Area Forecast Discussion
Issued by NWS Pueblo, CO

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FXUS65 KPUB 230525

Area Forecast Discussion
National Weather Service Pueblo CO
1125 PM MDT THU SEP 22 2016

.SHORT TERM...(This evening through Friday)
Issued at 241 PM MDT Thu Sep 22 2016

...Windy and Unsettled Weather through Friday...

Current water vapor imagery and upper air analysis is indicating
moderate southwest flow aloft across the state, ahead of a deep
upper trough and low carving out across the Great Basin at this
time. Water vapor imagery is a minor short wave embedded within the
flow moving across northern New Mexico, with better moisture
associated with a strong upper jet rounding the base of the low
moving across western Utah at this time. At the surface, lee trough
across the eastern plains is keeping south to southeast winds and
low level moisture in place, with temps in the 80s to lower 90s
across the plains, with breezy south to southwest winds and temps in
the 50s to lower 70s across the higher terrain as of 2 pm.

Latest models remain in good agreement of increasing southwest flow
aloft across the state tonight, as the upper low moves into western
Utah. Strong south to southwest flow remains progged across the
state tomorrow, with the strong jet core moving across western
Colorado as the upper low lifts north and east into southwestern
Wyoming. Movement of this system keeps the best moisture, lift and
orographic flow for areas along and west of the ContDvd, especially
for the eastern San Juan and La Garita mountains, where rain and
higher elevation snow remains likely tonight and through the day
tomorrow. Temps aloft remain rather warm across the area tonight,
though still can not rule out a few inches of snow across the higher
peaks along the divide with increasing UVV and dynamic cooling.

Further east, should see isolated to scattered showers and storms
spreading east across the eastern mts and plains through the evening
with storms diminishing through the late evening and overnight hours
as mid level dry slot moves across the plains. SPC meso analysis has
CAPEs up to 1000 j/kg which would support a few possible stronger
storms across the plains this evening, with gusty winds and small
hail the main threats.

Flow aloft to keep lee troughing in place across the I-25 corridor
tonight, with breezy southerly winds keeping temps up, especially
across the far southeast plains and areas west of the corridor.
Models continue to support strong winds from aloft mixing down
across the plains through the late morning and afternoon, supporting
one last day of well above normal temperatures in the 80s to lower
90s across the plains. Lee trough and dry line lifts out across the
plains through the afternoon, with drying sw winds across the I-25
corridor leading to high fire danger. With that said, we have issued
a Red Flag Warning for all of the southern I-25 corridor including
El Paso, Pueblo, Huerfano, Las Animas, Crowley and Otero counties.
RH may be marginal for areas near the dry line, though will be close
enough to include, with the expected strong winds. With the dry line
pushing across the southeast plains, severe storms will remain
possible later in the afternoon and evening across the far southeast
plains, with damaging wind gusts and large hail possible.

.LONG TERM...(Friday night through Thursday)
Issued at 241 PM MDT Thu Sep 22 2016

Upper Trof axis swings through eastern Colorado Friday night with
thunderstorms continuing along the dry line across the eastern
border counties through the evening where the potential severe
thunderstorms will continue until around 02-03z. Then all activity
should shift east of the border around 06z. Very dry airmass moves
in behind the Red Flag conditions will persist into
the evening hours...though should end quickly after sunset as
winds relax and humidities come up. Clear skies and drier/cooler
airmass will set the stage for a potential widespread freeze
across the San Luis valley Friday night. Will hoist a Freeze Watch
as this may end up being the widespread killing freeze to end the
growing season. Otherwise...temperatures will be cooler Friday
night for the plains...but westerly winds should keep mins well
above the freezing mark.

Cold front moves through on Saturday which should knock high
temperatures back into the 70s across the plains...with a mix of 40s
50s and 60s for the high country.  Another upper jet digs down the
west side of the upper low...carving out the base of the trof
across CO and northern New Mexico through Sat evening. This sends
another reinforcing surge of cooler air into the area Saturday
evening with showers increasing from north to south across the
region...particularly across the mountains and I-25 corridor.
Doesn`t look like a great deal of moisture with this system...but
with H7 temperatures dropping to around 0 to -1C...certainly could
see localized snow amounts of an inch or two across the higher
peaks through Sunday morning.

Sunday looks like the coolest of the days with more cloud cover to
start out the day.  Models diverge with what happens to the southern
stream energy for Sunday and beyond...with EC cutting it off and
sending the broad upper low off to the southwest over NM Sunday
night...while GFS carries main energy off to the NE with a much
weaker reflection of the upper level trof moving southeastward
into eastern NM/west TX. Either way Sunday looks cool for southern
CO with only isolated showers and thunderstorms possible across
the mountains and southern portions of the area. Monday looks
drier and continued cool.

Extended models continue to diverge for Tuesday through Thursday
with GFS translating an upper ridge over the area with dry weather
and warming temperatures through the period. ECMWF lifts the
remains of the old upper low northward into the desert southwest
and eventually across UT and CO by mid to late week...suggesting
continued cool temperatures and increasing chances for showers and
thunderstorms across southern CO. Models have been split between
these two solutions over the last several confidence is
still rather low. Grids will play a compromise for now...with
isolated showers and thunderstorms returning to the forecast for
the mountain areas by mid to late week. -KT


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1117 PM MDT Thu Sep 22 2016

VFR conditions at all taf sites overnight and through the day on
Fri. Still a few -shra over the plains at 05z, but expect these
to stay mainly east of the taf sites overnight. S-SW winds will
be occasionally gusty through the night, with a brief lull 10z-
14z. Deep mixing will then develop across the area Fri, with
strong S-SW winds all locations by midday. Will likely see some
30-40kt gusts at all taf sites from early afternoon into the
evening, with high terrain gusts over 50 kts possible. Mountains
will see sct tsra in the afternoon/evening, with peaks obscured at
times, while a few stronger tsra will develop near the KS border
toward 00z, then move east of the area by 03z-04z.


.PUB Watches/Warnings/Advisories...
Red Flag Warning from noon to 8 PM MDT Friday for COZ226>233.

Freeze Watch from late Friday night through Saturday morning for



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