Area Forecast Discussion
Issued by NWS Grand Junction, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS65 KGJT 152318

Area Forecast Discussion
National Weather Service GRAND JUNCTION CO
418 PM MST Fri Dec 15 2017

.SHORT TERM...(Tonight through Saturday night)
Issued at 340 PM MST Fri Dec 15 2017

The next Pacific trough will continue to move into the northern
Great Basin this evening and into Saturday, allowing southwesterly
flow to increase over our forecast area. Mid and high level clouds
will gradually increase over the next 12 hours ahead of this
system which will keep tonight`s overnight lows several degrees
warmer than last night. Some isolated showers will develop over
the higher terrain of northeastern Utah and northwestern Colorado during
the day on Saturday which will provide a quick shot of snow before
this system splits and the better moisture and energy is ejected
well to our south by daybreak Sunday.

.LONG TERM...(Sunday through Friday)
Issued at 340 PM MST Fri Dec 15 2017

Some isolated orographic showers will persist over the region on
Sunday as the base of the shortwave trough lifts to the northeast
while the cutoff low brings cooler and unsettled conditions to
Arizona and New Mexico. Drier air will begin to work into the
region on Monday as the upper level flow shifts to the northwest.
A few light snow showers may linger across the Elkhead and Park
Mountains on Monday but otherwise heavier cloud cover will
dissipate and temperatures will moderate through midweek.

The southwesterly wind gradient will once again tighten across the
region Wednesday evening as the next, more substantial trough of
low pressure drops into the Great Basin. Both the Euro and GFS are
carving a closed low out of this system by the time it reaches the
Utah border late Wednesday. Moisture wrapping around the low looks
to produce scattered showers across our forecast area through
Thursday before the models show a similar track to the previous
system in terms of splitting the storm and sending the low down
south again. The reason for this is the highly amplified ridge of
high pressure that dominated the western CONUS in recent weeks is
still present over the Pacific Ocean and the jet stream riding
the top of the ridge is helping usher these systems south. The
good news for us, though, is that if this closed low develops as
predicted, we should have a better chance of receiving the much
needed moisture. The influx of cold air with the arrival of this
system remains impressive and snow levels are expected to drop
down to valley floors so we`ll have to wait and see if we can get
some snow for those areas!


.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 416 PM MST Fri Dec 15 2017

Plenty of clouds can be found to our north and west and they will
slowly infiltrate our area starting tomorrow morning. Clear skies
overnight will slowly become broken to overcast towards 18Z but
will remain at or above 20K feet. VFR remains the constant.




AVIATION...TGR is the U.S. government's official web portal to all federal, state and local government web resources and services.