Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 202149 AAC

Area Forecast Discussion...UPDATED
National Weather Service Grand Junction CO
349 PM MDT SAT AUG 20 2016

.SHORT TERM...(This evening through Sunday night)
Issued at 332 PM MDT Sat Aug 20 2016

Trough passage yesterday has caused winds to shift to the west
through northwest today. This has caused precipitable water values
to drop and also kept the atmosphere mostly stable. Granted, a few
showers and thunderstorms have formed over the San Juans mainly
thanks to favorable orographics and moisture content reading a
little higher. Mostly though, a few cumulus clouds will remain
over the higher terrain with temperatures right around normal.
Models want to keep some QPF over the Wolf Creek Pass area
overnight but with loss of heating and no real forcing to speak
of, don`t expect this to pan out so took out any mention of precip
for the overnight hours.

For Sunday, a very broad area of high pressure will remain over
the southern portions of the U.S. while low pressure remains off
the Pacific Coast. These two features will work in tandem to allow
moisture to slowly creep upwards through the day with an increase
in coverage of showers and storms. Even so, areas north of I-70
should remain mostly dry while the San Juans will likely see the
brunt of precipitation. A few showers may persist overnight but
will be very spotty in nature.

.LONG TERM...(Monday through Saturday)
Issued at 332 PM MDT Sat Aug 20 2016

By Monday, a deep area of low pressure will be skirting the
U.S./Canadian border while a weaker trough will be approaching the
area. This trough will keep southwesterly flow in the picture
allowing moisture to increase across the CWA and bring another
round of showers and storms. However, the best coverage for
precipitation looks to be Tuesday as the weak trough moves
overhead. All models are showing a few stronger vorticity maximas
moving overhead, indicating vertical motion, which will allow some
stronger convection.

The rest of the week will remain unsettled as a deeper trough,
extending from southern Canada and reaching the southern
California coast, slowly approaches our region. As it does,
afternoon and evening convection will be common and fairly
widespread though this can change if the trough becomes shallower
or stays further north. MOS guidance suggesting temperatures will
be at or a few degrees below normal for most areas through entire
long term period.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 332 PM MDT Sat Aug 20 2016

VFR conditions remain for the next 24 hours. A few showers and
storms possible over the San Juans but won`t pose any problems for
TAF sites. Chances increase tomorrow from about 18Z onwards for
convection but too far out to include any mention in TAFs.


.GJT Watches/Warnings/Advisories...


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