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National Weather Service Grand Junction Colorado
1051 am MST Thursday Nov 26 2015

issued at 920 am MST Thursday Nov 26 2015

Coordinated with weather forecast office pub in issuing a prolonged Winter Weather
Advisory for the southern San Juan Mountains through Saturday.
With the low pressure system stalled over the Great
Basin...moisture and energy will spin northeastward into the San
Juan Mountains in waves. The snow accumulation will be gradual
through the weekend except for the occasional snow burst. Breaks
in the snow will also be likely throughout the next few days.
Continued the advisory through 5pm Saturday for now with the
potential need to extend through Sunday.


Short term...(today through friday)
issued at 340 am MST Thursday Nov 26 2015

A huge upper level low will sit over Utah Thursday then
retrograde southwest to Southern California and Nevada Friday. The
surface cold front will be over southern Colorado Thursday then move
slowly south to New Mexico and Arizona Friday. A dry slot will
stretch across southeast Utah and SW Colorado and most of the significant
precipitation will occur over eastern Colorado...Wyoming and northern
Utah. Eastern Utah and western Colorado will be under moderate SW flow
aloft...and see plenty of clouds and cool temperatures...but the
precipitation will only be scattered and fairly light. The
mountains will see periods of snowfall but accumulations over a 48
periods will only range up to around 6 inches.

A change may start late Friday as the NAM predicts a shortwave
rounding the base of the western low and bringing a line of
precipitation into the San Juan Mountains.

Long term...(friday night through wednesday)
issued at 340 am MST Thursday Nov 26 2015

The closed low will meander across the Great Basin as cyclonic
flow (counter-clockwise flow) continues across much of the County Warning Area.
Models continue to highlight the San Juans for prolonged snowfall
thanks to southerly flow and favorable orographics. Highlights
looking more likely for zone 19 and possibly 18 but as has been
said time and again with this storm...any deviation of the
forecast low position will greatly change precipitation locations and
amts. Short range models are just now picking up on this possible
precipitation so a few more quick updates will certainly increase
confidence before issuing any highlights.

Outside of that area...some snow will fall for remaining mountains
along The Divide but still only expecting a few inches while
showers remain in the forecast for valleys. This period will be
rather unsettled as pieces of energy round the base of the low
pressure and as they move overhead...increased precipitation expected. A
strong wave looks to do this Saturday morning from south to north
exiting the area by Saturday evening. A repeat is expected Sunday
morning as the low pressure finally starts shifting to the north.

By Monday...finally...this pesky system will have moved off but
not much break as another weak wave sets its sights on our area.
This little disturbance will scoot by Tuesday afternoon through
early Wednesday morning. Expect some high clouds with some snow
over the mountains but minimal amts at best.


Aviation...(for the 18z tafs through 18z Friday afternoon)
issued at 1031 am MST Thursday Nov 26 2015

Unsettled weather is expected across the area today...however most
taf sites will remain VFR. Having said that...scattered rain showers/shsn
will cause periods of MVFR conditions at ktex...kase...kril...and
kege as the day progresses. There will not be much improvement
over the next few days as the system causing the precipitation will
linger to our west. Biggest impacts will be over the mountains with
periodic snow...low ceilings and visible. Mountains will be obscured
through the period.


Gjt watches/warnings/advisories...
Colorado...Winter Weather Advisory until 5 PM MST Saturday for coz019.



short term...cirrocumulus
long term...tgr

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