoming north.
Tuesday...MVFR... IFR possible. Northwest wind 5 to 15 kt.
Tuesday night...VFR. West wind 10 to 15 kt becoming southwest.


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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