Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 221045

Area Forecast Discussion
National Weather Service GRAND JUNCTION CO
345 AM MST Mon Jan 22 2018

.SHORT TERM...(Today through Tuesday)
Issued at 345 AM MST Mon Jan 22 2018

Satellite imagery showing some low clouds hanging around some of
our higher elevations this morning with a few snow showers thrown
in for good measure. Not expecting anything appreciable, however.
A few spots also seeing some patchy fog including Meeker and
Pagosa Springs but visibilities have been jumping from 1 mile up
to 7 miles then back down to 3 miles. With plenty of residual
moisture in the lower atmosphere thanks to the precip yesterday,
this patchy fog will likely continue for the overnight periods
for the next days.

As far as weather in the short term, more clouds up north than
south as a weak disturbance drops down from the northwest. Latest
model guidance, including the NAMNEST, HRRR, RAP13, NAM12 and GFS,
show minimal snowfall today for the northern mountains with an
uptick expected towards evening as favorable orographics and the
weak shortwave cause enough uplift for some snowfall. Expecting a
few inches...2 to 4 generally...from this disturbance though a few
favored spots may see a bit more than that. The rest of the
forecast area will see variable cloudiness with cool temperatures
remaining in the forecast under surface inversions.

Snow will end by noon Tuesday giving way to sunny skies and
warming temperatures as upper level winds become more
westerly as opposed to northerly for the entire CWA.

.LONG TERM...(Tuesday night through Sunday)
Issued at 345 AM MST Mon Jan 22 2018

Heights will continue to rebound over eastern Utah and western
Colorado Tuesday night through Wednesday night under high
pressure which will keep the weather dry and quiet. As the
previous forecaster mentioned, under this stable environment
valley inversions should remain steady and temperatures will be
slow to warm. Upper level flow turns to the southwest on Thursday
as the next Pacific storm progresses into the Great Basin. The
wind gradient will tighten under the influence of a ~100kt
jetstreak which will result in a breezy afternoon on Thursday
which will help break any remaining surface inversions.
Precipitation will begin to spill into the region out ahead of an
approaching cold front Thursday night and continuing through
Friday as the cold front passes. The northern and central
mountains look to be favored with this system as the bulk of
support looks to be focused further north. Will have to hash out
snowfall totals over the coming shifts but preliminary amounts
look to reach 6 inches or so. Of course, any added instability and
forcing with the passage of the cold front could enhance snowfall
and vary amounts.

Behind the front on Friday, northwesterly flow will set up aloft
Friday night and into the weekend. This will result in generally
benign weather for Saturday and Sunday with no new disturbances
set to move into the forecast area.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 345 AM MST Mon Jan 22 2018

A few low clouds linger across the area as does some patchy fog.
In fact, KTEX is reporting IFR conditions at this hour due to some
light snow. These conditions will should end in the next few
hours, 15Z at the latest, giving way to VFR conditions for all TAF
sites. Variable clouds expected today with VFR conditions
anticipated though clouds will be thicker for KASE and KEGE as a
weak disturbance affects the northern mountains and, to a lesser
extent, the central mountains. ILS breakpoints may be reached at
both TAF sites from 00Z onwards as some lower ceilings move in.
Other TAF sites should remain above their breakpoints.




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