Area Forecast Discussion
Issued by NWS Grand Junction, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 122331

Area Forecast Discussion
National Weather Service GRAND JUNCTION CO
431 PM MST Sun Nov 12 2017

.SHORT TERM...(Tonight through Monday night)
Issued at 222 PM MST Sun Nov 12 2017

As expected, west-southwesterly flow and the influence of a
subtropical jet overhead has resulted in a mild afternoon with
mostly to partly cloudy skies across the region. The increased
cloud cover will allow overnight lows tonight to jump several
degrees from last night as well as sit some 5 to 10 degrees above
normal. Monday`s weather will be very similar to today`s, though
clouds will gradually dissipate as the subtropical jet shifts out
of our region.

As far as the overall synoptic pattern goes heading into the new
work week, a weak Pacific shortwave trough will be ejected into
the northwestern CONUS while a more substantial upper level trough
drops in from the Gulf of Alaska. The progression of both these
features will flatten the area of high pressure situated to our
south and allow for southwesterly flow to persist over our region.

.LONG TERM...(Tuesday through Sunday)
Issued at 222 PM MST Sun Nov 12 2017

A weak ripple in the southwesterly flow will just barely clip our
northern CWA Tuesday afternoon and evening and will generally
bring just some passing mid and high level clouds, though the
Eastern Uinta and Elkhead mountains may see some light flurries.
The stronger Pacific trough mentioned in the short term discussion
will be moving inland on Wednesday and into Thursday morning with
the southwesterly gradient tightening over eastern Utah and
western Colorado as an upper level jet moves into the region. The
12Z model runs are showing an even stronger jet with 250mb speeds
ranging from 120 to 140kts so Thursday afternoon in particular
should be a breezy day. Scattered to numerous valley rain and
mountain snow showers will develop ahead of and along a cold
front associated with the trough beginning Thursday afternoon and
continuing through Friday morning. The latest Euro is still
lagging behind the GFS in regards to timing but both solutions
show a cold and unsettled end to the work week. As was hinted at
yesterday, a blend of model solutions would drop snow levels from
between 8500 to 9500 feet Thursday afternoon down to the high
elevation valleys further north and to between 7000 and 8500 feet
down south by daybreak Friday. The passage of the cold front
during the day on Friday will cool temperatures back down to near
or slightly below climatological norms. These seasonal conditions
will be short-lived, however, as dry northwesterly flow re-
establishes itself over the region for Saturday and Sunday.


.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 419 PM MST Sun Nov 12 2017

Dense high cloud cover will remain in place overnight with some
thinning expected after 12Z, with clouds diminishing by midday
Monday. Winds will remain light and terrain driven with VFR
conditions in place at all sites.




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