Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Twin Cities/Chanhassen Minnesota
1050 PM CST Sat Feb 13 2016
Short term...(this evening through sunday)
issued at 300 PM CST Sat Feb 13 2016
This afternoon...all attention is on a shortwave currently advancing
east through Montana. This feature will continue on southeast
trajectory through the night and Sunday. This will lead to a decent
warm air advection/isentropic lift focused snow event...which will mainly impact
the area highlighted by the Winter Weather Advisory from North
Dakota through eastern South Dakota...western Minnesota...and Iowa. Not a
lot of changes were made to the going forecast for this period as
the Winter Weather Advisory that was issued by the midnight shift
overnight still looks to be in good shape.
The hi-res cams came in support of the advisory area...and cutting
back somewhat on the quantitative precipitation forecast in eastern Minnesota through western WI. The
strongest forcing still looks best across western Minnesota through south
central. The adiabatic Omega on the 285k surface reflects this area
well...broad lift through that area with weaker lift to the north
and east including the metropolitan. In terms of upper level
support...nothing too impressive here but the support that is there
is centered over that same area from eastern South Dakota through western and
far southern Minnesota...through Iowa. In terms of timing...slowed things
down an hour or two...as the cams indicate the precipitation crossing into
western Minnesota after 00z. One concern we do have with the cams is the
arw and namnest really shut off the snow tomorrow middle morning across
the area. With the secondary upper level feature pushing
through...still expect light snow to be falling for this morning
period. Overall...quantitative precipitation forecast in the west and south looked remained mostly
consistent...while we did trim the amounts in the east.
There will be some decent southeasterly winds while this snow is
falling so visibilities will likely be reduced...significantly at
times...primarily in the advisory area. Wind speeds of 20 miles per hour with
gusts to 30 miles per hour in moderate snow will cause difficult travel
conditions in this area.
Long term...(sunday night through saturday)
issued at 300 PM CST Sat Feb 13 2016
Light snow will end Sunday night across eastern Minnesota and western WI
as an upper trough over the local area pushes east. Any additional
snow accumulation will be a half inch or less.
The theme for next week is warmer temperatures...especially during
the latter half of the week. There is one dip in the Road and
that is Tuesday night and Wednesday when another surge of Arctic
air will give the local area a glancing blow. Prior to
this...another wave of low pressure will move southeast from the
Dakotas to Iowa Monday night and Tuesday. Model agreement today is
much better with this feature over what we experienced yesterday.
All solutions now keep the bulk of this system to the west and
south of the forecast area.
A much warmer southerly flow will envelop the area from Thursday
into Saturday. Some light wintry precipitation is possible
Thursday night to the north and east of the Twin Cities as a warm
front moves through with a chance for some light rain across the
area on Friday.
Highs for Monday and Tuesday will be near the freezing mark...fall
to the lower and middle 20s for Wednesday...then rebound into the
upper 30s to lower 40s for Thursday through Saturday.
Aviation...(for the 06z tafs through 06z Sunday night)
issued at 1050 PM CST Sat Feb 13 2016
Snow will move will move across Minnesota from west to east
tonight and should be to the Minnesota/WI border by around sunrise. The
highest snow totals will occur across western and southern Minnesota.
Light snow or flurries will linger for most of the day tomorrow
with MVFR/IFR conditions. There could be a second batch of light
snow with 3-5sm visibility late tomorrow afternoon and tomorrow
it looks like the best chance for 0.5"-1.5" of accumulation will
be early tomorrow morning...with a decrease in snow intensity by
middle to late morning. The snow might come to a stop in the
afternoon...with another period of light snow in the early
evening. The more persistent snow bands should remain well south
and west of the Airport.
/Outlook for kmsp/
Monday...MVFR/VFR ceilings. Wind west 10 knots.
Tuesday...MVFR/VFR with -sn possible. Wind northwest 10 knots.
Wednesday...VFR...lingering MVFR possible. Wind east-southeast 5 knots.
Minnesota...Winter Weather Advisory until noon CST Sunday for mnz047-054>057-