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Area forecast discussion 
National Weather Service Twin Cities/Chanhassen Minnesota
550 am CST Thursday Dec 25 2014

Short term...(today and tonight)
issued at 322 am CST Thursday Dec 25 2014

The short term concerns remain snow threat across central Minnesota
during the period.

Models still indicate at least a narrow band of light snow across
the area. This is focused along a line from near Madison and
Appleton to near St cloud. Perhaps an inch indicated by St cloud
with 2 to 3 inches out toward west central Minnesota by Friday morning.
Jet streak induced forcing rides off to the east later today as the
northern stream jet axis lifts off. Temperatures forecast to rise
into the middle to upper 30s again over the southern County Warning Area...ahead of the
cold front. With strong forcing...could see some drizzle/light rain
mixed with snow on the southern fringe of the snow area during the
day.

Then forcing refocuses during the night as the southern stream jet
noses northeast into Iowa focusing frontogenetic forcing behind surface
front. Small chance of some freezing drizzle developing into the
southeast quadrant of the County Warning Area into tonight as ice is not introduced
into the cloud layer.

Long term...(friday through wednesday)
issued at 322 am CST Thursday Dec 25 2014

At the start of the long term forecast period...the large scale pattern
will feature a shortwave trough over The Four Corners region of
the southwestern Continental U.S....and a northern stream cyclone over
northern Manitoba. Shortwave energy ahead of The Four Corners
trough will stream northeast into the area on Friday. Overcast
skies will persist...while low level lift provides the support for
light precipitation. Still looks like periods of freezing
drizzle/drizzle may accompany the light snow for at least a
portion of the area...given the absence of persistent upper forcing.

On Friday night...stronger/deeper forcing arrives as the southwest
Continental U.S. Trough ejects northeast into the area. This should turn any
mixy precipitation over to snow...with southern Minnesota and WI
appearing to have the highest probability of precipitation. Looks like areas along and
east of a Redwood Falls to Twin Cities to Rice Lake Wisconsin line
could see one to two inches of new snow between 00z and 18z Saturday.

Over the weekend...the shortwave energy of southern stream origin
gets absorbed into the northern stream...and the flow pattern
locally becomes more zonal. As the aforementioned northern stream
energy tracks across Quebec...cold high pressure infiltrates the
northern Continental U.S. Early next week. By late Monday...850 mb temperatures lower
to around -20c...which indicates highs Tuesday and Wednesday will top
out in the single digits across much of the area. Could see some
light snow on Monday as the Arctic boundary settles into the area.

&&

Aviation...(for the 12z tafs through 12z Friday morning)
issued at 517 am CST Thursday Dec 25 2014

IFR ceilings/low end MVFR ceilings remain over over most of the area. VFR
did materialize over the southwest and this may continue for a few
hours before snow fills in over the west into central...affecting
mainly kstc and just north of kmsp through 18z. After 18z...the
snow may work farther south. The 06z model trended a bit farther
south with the snow band during the day. This works south overnight
into Friday. MVFR ceilings lower again overnight to IFR...mainly
after 06z. The probability for snow is too small to add at this
time. SW-S winds becoming north-northwest with passage of the
front...generally less than 10kts.

Kmsp...low end MVFR ceilings remain this morning. The 06z models
trended a bit farther south with the snow band. Will have to
monitor this but included prob30 after 21z for now. Then ceilings
lower to IFR overnight as the cold front passes with cold air advection behind
the front. S-SW winds becoming north with the passage of the
front...generally less than 10kts.

/Outlook for kmsp/

Friday night...MVFR/IFR with chance -sn. Winds north-northwest 10 kts.
Sat...VFR. Winds west-northwest 5-10 kts.
Sun...VFR. Winds south-southeast 5 kts.

&&

Mpx watches/warnings/advisories...
Minnesota...none.
WI...none.
&&

$$

Short term...dwe
long term...ls
aviation...dwe

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