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Area forecast discussion 
National Weather Service Cheyenne Wyoming
1113 PM MDT Thursday Jul 31 2014

issued at 912 PM MDT Thursday Jul 31 2014

Light winds...mild temperatures and mostly clear skies for
tonight under the influence of an upper level ridge. Forecast
right on track so no changes to the forecast.


Short term...(this evening through Saturday night)
issued at 335 PM MDT Thursday Jul 31 2014

Current visible satellite loop shows mainly clear skies across the
area with light north to northwest flow. Drier air has pushed into
the area as a result with most of the moisture from earlier this
week down across southern Colorado and New Mexico. There is still
a slight chance at a thunder shower or two across the
mountains...but have not seen too much activity north of Steamboat
Colorado this afternoon so the probability for these thunder
showers appear rather low at this time. Another cool night
expected tonight with lows in the middle 40s to middle 50s. May be a few
readings between 35 to 40 degrees across the Laramie valley by
early Friday morning.

Very little will change for Friday and Saturday with northwest
flow aloft continuing over the area. Surface winds will shift into
the southeast with somewhat better moisture profiles on model
soundings. With just enough instability expected...may see some
light thunder showers across southeast Wyoming and northern
Nebraska...but they should be pretty isolated outside of the
mountains. Not confident about thunderstorm activity on Saturday
outside of the mountains with a bit less moisture compared to
Friday and increased warming/subsidence aloft. Kept high
temperatures near or slightly below normal over most locations and
a few degrees below MOS...mainly because of the southerly surface
winds. Guidance tends to have a noticeable warm bias in these
cases...especially across the more exposed ridges.

Long term...(friday night through thursday)
issued at 335 PM MDT Thursday Jul 31 2014

The broad upper ridge will remain over The Rockies on Sunday with
a shortwave beginning to slowly move north across the Desert
Southwest and into the Great Basin. Expect very warm temperatures for the
County Warning Area on Sunday in advance of this wave...with increasing chances
for afternoon thunderstorms in the mountains. The initial push of
deeper monsoonal moisture associated with the approaching
shortwave will impact the County Warning Area on Monday...and the GFS shows an
initial piece of energy somewhat stronger than the European model (ecmwf) or Gem
models moving across the region through Monday night. Will
maintain chance to slight chance probability of precipitation from west to east across the
County Warning Area for Monday and Monday night for this scenario. In general...the
European model (ecmwf) maintains a more coherent shortwave trough moving across the
area through Wednesday while the GFS shears it out into more a
stream of midlevel energy through this time. Regardless the
solution...plentiful subtropical moisture will remain over the
County Warning Area through this time with precipitable waters prognosticated to range from three-
quarters an inch to an inch and a half from west to east. As a
result...looking at a good chance for scattered showers and
thunderstorms tues-Wed. With fairly warm temperatures prognosticated as
well...lifted indice's will average around minus 2 or less...which suggests
that convection could become quite vigorous at times. In
addition...relatively weak winds will occur at jet
looking at the potential for very heavy rain out of this activity.
Much drier air will filter in from the north on Thursday and will
bring overall drier conditions to the County Warning Area. Temperatures will remain near
to slightly below normal tues-thurs.


Aviation...(for the 06z tafs through 06z Friday evening)
issued at 1113 PM MDT Thursday Jul 31 2014

VFR expected over all terminals through the period. Isolated
showers and thunderstorms possible over the southeast Wyoming mountains
near the Colorado border Friday afternoon. Coverage will be very
limited if any occur.


Fire weather...
issued at 220 PM MDT Thursday Jul 31 2014

No fire weather concerns anticipated through the middle of next
week with light winds and temperatures remaining near or slightly
below average. A slight chance of thunderstorms will continue over
the mountains through this weekend. Thunderstorms will become more
widespread by Tuesday of next week...bringing another good chance
for widespread wetting rainfall.


Cys watches/warnings/advisories...


short term...tjt
long term...rjm
fire weather...tjt

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