Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 181026

Area Forecast Discussion
National Weather Service GRAND JUNCTION CO
426 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 06Z TAFS through 06Z Sunday night)
Issued at 1129 PM MDT Sat Mar 17 2018

Cloud cover will increase from west to east, and conditions will
deteriorate overnight as a cold front moves in from the west.
Ceiling heights will lower into MVFR conditions and eventually IFR
conditions at numerous terminals as a cold front passes in the
late morning hours. Expect a period of rain turning to snow at
most terminals, which will temporarily reduce visibilities to 3
miles or less around sunrise in the northwest and through the
early afternoon in the central and southern mountains. Expect
obscurations to terrain and a wind shift from southerly to
westerly as the front passes on Saturday. Conditions will improve
across eastern Utah by 00z Sunday evening, then across most of
western Colorado by 06z Sunday night.



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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