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Area forecast discussion 
National Weather Service Grand Junction Colorado
329 PM MDT Thursday Jul 28 2016

Short term...(tonight through Friday night)
issued at 325 PM MDT Thu Jul 28 2016

The broad subtropical ridge remains anchored near Las Vegas. Near
record heat has continued today. In northwest flow aloft, moisture has
eroded for the north and central zones. Marginal moisture lingers
in the south with dewpoints in the 40s and precipitable water
values around 0.5 inch. Afternoon storms formed over the Abajo and
San Juan Mountains and then slowly moved over valleys to the
south. A few storms may continue until midnight across eastern
Utah and far SW Colorado producing gusty outflow winds but little
to no rain.

Friday increasing mid-level moisture continues to rotate around
the high mainly into eastern Utah. Late-day lightning and gusty
winds appear the main threat for eastern Utah. SW Colorado
marginal moisture erodes for only isolated storms there. Very warm
conditions continue.

Long term...(friday night through thursday)
issued at 325 PM MDT Thu Jul 28 2016

Moisture continues to advect into south Friday night that may keep
a few overnight storms there.

The pattern change remains the same in the latest models adding
forecast confidence. Timing may be a bit faster than previous
runs. Over the weekend and into next week, upper lows track
across the northern tier of states. This flattens the subtropical
ridge and nudges it east. This allows marginal monsoonal moisture
to push back north of The Four Corners beginning Saturday evening.
The GFS has precipitable water values approaching one inch in the
southern valleys through Monday, decreasing to around 0.75 inch in
the north.

Beginning Tuesday, strengthening SW flow will bring deeper
moisture into the region. The south could see precipitable water
climb to around 1.25 inches which would raise flash flood concern.

Temperatures drop through the new week returning to near normal by
Wednesday. Rising dewpoints will make for muggy conditions.

&&

Aviation...(for the 00z tafs through 00z Friday evening)
issued at 325 PM MDT Thu Jul 28 2016

VFR conditions will continue through Friday night with terrain
driven winds. Exceptions are ktex kdro which could have brief
impacts, mainly from erratic outflow winds, from showers and
thunderstorms over the higher terrain until 06z. Friday afternoon,
isolated thunderstorms will be limited to the Utah higher terrain
possibly impacting kvel by late afternoon.



&&

Gjt watches/warnings/advisories...
Colorado...none.
Utah...none.
&&

$$

Short term...Joe
long term...Joe
aviation...Joe

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