Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Pueblo Colorado
402 am MDT sun Apr 26 2015

Short term...(today and tonight)
issued at 346 am MDT sun Apr 26 2015

..Spring storm to bring significant precipitation to the east slopes of
the southern mountains and immediate adjacent plains along with the
Raton Mesa region...


Full latitude trough was located from north Idaho...southward all the way down
into old Mexico. System was just about to begin to close off across
NE ariz based on latest Short Run hi res prgs. Across the
region...warm air advection was firing off convection from just north of kcos into
northeast Colo. Low ceilings were developing across the southeast Colo plains.
Moisture was not an issue with this system as 50 dewpoints were noted
over the far southeast Colo plains and this moisture was advancing westward
towards the mountains


Latest guidance is now indicating the storm track will be a bit
farther south than earlier runs. This will mean that the heaviest
quantitative precipitation forecast will be a bit farther south and west. It appears that the plains
generally east of I-25 and areas north of the Las Animas/Baca County
borders will not see as much precipitation as earlier projected.
However...we do expect very heavy precipitation to fall over the Wet
Mountains...the sangre Delaware cristo mountains and the nearby valleys. The
immediate plains adjacent to these mountains will also see impressive quantitative precipitation forecast

Elsewhere for today...the Continental Divide region will see 5 to 10 inches of
snow...however valley regions should be predominantly rain with this
event given the slightly farther southern track.

The brunt of the heavy precipitation will likely develop after noontime
along the east slopes of the S mountains snow will fall at the highest
elevations of the sangres/wets around noon and will gradually work
downward in elevation as the late afternoon progresses. One to 2
feet of snow is very likely at the highest elevations. The snow will
be very wet.

There is a chance we could see some stronger storms over the Raton
Mesa region mainly during the early to middle afternoon time periods.
Thunder will be possible everywhere today...especially during the

The Pikes Peak region will see some decent precipitation. All of the
guidance strongly focuses the precipitation on the immediate east slopes of
Pikes Peak and the Rampart Range...with significantly lesser amounts
across the western sections of Teller County. Snowfall values across
far west El Paso County and Teller County will likely vary
considerably....with highest amounts east slopes and (much)
lesser amounts west slopes.

The San Luis valley will also see beneficial rainfall amounts late

A quick review of hilites...advisories are currently in effect for
the Continental Divide. Warnings go into effect for the tops of the
sangres...wets and Pikes Peak at noon. Warnings go into effect for
the lower elevations of the sangres and wets at 4 PM. An advisory
GOES into effect for the lower elevations of Teller County at 4 PM.
An advisory GOES into effect for Huerfano and lower western Las
Animas counties after 8 PM this evening. This area is going to be
very tricky as the west sections of these zones may see warning criteria
while eastern sections of these zones will likely see only rain. Without is a very difficult forecast for these areas. The Wet Mountain
Valley also has an advisory starting after 8 PM. This area will also
have to be watched carefully.


Heavy rain and snow will continue across the S mountains...especially the
wets and sangre Delaware cristos along with the Raton Mesa region tonight.
Storm total liquid quantitative precipitation forecast for these regions will likely range between 2
and 3 inches.

The lowest rain/snow line will likely reach 6000 feet south of
Pueblo...with the "significant accumulating snow elevation" likely
beginning around ~7500 feet.

Precipitation across the Pikes Peak region will likely decrease by late
evening. One to 3 inches of snow will be possible across northern El
Paso County tonight. \/Hodanish

Long term...(monday through saturday)
issued at 346 am MDT sun Apr 26 2015

Models in decent agreement through the extended period but have
shown low run to run consistency and ensembles having high spreads
further out in the extended period.

Monday...the upper level low responsible for the widespread and
locally heavy precipitation is forecast to track eastward out of
east central New Mexico into western Oklahoma through Monday
night. Strong and moist low level upslope will continue to produce
moderate to heavy rainfall and high elevation snow for the eastern
mountains and areas along the New Mexico border. Snow levels will
remain high...7 kft and up...and the primary focus Monday over the
Wet Mountains and southern sangre Delaware cristo ranges. An additional
4 to 6 inches of snow are possible Monday morning before tapering
off during the late afternoon. Models still indicating areas along
the New Mexico border will continue to see heavy rain through much
of the day Monday. An additional up to half an inch is expected.
Elsewhere...periods of snow will continue along the higher
elevations of the Continental Divide...the northern sangre Delaware
cristo mountains and Teller County with a couple of inches of
additional accumulation expected. Lighter rainfall will continue
over much of the plains north of Highway 50 throughout the day.
Temperatures will be cool with 40s and 50s across the region.

Models in good agreement with precipitation coming to an end from
north to south Monday evening as the upper low moves into
Oklahoma. Expect any lingering activity to dissipate Monday night
into early Tuesday morning.

Tuesday and Wednesday...high pressure over the Great Basin will
build eastward into The Rockies. This will bring drier conditions
to the region and allow temperatures to begin warming up. A few
afternoon and evening showers and thunderstorms are possible over
the mountains. Temperatures will reach the 6os and 70s.

Thursday through Saturday...ensemble spreads begin to rise sharply
by Thursday however the GFS and European model (ecmwf) are in decent agreement with
a shortwave trough moving out of the northern rockies into the
northern plains. The ensembles generally support this...however
there are a few solutions with a deeper and faster moving system.
As for the forecast...currently think the system will pass well to
the north...but flatten the ridge overhead with zonal flow taking
over. This should allow for greater shower and thunderstorm
coverage over the mountains each afternoon...and westerly steering
flow should allow for this activity to push east into the eastern
plains during the evening hours. Temperatures will also warm with
highs in the 70s and 80s. Mozley


Aviation...(for the 12z tafs through 12z Monday morning)
issued at 346 am MDT sun Apr 26 2015

MVFR/IFR conditions will develop within the next couple of hours at
kcos and kpub due primarily to low ceilings. Precipitation will likely restrict
visible in the MVFR category. These conditions will likely last for the
next 24h. The precipitation should be liquid throughout the event.

We may see restricted visible/ceilings at kals...with the best chance of
restrictions from the middle afternoon time period through middle evening
as this will be the best time for precipitation in the valley. Most...if
not all...of the precipitation should be liquid.


Pub watches/warnings/advisories...
Winter Weather Advisory from 8 PM this evening to noon MDT
Monday for coz087-088.

Winter Storm Warning from 4 PM this afternoon to noon MDT Monday
for coz072-074-079.

Winter Weather Advisory from 4 PM this afternoon to noon MDT
Monday for coz076-078-081.

Winter Weather Advisory until 6 am MDT Monday for coz058-060-061-

Winter Storm Warning from noon today to noon MDT Monday for



Short term...hodanish
long term...mozley

National Weather Service Glossary of Abbreviations