Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 201702

Area Forecast Discussion
National Weather Service Grand Junction CO
1102 AM MDT WED JUL 20 2016

.SHORT TERM...(Today through Thursday)
Issued at 337 AM MDT Wed Jul 20 2016

The moisture plume remain in place with PWAT over an inch on the
KGJT RAOB at 00z and on ground sensors at KDRO. The radar however
is much cooler tonight with a strong downturn in convection after
midnight with out a strong trigger. This suggests a quieter start
to the day and did lower pops going into the noon hour. Models
still picking out a more distinct wave lifting north out of SW New
Mexico this morning. This feature looks to arrive to the 4 corners
late this afternoon and should provide some focus for storms to
survive into the late evening across our southern CWA. There also
appears to be some channelized vorticity riding the edge of the
moisture plume in southeast Utah that could also focus some storms
across the high plateaus into the northern mountains this
afternoon. Forecast seems to be on track and didn`t make major
changes. All models a bit drier in our far northeast CWA and did
trend QPF and pops downward here. Not much of different story for
Thursday with PWAT still near an inch. Our moisture tap will begin
to be disrupted however by a subtle westward shift in the
subtropical high. Missed the high temperature forecast by nearly
10 degrees yesterday due to cloud cover and early morning
rainfall. A quieter start today and will go with highs near to
slightly above normal the next few days.

.LONG TERM...(Thursday night through Tuesday)
Issued at 337 AM MDT Wed Jul 20 2016

Through Friday, the moist SW flow continues. Both the more moist
NAM and the drier GFS keep precipitable water values over one inch.
No significant disturbances are resolved for now so a broad brush
monsoonal surge forecast continues. The southern and eastern portion
of the forecast area looks to be favored for showers.

By Saturday, the Pacific NW upper Low ejects through the northern
Rockies. This turns the upper flow from SW to a drier west. The
subtropical High also expands across the southern tier of states.
All of this brings a strong drying and warming trend to the
forecast area that continues into at least next Tuesday.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1052 AM MDT Wed Jul 20 2016

Light showers will continue across areas in the vicinity and north
of Interstate 70. Thunderstorm activity is expected to develop
across southeast Utah and southwest Colorado initially and become
widespread across all areas this afternoon and continue this
evening. Some storm activity will continue through the overnight
hours with a disturbance moving through. Some storms will contain
brief moderate to heavy rainfall with temporary MVFR/IFR
conditions possible in the vicinity of airfields with gusty
erratic outflow winds possible as well.


.GJT Watches/Warnings/Advisories...


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