Area Forecast Discussion
Issued by NWS Grand Junction, CO
FXUS65 KGJT 272347
Area Forecast Discussion
National Weather Service Grand Junction CO
447 PM MST Mon Feb 27 2017
.SHORT TERM...(Tonight through Tuesday night)
Issued at 345 PM MST Mon Feb 27 2017
Gusty southwesterly winds are being reported across the forecast
area this afternoon as a storm system continues to push east
towards the forecast area. The current satellite water vapor image
is showing the associated trough of low pressure sliding through
the Great Basin placing Utah and Colorado in moist southwesterly
flow. The satellite and GPS derived total precipitable water image
is showing between 0.50 and 0.60 inches of precipitable water or
about a 116 percent of normal pushing into the Four Corners.
Over the next 18 to 24 hours the 1800Z GFS is showing a 150 kt
jetstream passing over head while at the surface a cold front is
expected to push southwest overnight. These conditions support
gusty southwesterly winds which may be strong at times,
especially over the higher terrain through this evening. Ahead of
the front modest isentropic ascent is in place and will lift the
afore mentioned moisture resulting in light to moderate rain in
the valleys with mountain snows. The rain in the valleys will
transition over to snow later this evening.
The trajectory of the moisture and lift will provide southern
portions of the CWA enhanced precipitation. Therefore Winter
Weather Advisory and Winter Storm Warnings are in place across
the southern CWA including low elevations. In addition Winter
Weather Advisories and Winter Storm Warnings are in place for
many of our Mountain zones. Some of the areas of heavier snow fall
are expected to be the San Juan Mountains, especially
southwesterly facing slopes. The storm system should be east of
the area by late Tuesday morning bringing an end to the snowfall
by Tuesday evening.
.LONG TERM...(Wednesday through Monday)
Issued at 252 PM MST Mon Feb 27 2017
The 1800Z GFS20 and 1200Z ECMWF have initialized well with the
current synoptic weather pattern and remain in good agreement
through the up coming weekend. Both models quickly build a broad ridge
of high pressure over the the Western CONUS behind the departing
system which is impacting our area Today. This broad ridge of high
pressure will bring dry weather and a modest warming trend for
the second half of the week.
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 447 PM MST Mon Feb 27 2017
Moist and intense storm will be bringing snow...heavy at times to
much of southeast UT and western CO. Winds will also accompany
this snow and lead to areas of blowing snow in the high country
and llws in the valleys. The cold front has passed KVEL and for
the most part VFR conditions will dominate that TAF with low
probability of IFR conditions here. KCNY and KGJT will also likely
stay VFR levels with only temporary downturns as the front passes.
The remaining TAF sites will be under the gun for prolonged
periods IFR/LIFR from this evening through Tuesday morning. The
mountain TAFs of KTEX and KASE and KMTJ may linger in the lower
flight criteria in the cold northwest flow that sets up behind the
CO...Winter Weather Advisory until midnight MST Tuesday night for
Winter Storm Warning until midnight MST Tuesday night for COZ012-
Winter Weather Advisory until 5 PM MST Tuesday for COZ020-021.
Winter Weather Advisory until 11 PM MST Tuesday for COZ014.
Winter Weather Advisory until 5 AM MST Tuesday for COZ004-013.
Winter Storm Warning until 5 PM MST Tuesday for COZ022-023.
UT...Winter Weather Advisory until 9 PM MST this evening for UTZ023.
Winter Weather Advisory until midnight MST Tuesday night for