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Area forecast discussion 
National Weather Service Goodland Kansas
431 am MST Sat Dec 20 2014

Short term...(today and tonight)
issued at 238 am MST Sat Dec 20 2014

Areas of fog extend from southwest Kansas through central Kansas
and south central Nebraska early this morning...but has not yet
developed further west over northwest Kansas. Dewpoint depressions
remain minimal across the eastern half of the forecast
area...but with a few high clouds moving across the area...and the
surface trough appearing to have pushed far enough east that the
near surface flow has remained light westerly over the forecast
area...temperatures have remained warmer than initially expected
and the possibility of fog developing has decreased. We may still
develop fog right near sunrise and shortly thereafter if
temperatures tank...but have decided to go ahead and remove fog
this morning as it appears it will remain to the east.

Westerly flow will bring a few weak disturbances east of The
Rockies and across the Central High plains through the weekend.
The pattern amplifies over the western United States as the
eastern Pacific high moves over the West Coast by late Monday. The
upper flow over the Central High plains turns northwesterly on
Sunday as a result of the amplifying pattern with a low pressure
center deepening and moving into the northern plains on Monday.
The European model (ecmwf) and GFS are initially more progressive in moving the
upper low into the northern plains early Monday...but all seem to
fall more in line by Monday night swinging the initial vorticity
maxima through the base of the deepening trough east of The
Rockies and starting to lift it towards the Great Lakes region
while the secondary vorticity maxima dives south into the southern
rockies and continues to deepen trough over the plains states and
further amplify the pattern through Monday night and into Tuesday

A prefrontal trough deepens along the eastern Colorado border
through the day on Sunday with west to southwest surface winds
ahead of the cold front that is expected to move through the
region Sunday night. A secondary cold surge moves through Monday
morning with breezy conditions to follow on Monday and Monday
night. Currently expect light rain/snow to move through the
forecast area Sunday night with the cold front. Should see all
snow by early Monday morning with a transition back to rain as
temperatures warm again on Monday with precipitation expected to
remain in the western sections as the secondary short wave trough
moves along The Rockies and into the southern High Plains by early
Tuesday morning.

Long term...(tuesday through friday)
issued at 228 am MST Sat Dec 20 2014

The long term period will start under the influence of a high
amplitude trough over the Central Plains with a building ridge to
the west along the Colorado Front Range. Although model forecasts
have slight differences in position of the trough...general
agreement is that 500 mb trough axis will be through the area and
surface high pressure will provide dry weather Tuesday and

There is still uncertainty with regards to the potential weather
system that will approach the region for the Christmas day time
frame. An upper level shortwave trough will slide across the
Pacific northwest and bring moisture across The Rockies and into the
Central Plains. Timing generally appears like Thursday evening will
be the arrival time of a surface low pressure system and associated
cold front...however upper level progression is still uncertain.
The European model (ecmwf) depicts a deeper wave than compared to the GFS and
Canadian forecasts. Decided to align the forecast more with what
the GFS is depicting due to agreement with the Canadian well as mex guidance having a better trend for the
weather on Thursday in previous cycles compared to the ece guidance.
Precipitation type with this system will be rain/snow mixes turning
to snow once the front passes with cold air advecting at the

Although the European model (ecmwf) appears to be the outlier at this
predicts a fairly strong pressure gradient that develops across the
High Plains Thursday afternoon through the evening. This could
bring potentially strong wind gusts and blowing snow...however until
there is further agreement in other models...there should be a
relatively mild frontal passage.

Once the shortwave trough aloft passes through the upper
level ridge will build in from the west to provide dry weather
conditions Friday with colder conditions. Friday highs will reach
the middle to upper 30s.


Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 358 am MST Sat Dec 20 2014

A surface trough retrogrades up along the Front Range today and
moves eastward to a position near the eastern Colorado border this
evening. Conditions at mck and gld will remain VFR through the
taf period. A few high clouds and light westerly wind will prevail
through Sunday. Scattered-broken middle level clouds area expected to move in
by 03z at both locations with winds turning southwest as th
surface trough moves further east.


Gld watches/warnings/advisories...


Short term...Lockhart

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