Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 192233

Area Forecast Discussion
National Weather Service GRAND JUNCTION CO
333 PM MST Fri Jan 19 2018

.SHORT TERM...(Tonight through Saturday night)
Issued at 333 PM MST Fri Jan 19 2018

Southwest flow bringing strong WAA into the region will keep
temperatures mild this evening, and pump a swath of above normal
moisture for this time of year in from Baja CA. A -30C H5 open
wave is expected to push westward into Utah Saturday afternoon,
with showers developing along and ahead of the associated cold
front west to east during the day Saturday across eastern Utah and
western Colorado. Before the front even makes its way past NE
Utah, forecast models continue to indicate the front getting hung
up on the Uinta Mountains early Saturday, shown very vividly on
MSLP height plots. Because of the front stalling, snow amounts in
excess of a foot are likely across highway 191 and UT state route
44 from Manilla to Flaming Gorge and through the Uinta mountains.
Anticipating a sharp gradient in snow amounts between the eastern
Uinta mountains and the eastern Uinta basin in Vernal with
shadowing on the leeward side, but a couple of inches of snow will
be possible in the eastern Uinta basin. Weaker energy should
eject at mid and upper levels eastward late Saturday afternoon and
push the front into western Colorado. As the front pushes eastward
Saturday night, much of western Colorado will see rain and/or
snow with cooler air lowering snow levels throughout the night.

Areas normally favored in northwesterly flow (Routt Co south to
Pitkin Co and northern Gunnison Co) will not likely see any snow
until the mid level front reaches them Saturday night.

.LONG TERM...(Sunday through Friday)
Issued at 333 PM MST Fri Jan 19 2018

Closed Colorado low will strengthen on the Front Range Sunday
morning, with upper level support following. Wrap around moisture
with primo dendritic crystal growth on Sunday morning may bring
good snowfall rates across the central CO mountains for the first
part of the day before orographic snowfall ends later in the day
with the ejection of the closed low eastward across Kansas.

A stable and cool airmass will develop on Monday behind the front,
but forecast models are trending toward zonal flow and possibly a
weak disturbance Monday into Tuesday bringing light snow to the
northcentral Colorado mountains.

Southwest flow increases on Thursday ahead of the next weather
maker rolling in from the west on Friday. Additional snow will be
possibly late next week into the early weekend.


.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1037 AM MST Fri Jan 19 2018

Mid and high level cloudiness will continue to stream overhead on
strong southwesterly flow ahead of the next system. Mountain wave
turbulence could be an issue overhead while down at the surface
lighter winds are not expected to be an issue most areas.
Tailwinds leading to into KASE this morning are forecast to
become more southerly through the day. CIGS will lower on Saturday
morning but the only impact at this time will be at KVEL where the
snow will developing after sunrise and MVFR conditions are
expected to develop.


CO...Winter Weather Advisory from 2 PM Saturday to 2 PM MST Sunday
     for COZ003-009-017>019.

     Winter Storm Watch from Saturday evening through Sunday evening
     for COZ004-010-012-013.

     Winter Weather Advisory from 6 PM Saturday to 10 AM MST Sunday
     for COZ001.

UT...Winter Weather Advisory from 10 AM Saturday to 10 AM MST Sunday
     for UTZ025-028.

     Winter Storm Warning from midnight tonight to 6 AM MST Sunday
     for UTZ023.



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