Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Goodland Kansas
1215 am MST Sat Dec 27 2014
issued at 815 PM MST Friday Dec 26 2014
Update has been issued to cancel Winter Weather Advisory and
remove enhanced wording in forecast pertaining to the advisory.
Radar trends have showed areal coverage of precipitation has
dropped off sharply with upper low finally shifting more into the
plains region...and off the Front Range/rockies. Still do expect
some light scattered accumulate over the next several hours as return
backside flow from this system affects the region. The trend for
later tonight is for gradual clearing...and is showing up well on
satellite loop. So...for rest of evening before clearing
ensues...up to an additional inch of accumulate is possible with temperatures
still looking to drop sharply as skies become more clear and
radiational cooling ensues...with fresh snowpack in many spots.
Short term...(this afternoon through saturday)
issued at 100 PM MST Friday Dec 26 2014
At 18z upper low center located over the western slope of Colorado
with broad area of light snow over all of the forecast area except
roughly east of a line from Oberlin to Colby and Leoti where
700-500mb relative humidity rather low.
For the rest of the afternoon upper low opens up a bit while
lifting northeast across the area with initial dry slot over the
far east saturating thus light snow commencing.
For the evening and overnight hours...upper trough continues
moving northeast with some drier air coming into the southeast and
southern sections of the area bringing an end to the snowfall.
North of this line some light snow still expected with minimal
accumulation. After midnight no precipitation expected as low and
middle level moisture exit the area. Low temperatures generally in
the single digits above zero. Low teens from Norton to Oakley and
Leoti and points east.
Saturday...lots of sunshine with northwest winds around 10 miles per hour in
the morning backing to the west by afternoon then southwest/west
late in the day. Forecast challenge will be temperatures.
Anticipating areas generally along/north of the Interstate to have
highest snowfall totals and depths with lesser amounts to the
south. Despite full sunshine snowpack will prevent full mixing and
will aim for highs in the middle 20s to around 30. South of the
Interstate am expecting low 30s.
Long term...(tuesday through next saturday)
issued at 1208 am MST Sat Dec 27 2014
Light snow will continue through Tuesday as bitterly cold Arctic
air settles into the region. Soundings are entirely -12c or colder
so there will be no threat of freezing precipitation. Snow amounts
will be very light however. Although wind speeds are relatively
light...Wind Chill Advisory (-15f) or warning (-25f) criteria will
likely be reached Tuesday and Wednesday. Shortwave ridging
Wednesday and Thursday will result in dry conditions and some
modest warming but still below normal temperatures. Latest run of
the GFS brings the closed low out of the Desert Southwest late in
the week a little further north...but European model (ecmwf) still has it south so
will only carry slight chance probability of precipitation for snow at this point. Another
shot of colder air will follow behind that system to start next
Aviation...(for the 06z tafs through 06z Saturday night)
issued at 1027 PM MST Friday Dec 26 2014
For both taf sites...mainly VFR conditions with bkn050-100 through
12z Sat...then sct050-100. From 07z-09z though MVFR -SW with visibility
down to 4sm at times. Winds north-northwest 5-10kts through 18z Sat...then west-southwest