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Area forecast discussion 
National Weather Service Pueblo Colorado
526 am MDT Sat may 23 2015

issued at 510 am MDT Sat may 23 2015

Updated to adjust probability of precipitation over the southeastern plains for this
morning. Radar has filled in nicely with a broad area of light
precipitation and embedded thunderstorms moving northeast of a
Trinidad to Haswell line. Light rain is most likely falling over
most of this area...however brief heavy downpours and pea size
hail may be falling out of stronger cores. Mozley


Short term...(today and tonight)
issued at 358 am MDT Sat may 23 2015

..severe weather expected this afternoon...

Ingredients are coming together severe weather this afternoon and
evening across portions of the eastern plains.

Currently...a large upper level low pressure center is currently
sitting over southern Utah with energy moving northward out of New
Mexico and into southern Colorado. Showers and isolated
thunderstorms have been developing along and east of the sangre Delaware
cristo mountains...from near San Luis...northeast to Colorado City.
Light to moderate rainfall...and pea size hail are possible with
these showers and thunderstorms. An mesoscale convective system of northeastern New Mexico
is moving northeast and will clip our far southeastern zones through
8 am. Temperatures have been mild overnight with 50s across the

Today...very dynamic set up for late this morning through this
evening. The upper level low will slowly drift northward across
Utah sending a strong wave of energy north across Colorado. Models
in very good agreement with expected forecast evolution. Expect
continued shower and isolated thunderstorm activity this morning
over the mountain areas and adjacent plains. Heavier showers and
thunderstorms will move north out of New Mexico and across
Baca/Prowers counties this morning clearing into Kansas around 8 am.
As the morning progresses...a dryline is forecast to develop as
drier air wrapping around the main upper low moves into south
central Colorado. High-res models have the dryline setting up from
near Fountain...southeast toward Kim by 11 am and convection rapidly
developing through noon. Moisture ahead of the dryline is deep with
dewpoints in the middle 50s and cape values are expected to reach in
the 1500-2000 j/kg range along and ahead of the dryline this
afternoon. Shear is also quite strong...around 6 kts through 6 km.
This should allow for strong rotating updrafts with cells that fire
along the dryline. The main threats will be lightning along with
hail larger than one inch in diameter and locally heavy rainfall.
Given the shear profiles...there will be a tornado threat. Models
all have the greatest threat for severe weather north and east of a
Pueblo to Kim line...and several of the high-res model
solutions...hrrr/rap/NAM supercell development near
Colorado City and lifting northeast across Pueblo and into Lincoln
County. In addition to the large hail and tornado threat...heavy
rainfall will occur with thunderstorms. Already saturated ground
conditions and rivers/streams running high could lead to additional
flash flooding and river flooding across all of the region. If you
encounter flooding on roadways...remember...turn around...don't

Across the mountains...showers will continue through the day. Pea
size hail is likely with thunderstorms that develop and locally
heavy rainfall could lead to flash flooding...especially on burn
scars. Snow will remain confined to above 10 kft with an inch or
two possible through this afternoon.

Tonight...the upper low over Utah will continue into Wyoming with a
trough stretching to The Four Corners region. Dry air wrapping
around the low will continue to spread across the eastern plains
this evening lifting the thunderstorm activity north and east
through the evening hours. The severe weather threat will likely
continue this evening...generally north of Highway 50 and clear the
area by midnight. Shower activity will continue across the
mountains with increasing coverage late tonight into Sunday morning
as the next wave moves into western Colorado around the upper low.
Snow levels will remain high...with a few inches possible above 9
kft by Sunday morning. Mozley

Long term...(sunday through friday)
issued at 358 am MDT Sat may 23 2015 pattern to continue...

Upper low will track across northern Colorado on Sunday. This
track will favor the central mountains and Pikes Peak region with
the best precipitation chances...falling as rain showers at the
lower elevations and snow above 9000 feet. Thunderstorms will be
mixed in with most of the activity diurnally driven...occurring
during the afternoon and evening hours.

Yet another wave will drop southeast across the area Monday afternoon
and evening for an encore performance. Another round of afternoon
and evening showers...thunderstorms...and snow above 9000 feet is

A shortwave ridge will move over the area Tuesday and Wednesday.
However...the models are certainly not killing all of the
afternoon and evening shower and storm threat. They do tend to
keep most of the activity over and near the mountains these 2
days...but there is still some activity indicated to move east
across the plains...especially north of Highway 50...and
particularly along the Palmer Divide.

Thursday and Friday are pretty questionable right now. Old runs
had another closed low circulation passing east across Colorado
during the period pulling substantial southern moisture up into
the region. However...the 06z run of the GFS just in now shows a
progressive westerly flow...with no closed circulation. The end
result is much less widespread precipitation from Thursday
afternoon through Friday. There is still convection indicated
Thursday afternoon but mainly over the mountains and far southeast
plains. Then on Friday...a weak wave brings a strong cold front
down through the eastern plains...generating low level upslope
flow...with convection developing behind the front along the
Palmer Divide during the afternoon. Finally on Friday night...the
precipitation spreads southward...encompassing all of the eastern
slopes and plains. Interesting change from earlier runs. Could be
just a fluke of the intermediate 06z run. We will see.


Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 358 am MDT Sat may 23 2015

Kals...VFR conditions forecast through the next 24 hours. A few
showers have been moving north over the eastern portions of the San
Luis valley but do not look to impact the terminal at this time.
Gusty southwest winds are expected this afternoon with gusts in
excess of 25 kts likely. Showers and thunderstorms are forecast
over the mountains this afternoon and evening...but do not look to
impact the terminal at this time.

Kcos...VFR conditions this morning. Thunderstorms are forecast to
develop by early afternoon and impact the terminal through this
evening. Large hail and heavy rainfall along with lightning will be
the main threats with thunderstorms at the terminals. Lowered ceilings
and visible to IFR-LIFR are expected as thunderstorms pass. The most
likely time frame for thunderstorms at kcos will be from 19z through

Kpub...VFR conditions this morning. A few showers have been
dissipating south of the terminal and will likely not impact the
area this morning. Thunderstorms are expected to develop by late
morning to early afternoon and impact the terminal through this
afternoon. Large hail...heavy rainfall and lightning will be the
main threats as thunderstorms pass. Lowered ceilings and visible to IFR-
LIFR are expected with thunderstorms. Thunderstorms will likely
impact the terminal after 17z and through 00z/sun. Mozley


Pub watches/warnings/advisories...


short term...mozley
long term...lw

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