Area Forecast Discussion
Issued by NWS Grand Junction, CO

Current Version | Previous Version | Text Only | 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 202157

Area Forecast Discussion
National Weather Service GRAND JUNCTION CO
257 PM MST Mon Nov 20 2017

.SHORT TERM...(Tonight through Tuesday night)
Issued at 253 PM MST Mon Nov 20 2017

Fast moving Pacific wave will work across the northern and central
zones tonight as it slides down the front side of strengthening
Great Basin ridge. Moisture will slowly deepen across the northern
and central zones with more mid-level clouds showing up on
upstream observations. Light radar returns also picking up across
southeast Idaho and northwest Wyoming.

This activity will work southeast as leading edge of strong upper
level jet arrives drives over our northern zones this evening and
into the central mountains overnight. With improving jet
dynamics, moisture and favorable orographics, expect to see a
quick round of snow favoring the Park and Gore ranges between
midnight tonight and midday Tuesday. Amounts will be held in check
by the speed of this system and the fact our lower levels remain
quite dry. So top-down saturation will need to occur and model
soundings suggest this will somewhat slow. But it will happen and
we will see a quick 3 to 6 inches of new snow over our northern
mountains with lighter amounts trailing back over the Flat Tops
and into the Central Mountains from Vail to Aspen. Of course,
highest peaks may do a tad better, but overall this storm is
coming in under advisory criteria. Valleys locales from Craig
southeast toward Eagle and Avon should see a few light showers as
well, but no significant snowfall is anticipated in these areas.
The remainder of the forecast area will remain dry with moderated
overnight lows tonight thanks to the abundant mid and high clouds
moving through. This system exits the region Tuesday afternoon and
evening. Temps will remain at or slightly below seasonal normals
Tuesday with clouds helping to hold mins up again Tuesday night.

.LONG TERM...(Wednesday through Monday)
Issued at 253 PM MST Mon Nov 20 2017

Dry and mild conditions will be in place through much of the
Holiday weekend as a strong ridge of high pressure remains parked
across the western U.S. A few weak waves will top the ridge and
drive southeast across our northern mountains, dragging an
increase in cloud cover and possibly a few light showers Wednesday
afternoon and again Friday afternoon. Otherwise, we are looking at
several more days of dry with temperatures running a solid 5 to 10
degrees above normal. Beyond this time period, models still
hinting at a system coming through the region next Tuesday.
However, there remains large spreads between the EC and GFS with
the strength and placement of this system. Longer range outlooks,
into week two, still leaning toward a wetter pattern with
temperatures backing off a bit, but still favoring a warmer


.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1101 AM MST Mon Nov 20 2017

Some mid and high clouds will move across the area, increasing in
coverage this evening into Tuesday morning as a disturbance moves
through. The northern and central divide mountains may see some
obscuration in snow showers with ceilings dropping to near MVFR
conditions but light accumulations are anticipated. Winds will be
light and terrain driven at most TAF sites with some breezy
conditions possible at the higher elevation TAF sites. Mountain
turbulence will be seen among the higher peaks and above. Aside
from the northern and central mountain sites, VFR conditions will




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