Area Forecast Discussion
Issued by NWS Pueblo, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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
FXUS65 KPUB 151109

Area Forecast Discussion
National Weather Service Pueblo CO
409 AM MST Fri Dec 15 2017

.SHORT TERM...(Today and tonight)
Issued at 343 AM MST Fri Dec 15 2017

Current water vapor imagery and upper air analysis is indicating
drier air embedded within moderate northerly flow aloft moving
across south central and southeast Colorado, with a large upper
ridge in place across the West Coast through the Intermountain West.
Water vapor imagery is also indicating Pacific moisture topping the
ridge ahead of system moving onshore across the Pac NW at this time.
At the surface, late night low clouds and patchy fog had developed
across portions of the Pikes Peak Region, the San Luis Valley and
the Mid Arkansas River Valley, though the drier air mixing across
the area has helped to dissipate some of the stratus, with the
GOES16/East fog product still indicating stratus/fog along and north
of Highway 50, between Pueblo and the Otero/Crowley County line.

Today and Tonight...Northerly flow aloft moderates through the day
and becomes more westerly into tonight, as Pac Northwest system
flattens the upper ridge as it translates into the Great Basin
Region overnight. Dry weather is expected today, with warming aloft
under the west to northwest flow aloft helping to boast temperatures
back to above seasonal levels, with highs in the 50s to lower 60s
expected across the the lower elevations, and mainly in the 30s and
40s across the higher terrain. Will see some breezy westerly winds
over and near the higher terrain today and tonight, leading warmer
overnight lows across the area tonight.

.LONG TERM...(Saturday through Thursday)
Issued at 343 AM MST Fri Dec 15 2017

...Roller coaster temperatures with a couple chances for light
freezing/frozen precipitation...

Upper trof will be approaching CO from the west on Saturday.  Still
a nice day ahead of the system but cold front will moving through
the plains during the morning. Initially front is dry, but
overnight as the upper trof shifts eastward, low levels start to
saturate as shallow upslope flow develops. With majority of the
forcing with the incoming trof dropping southward as an upper low
closes off and drops into southern AZ and northern Mexico,
precipitation along the lower eastern slopes of the southeast
mts/adjacent plains will be forced by shallow upslope. Depending
on depth of saturation, portions of the I-25 corridor and
southeast plains could see some light freezing drizzle late
Saturday night into Sunday morning. For now, most likely area
will be Palmer Divide and perhaps Kiowa county where cold
saturated airmass may saturate the deepest. Even for these areas
any ice accumulation looks spotty and very light at this point so
not anticipating any highlights.

Temperatures on Sunday will remain around or below climo.  There
will be some snow showers across the mountains through the day, but
with energy splitting as it moves across the area, accumulations
will remain light. Skies clear out behind the system Sunday night
though NW flow may start to spread mid/high cloudiness back into
northern sections of the area towards dawn. Guidance is quite cold
and given dry cold airmass over the area, have dropped back
temperatures quite a bit over model blends, putting MinTs in the
cold valley areas closer in line with guidance.

It dries out and warms up into next week. Will have to watch
Wednesday for a potential critical fire weather day as southwest flow
aloft increases ahead of the next upper trof dropping in from the
northwest. ECMWF is a little faster than GFS though both suggest
a similar scenario with a quick hitting chance for snow Wednesday
night/Thursday along with much colder air. H7 temperatures on
Friday will be around -10C which would will put highs potentially
in the 30s for most areas. This could be just a taste of what`s
to come as GFS suggests another system will drop in from the
north sending our first really cold spell into the area on
Saturday. ECMWF is much warmer and thus confidence is low at this
point, so will have to see how the models trend over the next
several days. -KT


.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 343 AM MST Fri Dec 15 2017

Patchy morning fog at PUB will continue to diminish by 12Z, as drier
air within the northerly flow aloft continues to filter into the
region. Otherwise, VFR conditions and generally light diurnal wind
regimes are expected over the next 24 hours at COS, PUB and ALS.




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