Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 181150

Area Forecast Discussion
National Weather Service GRAND JUNCTION CO
550 AM MDT Sun Mar 18 2018

.SHORT TERM...(Today through Monday)
Issued at 322 AM MDT Sun Mar 18 2018

The latest Pacific storm system to impact the area began to
generate snowfall over the eastern Uinta Mountains last evening.
Later, in the early morning hours, overrunning snowfall began
over the eastern Uinta Basin and a portion of northwest Colorado
as the cold front associated with this system moved across those

Models indicated the front will be stalled through the latter part
of the morning as the jet on the west flank of the trough digs
southward during the early part of the day before swinging
eastward. Dynamic forcing and steepening lapse rates will cause
precipitation to increase in coverage and spread eastward in
step with the movement of the southern end of the upper-level
trough. Widespread precipitation will continue over the area this
afternoon as the trough axis passes over the region and pushes
east of the divide. Subsidence in the wake of the trough will
bring an end to showers over eastern Utah and the western border
areas of Colorado this evening. However, lingering moisture,
instability and orographic lift will continue to generate snowfall
over the western Colorado mountains during the remainder of the
night and possibly into Monday morning. A few scattered showers
with little accumulation are possible over the Elkhead and Park
Mountains Monday afternoon while dry and partly to mostly sunny
conditions prevail elsewhere.

Adjusted the Winter Weather Advisories with this package based on
latest models. Specifically, ended highlights over the eastern
Uinta Basin at noon and the eastern Utah mountains at 6 PM. In
addition, dropped the advisories for northwest Colorado as that
region should linger in the warm sector of the storm longer than
earlier indicated. Therefore, believe milder temperatures will
limit accumulations to less than 3 inches. In contrast, held onto
the Winter Weather Advisory for the eastern Uinta Basin as steady
overrunning snowfall will hold temperatures down, allowing snow to
accumulate with less melting.

.LONG TERM...(Monday night through Saturday)
Issued at 322 AM MDT Sun Mar 18 2018

High pressure builds in across the western US for the first half of
the new work week bringing near or slightly above normal
temperatures to the region. The next trough developing over the west
coast by Wednesday will be the result of a merger of several low
pressure circulations across the eastern Pacific. Southwest flow
increases again on Wednesday, with active weather possibly returning
for the end of the work week and into the weekend. Forecast models
differ on features out past Wednesday, so confidence is low on day 5
to 7 features at this time.


.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 550 AM MDT Sun Mar 18 2018

TAF sites will experience rain and snow over the next 12 hours.
TAF sites in eastern Utah will see an end to showers by midday,
but until then snow will bring MVFR CIGS and IFR VSBY to KVEL.
Brief MVFR conditions are possible at KCNY as rain showers are
more likely. The higher elevation TAF sites in western Colorado
will experience a rain/snow mix followed by all snow late this
afternoon and early this evening. This will result in MVFR CIGS
and periods of IFR VSBY. In addition, a number of sites will have
CIGS below ILS breakpoints. Conditions improve overnight with
showers ending. However, CIGS may linger below ILS breakpoints at



CO...Winter Weather Advisory from 9 AM this morning to 6 AM MDT
     Monday for COZ009-012-018-019.

     Winter Weather Advisory until midnight MDT tonight for COZ003-

     Winter Weather Advisory from noon today to noon MDT Monday for

UT...Winter Weather Advisory until 6 PM MDT this evening for UTZ023-

     Winter Weather Advisory until noon MDT today for UTZ024.

     Winter Weather Advisory until 6 PM MDT this evening for UTZ028.



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