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Area forecast discussion 
National Weather Service North Platte NE
322 am CST Sat Dec 27 2014

issued at 320 am CST Sat Dec 27 2014

Water vapor imagery and the 08z mean sea level data showed that the cyclone had
moved into Iowa with the front trailing through eastern Kansas and
eastern Oklahoma to southwest Texas near The Big Bend region. The
radar loop indicated snow in central and north central Nebraska
decreasing in coverage and extent. Surface temperatures in northeast
Alberta and northern Saskatchewan were 15-25f below zero.


Short term...(today and tonight)
issued at 320 am CST Sat Dec 27 2014

Snow in central and north central Nebraska will end by 15z with
little or no additional accumulation after we will let the
Winter Weather Advisory expire as it is. Then...with moderate snow
cover over the area...radiational heating will be minimal and cold
temperatures can be expected today with highs in the 20s. With clear
sky and light wind tonight...lows will range from below zero in the
Platte River valley to near 10 in north central Nebraska.

Long term...(sunday through friday)
issued at 320 am CST Sat Dec 27 2014

Upper level ridge amplifies over the far eastern Pacific during the
extended period...setting the stage for an Arctic plunge and another
chance for snowfall early next week as a large trough digs south
into the western two thirds of the Continental U.S.. Sunday will still have
temperatures in the 20s and 30s out ahead of a southward advancing
cold front. Models are coming to a better consensus on the timing of
the frontal passage and have slightly slowed...bringing the front into the County Warning Area
during the Sunday night period. Temperatures through the day Monday
will likely ignore a typical diurnal pattern in the presence of
strong cold air advection...holding steady or slightly falling in the single digits
and low teens through the day. Blustery north winds will combine
with the Arctic air to create bitterly cold wind chills readings.
Wind chills will remain below zero for the daylight hours
Monday...then exceeding Wind Chill Advisory criteria across most of
the County Warning Area for Monday night as lows fall into the -5 to -15 range and
resulting wind chill values at or below -20. Wind chill headlines
will likely be needed early next week to address this concern.
Given a 1056mb or stronger Arctic high pressure dropping southeast
along the eastern rockies and our widespread fresh
snowpack...temperatures could be much colder than currently
forecast. However abundant cloud cover should keep temperatures from
completely falling off...relatively speaking.

850 mb temperatures bottom out at -15c to -20c Tuesday afternoon. Surface temperatures
will struggle to get into the single digits in some areas. Winds
will not be as strong on Tuesday as the surface high pressure moves
closer to the County Warning Area...but will be enough to keep wind chills in the
single digits below zero through the day. Tuesday night has the
makings of a very cold night as the surface high pressure settles into
western Nebraska...however cloud cover could once again limit
radiational cooling despite the favorable surface conditions. Did not
have the confidence to undercut min T guidance at this time.

As for wintry precipitation chances...areas of light snow and
blowing snow should develop behind the cold front as it moves
through Sunday night. Probability of precipitation linger through Monday as the lead pv maximum
approaches the County Warning Area from the southwest. Kept quantitative precipitation forecast amounts light and
probability of precipitation in the 30 to 40 percent range since the cold and moisture
starved airmass will likely limit snowfall amounts and coverage.
BUFKIT analysis and Cobb tables suggest the potential for higher
than climatology slr...however strong winds should work to limit slr
through compaction. Kept total amounts at 2" or less with the
highest amounts generally north of Highway 2.

Temperatures begin a slow rebound on Wednesday as the upper level
low cuts off in the southwest Continental U.S. And heights rise across the
central and Southern Plains. The closed low is slowly absorbed back
into the mean northern stream as another shortwave trough dives
south out of Canada by the end of next week. This may bring another
chance of snow to the area...but confidence in the model solutions
is too low to say anything for certain at this time.


Aviation...(for the 06z tafs through 06z Saturday night)
issued at 1126 PM CST Friday Dec 26 2014

For both the klbf and kvtn terminals...light snow will come to an
end across western and north central Nebraska by 09z overnight.
Through this time...visbys down to 4sm and ceilings around 3000 feet above ground level
are expected. Skies will begin to clear toward sunrise Saturday
morning with clear skies expected thereafter. Winds will be from
the northwest or west at around 10 kts through 00z
Sunday...decreasing to under 10 kts Saturday evening.


Lbf watches/warnings/advisories...
Winter Weather Advisory until 4 am CST early this morning for



short term...Springer
long term...Martin

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