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Area forecast discussion 
National Weather Service Cheyenne Wyoming
541 am MDT Wednesday Apr 1 2015

Short term...(today and through Friday night)
issued at 330 am MDT Wednesday Apr 1 2015

After a prolonged stretch of mild weather...changes will begin to
occur today. A cold front will quickly move across the forecast
area in association with a shortwave moving east through the
northern rockies. Of course cooler temperatures will follow with
high temperatures in the 50s and 60s today. A few rain showers are
possible today but a vast majority of the area will not see
measurable rain. The best chances will be near the Interstate 80
corridor this afternoon...but the models have trended drier and
farther south with precipitation for today.

A second cold front will move across the area Thursday while at
the same time a southern stream shortwave will move from Utah
into southern Colorado. It continues to look like southern
portions of the forecast area will see precipitation develop after
sunrise Thursday as upslope low level flow combines with difluent
flow aloft ahead of the shortwave. The most persistent and
strongest upper level forcing continues to be depicted south of
the forecast area into Colorado by both the GFS and European model (ecmwf). At this
time not too excited about the potential for snow accumulations
Thursday into Thursday night. Based on current timing...most
precipitation will fall late Thursday morning through Thursday
afternoon. Where it is cold enough for snow...accumulations will
be significantly reduced as surface temperatures will generally
remain above freezing and the relatively high sun angle will
continue to warm the surface causing more melting. Therefore
impacts on travel will be minimal through Thursday afternoon. As
the sun sets Thursday evening and temperatures dip below
freezing...light snow accumulations will remain possible with some
roads in the Cheyenne to Laramie areas could become

Precipitation will taper off Thursday night into Friday with high
pressure pushing into the area. Temperatures will fall into the
teens and 20s Thursday night. Dry conditions are expected across
the area by Friday afternoon along with moderating temperatures.
Clear skies...light winds and cooler temperatures will prevail
Saturday night as a upper ridge shifts into The Rockies.

Long term...(saturday through tuesday)
issued at 230 am MDT Wednesday Apr 1 2015

Warm and dry conditions are likely through the weekend with models
in good agreement with broad upper-level ridging. Deep mixing along
with strong flow aloft will promote gusty winds each afternoon.
Best low level gradients are prognosticated to be along and west of the
Laramie range through Sunday. GFS BUFKIT soundings show 50 knots
winds at 500 mb over rwl at 21z sun with nearly dry adiabatic lapse
rates extending above and beyond that level. The GFS would be
favorable for a warning criteria event out west with excellent
subsidence beneath coupled upper level jet streaks. The European model (ecmwf)
shows considerably weaker low level not comfortable going too
far above guidance just yet. Fire weather will be an issue this
weekend with a pattern like this. GFS/European model (ecmwf) quickly diverge into
early next week with a deep upper trough digging into the western
Continental U.S.. the GFS pushes an energetic lead shortwave east into the
central rockies on Monday...while the European model (ecmwf) keeps most of the middle
level energy to the west over northern California. Did not make many
changes to the inherited forecast with this uncertainty. The
overall trend through early next week should be toward cooler and
wetter as the aforementioned trough advances eastward.


Aviation...(for the 12z tafs through 12z Thursday morning)
issued at 535 am MDT Wednesday Apr 1 2015

VFR. Gusty winds will develop across much of southeast Wyoming and the
western NE Panhandle this afternoon. Winds should diminish after
sunset. Look for lowering ceilings overnight with cloud bases between
5-10k feet above ground level.


Fire weather...
issued at 230 am MDT Wednesday Apr 1 2015

No fire weather concerns the next several days with cooler
temperatures in place across the region. Wetting precipitation is
likely near the Interstate 80 corridor Thursday but farther
north chances for precipitation are minimal...such as across east
central Wyoming and the northern Nebraska Panhandle.


Cys watches/warnings/advisories...


Short term...small
long term...clh
fire weather...small

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