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Area forecast discussion 
National Weather Service Grand Junction Colorado
545 PM MDT Thursday Sep 3 2015

Short term...(tonight through Friday night)
issued at 300 PM MDT Thursday Sep 3 2015

A disturbance has lifted NE through the day...into northwest Colorado
this afternoon. Storms will favor the Yampa River basin and
Elkhead/park/Gore/Flat Top ranges this late afternoon. Elsewhere
good moisture and marginal instability will keep mainly higher
terrain storms going until sunset. There will be a convective
break through much of the night tonight. After midnight the next
disturbance will push into The Four Corners. Chances of storms
will be on the increase across the south in the early morning
hours. Precipitable water values reach a maximum towards morning
with this surge...1.2 inches across southeast Utah.

The above mentioned disturbance will track north-northeast on
Friday with an uptick in showers and thunderstorms spreading
northward through the day. This activity will be enhanced by the
diurnal effects during the afternoon...and as moisture levels
increase through the day. Also a jet streak overhead will provide
some upper level support...albeit on the weak side. In any case
Friday promises to be the most productive and wettest day for this
latest sub-tropical moisture surge. Activity will diminish from
the west during the evening. However...expect some nocturnal
storms to persist overnight.

Due to the increased clouds/precipitation...daytime highs will
run a little below normal...with nighttime lows a little above

Long term...(saturday through thursday)
issued at 300 PM MDT Thursday Sep 3 2015

A slow drying trend will develop by early Sat...with a downturn in
showers and thunderstorms expected. Models show precipitable
water values (pw) will range from 0.75 to 1+ inch Sat
morning...and then will slowly decrease late in the day. There
will still be pretty good coverage of storms during the afternoon
with the aid of daytime heating. But both coverage and intensity
will see a downturn as compared to Friday. Temperatures will remain
below normal.

The drying trend will strengthen Sat night and sun. As a
result...most convective activity will end by midnight Sat night.
By Sun afternoon models indicate that precipitable water will have fallen to 0.25
inch across much of the forecast area with as much as 0.5 inch
lingering over The Four Corners. While skies will be sunny to
mostly sunny...temperatures will remain on the cool side...and
showers and thunderstorms will have a hard time developing even in
the afternoon.

Then a little moisture will creep across the southern border
early in the work week...but most of the area will remain quite
dry. This modest southerly moisture will bring a chance of showers
and thunderstorms to the San Juans mountains each afternoon...but
the remainder of the area should remain dry. Temperatures will be
near normal.


Aviation...(for the 00z tafs through 00z Friday evening)
issued at 545 PM MDT Thursday Sep 3 2015

Isolated -shra/-tsra will be dissipating between 00z-02z this
evening. No significant weather is expected overnight. Clouds and
moisture will be on the increase from the south Friday morning.
-Shra/-tsra will be on the increase by Friday afternoon and
expected to be in the vicinty of the taf sites in southwest and
west central Colorado.


Gjt watches/warnings/advisories...


Short term...Joe/eh

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