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Area forecast discussion 
National Weather Service Goodland Kansas
427 am MST Monday Dec 29 2014

Short term...(today through Wednesday night)
issued at 239 am MST Monday Dec 29 2014

Areas of fog developed along and north of Interstate 70 this
morning with visibilities between one quarter and one mile. Satellite
fog product shows the fog in the far northwest corner of Kansas...and
it is expanding to the south and east. Will continue to mention
fog through the early morning.

Arctic front is poised to sweep across the forecast area today.
Expect the front to be along the Kansas/Nebraska border by 12z...south
of Interstate 70 by 15z...and through the entire area by 18z. 00z
upper air analysis showed 850 mb temperatures across Montana/North
Dakota around -14 degrees the air mass is certainly

Short term models are in good agreement in developing snow over the
entire area after 18z today...though there is disagreement on
amounts. Differential cyclonic vorticity advection will occur at
various times through the 30 hour period. 300 mb jet of 140 knots
will be near the area late tonight. 00z GFS is more aggressive
than previous runs...though not as moist as the NAM. GFS low layer
q vector convergence and frontogenesis are better than previous
model runs. Winter weather analogs continue to support a 2-4 inch
forecast through Tuesday with lower amounts east of Highway 83 and
higher amounts in eastern Colorado. This is reasonable...though
would like to see better isentropic upglide and higher precipitable
water values. With this cold of air is
unreasonable to expect high precipitable water values anyway.

Significant cold air advection will take place today and tonight.
High temperatures today will only be in the teens and 20s with
steady or falling temperatures once frontal passage occurs.
Expect wind chill values to drop to 15 below zero late tonight
with even colder values Tuesday night.

Based on the above...will issue a Winter Weather Advisory from this
afternoon through Tuesday to cover both the expected snow and cold
wind chills. Will continue a Wind Chill Advisory Tuesday night/early
Wednesday as values approach 25 below zero.

Conditions will improve Wednesday as 500 mb ridge builds over the
High Plains in response to the prognosticated 500 mb closed low moving
over the Desert Southwest. So...will go with a dry and not as cold
forecast for that period.

Long term...(thursday through sunday)
issued at 239 am MST Monday Dec 29 2014

Closed low over SW US ejects across the Southern Plains through
this weekend. Ahead of this feature shortwave ridging will help
moderate temperatures aloft. As upper low shifts east northwest flow will build
into the northern plains keeping lower heights in place and
reinforcing shots of cooler air over our County Warning Area. Below normal
highs/lows will continue with highs below freezing and overnight
lows in the single digits/teens.

Regarding precipitation chances...most periods will remain dry with only
mention of possible measurable precipitation on Friday/Friday night. There
are differences in evolution of the upper low as it tracks
east...however GFS/European model (ecmwf) and ensembles showing similar overall
pattern. This appears to have minimal impact on sensible weather
over our County Warning Area as this track will generally favor dry conditions for
our County Warning Area. There could be a brief period of very light snow in our far
east/southeast...or freezing drizzle as low level moisture rotates
north through the south/southeast flow along occlusion. Pretty low
confidence in any measurable precipitation in our County Warning Area at all based on this
southern track. I kept slight chance mention in our east/southeast
Friday/Friday night based on consensus/mean...but could see removing
this if trends continue the way they are. There could also be a
quick shot of flurries on the back side of the upper level low in
our west as the weaker secondary 300 mb jet rotates through the
central rockies Friday night...but models generally showing
limited moisture return/lack of middle level moisture. I decided
against adding mention of this during this forecast cycle.


Aviation...(for the 12z tafs through 12z Tuesday morning)
issued at 427 am MST Monday Dec 29 2014

Satellite imagery shows fog dissipating at kgld. Will keep
mention of IFR conditions through 14z...and lift ceilings to VFR
levels. Expect IFR conditions again after 18z as snow develops
behind an Arctic cold front. MVFR ceilings currently are spreading
across western Nebraska...and these conditions will move over kmck
after 14z. Like kgld...expect IFR conditions to develop there in
snow behind the front.


Gld watches/warnings/advisories...
Kansas...Winter Weather Advisory from 11 am MST /noon CST/ this morning
to 5 PM MST /6 PM CST/ Tuesday for ksz001>004-013>016-

Wind Chill Advisory from 5 PM MST /6 PM CST/ Tuesday to 8 am MST
/9 am CST/ Wednesday for ksz001>004-013>016-027>029-041-042.

Colorado...Winter Weather Advisory from 11 am this morning to 5 PM MST
Tuesday for coz090>092.

Wind Chill Advisory from 5 PM Tuesday to 8 am MST Wednesday for

NE...Winter Weather Advisory from 11 am MST /noon CST/ this morning
to 5 PM MST /6 PM CST/ Tuesday for nez079>081.

Wind Chill Advisory from 5 PM MST /6 PM CST/ Tuesday to 8 am MST
/9 am CST/ Wednesday for nez079>081.



Short term...Mentzer
long term...Dr

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