Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 232156

Area Forecast Discussion
National Weather Service Denver/Boulder CO
356 PM MDT Fri Sep 23 2016

.SHORT TERM...(This evening through Saturday)
Issued at 311 PM MDT Fri Sep 23 2016

A strong upper level low was over northern UT this aftn with
moderate QG ascent over CO at this time. A strong southerly flow
associated with a 100+kt jet overhead. This features will shift
over eastern CO this evening then lift northeast into Nebraska
Saturday morning. Good lift coupled with aftn instability has
allowed for a mix of rain showers...snow showers and thunderstorms
in the mountains this aftn. Precipitation will increase in the
mountains this evening. Mid level winds will be south/southwesterly
tonight...then west/northwesterly on Saturday. No much qg support
for snow in the mountains late tonight but good orographics. Have
gone ahead and issued a winter weather advisory for snow/blowing
snow for zone 31 from midnight to 10 am saturday morning. low
vsbys in exposed areas above timberline tonight and saturday
morning in snow/blowing snow. Across the northeast plains...gusty
southerly winds will transition to northerly this evening. Red
Flag Warning continues for areas east and south of Denver until 8
pm this evening. Isolated thunderstorms this evening but the best
chc will be along the northern border. one or two could produce
very strong winds toward Wyoming and Nebraska. As the upper low
moves into central Wy tonight...then wrap around moisture may
allow for another round of showers/tstms along the northern border
overnight. Cooler on Saturday and generally dry across the
northeast plains. Best chc of any showers on Saturday will be
near the foothills and palmer divide. A mix bag of rain and snow
showers in the high country saturday aftn.

.LONG TERM...(Saturday night through Friday)
Issued at 311 PM MDT Fri Sep 23 2016

The upper level low will be over Wyoming on Saturday with wrap
around moisture continuing to bring precipitation to the mountains
through Saturday afternoon. Temperatures will be cold enough to
bring a few inches of snow accumulation along Rabbit Ears
Pass...particularly the western slopes with snow spreading over
the Northern mountains by the late morning. Instability and
lingering moisture will keep a slight chance of precipitation
through Saturday evening for the higher mountains and adjacent
plains. Mountain wave energy that helped to bring increasing
downslope winds into Friday night will diminish by Saturday
morning but strong westerly flow aloft will continue to produce
wind gusts up to 40 mph at mountain top through the morning.
Elsewhere on the plains clouds will increase through the day with
cooler temperatures on continuing cold advection.

Both the GFS and EC show a piece of the energy associated with the
upper low breaking off and diving to the SW near the US and
Mexico border by Monday. Then for Sunday through the middle of
next week an upper ridge that was over the west coast will make
its way east helping to stabilize the airmass over CO. This will
bring a prolonged dry period but with continued cool temperatures.
Highs will be in the upper 60s to 70s into next week.

For the low to the south models are showing that the ridge will
move off to the east allowing for the now trough to move over CO
bringing another chance of precipitation to the region but under
slightly warmer temperatures then earlier in the week.


.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 311 PM MDT Fri Sep 23 2016

Generally VFR conditions expected with bkn mid level cigs. Strong
southerly winds until 01z then northwest/northerly winds as sfc
trough shifts to east central CO. Surface winds slowly transition
to south/southwesterly after 10z Saturday morning. Best chc of
showers will be north of Denver so will not include them in the
local Denver terminals at this time.


Issued at 311 PM MDT Fri Sep 23 2016

Strong southerly winds with rh values fm the teens to low 20s this
aftn. Will continue with the Red Flag Warning until 8 pm this


Red Flag Warning until 8 PM MDT this evening for COZ240-241-

Winter Weather Advisory from midnight tonight to 10 AM MDT
Saturday for COZ031.



LONG TERM...Dankers
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