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Area forecast discussion 
National Weather Service Grand Junction Colorado
1202 am MDT Thursday Oct 2 2014

Update...
issued at 1200 am MDT Thursday Oct 2 2014

Small areas of showers are still moving through western Colorado
at midnight. But no further significant snow accumulations are
expected in the high country. The Winter Weather Advisory was
allowed to expire.

Update issued at 933 PM MDT Wednesday Oct 1 2014

The trough and cold front that brought today's weather will
continue moving east tonight...with clearing skies behind it.
Southwest Colorado...southeast and east-central Utah were mostly
clear...with the sky clearing over northeast Utah. Late this
evening scattered showers and a few thunderstorms still affected
the Colorado northern and central mountains and the high valleys
of central Colorado. From Grand Junction east the valleys will
continue to see occasional light to moderate rain with the
mountains receiving occasional snow above about 8000 feet. After
midnight the upper trough should move out of the forecast area
then rapid cooling under nearly clear skies should produce areas
of fog in most low lying areas until mid-morning.

&&

Short term...(tonight through Thursday night)
issued at 256 PM MDT Wednesday Oct 1 2014

Long wave trough axis will be sliding east of the forecast area
this evening with cold northwest flow settling in behind later tonight.
In the meantime...convection associated with second wave of
energy passing through the long wave trough now driving east
across the forecast area. Showers becoming more scattered in
nature with embedded thunderstorms as cold core of upper level
system passes overhead. Concerns overnight will continue to be
align with mountain snowfall and freezing temperatures down into the
valleys overnight. Webcams...spotters and high elevation snotels
indicating anywhere from 1 to 6 inches thus far above the 9k level
with another 1 to 2 inches expected with passing wave this
evening. West-northwest component to the flow has not been favorable for the
eastern Uinta Mountains and went ahead and dropped them from the
Winter Weather Advisory. The higher mountains in western Colorado
remain favored orographically and will continue the highlights in
those areas until midnight tonight.

After midnight...expect showers to end quickly with clearing skies
by sunrise. This sets the stage for the coldest morning so far
this season across most of the forecast area. Have upgraded the
freeze watch to a freeze warning for all northern Colorado valleys
and the higher Interstate 70 valleys east of Grand Junction and in
the Gunnison area. In addition...colder air settles into the
southern valleys by morning with readings dropping to around
freezing from Cortez to pagosa. Patchy valley fog also possible
overnight...especially near rivers and small streams.

This storm system moves onto the plains by tomorrow morning...phases
with northern stream energy...and helps carve out a deep central
noam trough through week/S end. Progressive northwest flow will be
over our County Warning Area during this time...with heights rising and middle level
warm air advection increasing as we transition from the back of the trough to the
leading edge of the negatively tilted western ridge. New snow
cover/precipitation and cool nights will leave a cool boundary
layer in place the next few mornings. Inversions aloft look to
prevent deep mixing and the trend of cooler than normal
temperatures will hold Thursday. Another cold night will on tap as
clear skies and dry air continues to filter in tomorrow night and
most areas that freeze tonight will see the same tomorrow. A wave
moving through the northwest flow will move just northeast of our
County Warning Area and at the most looks to brush the northern mountains with
some middle level clouds.

Long term...(friday through wednesday)
issued at 256 PM MDT Wednesday Oct 1 2014

The long term period weather pattern will be dominated by and
anomalously deep trough over the eastern half of the Continental U.S. And
strong ridge in the west. The northwest flow persists over our County Warning Area
though Monday then should be veering more westerly by late in the
forecast as the eastern trough axis rotates northeastward. Really
nothing profound to prognosticate during this period as dry and
seasonal conditions should bring a nice change to the recent
stormy pattern to start out the fall season.

&&

Aviation...(for the 06z tafs through 06z Thursday night)
issued at 933 PM MDT Wednesday Oct 1 2014

Rain and snow showers will continue until about 08z at kase and
kege with MVFR and brief IFR ceilings and visibilities expected. The northern
and central mts of Colorado will remain mostly obscured until
about 08z as well. VFR conditions should prevail elsewhere...but
the clearing skies will also cause fog to form in low lying areas
which should impact flight conditions at kege...kgjt...kase...kcag
and khdn. After about 16z Thursday the fog should lift and VFR
conditions will prevail.



&&

Gjt watches/warnings/advisories...
Colorado...freeze warning until 9 am MDT this morning for coz001-002-005-
007-008-014-021>023.

Utah...freeze warning until 9 am MDT this morning for utz024.

&&

$$

Update...Joe/cc
short term...jdc
long term...15
aviation...cirrocumulus

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