Severe Thunderstorm Warning 438, NWS Pueblo, CO

414 
WWUS55 KPUB 202110
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Severe Weather Statement
National Weather Service Pueblo CO
310 PM MDT Thu Jul 20 2023

COC071-202130-
/O.CON.KPUB.SV.W.0438.000000T0000Z-230720T2130Z/
Las Animas CO-
310 PM MDT Thu Jul 20 2023

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM MDT
FOR SOUTHWESTERN LAS ANIMAS COUNTY...

At 310 PM MDT, a severe thunderstorm was located over Boncarbo, or 8
miles northwest of Trinidad, moving east at 20 mph.

HAZARD...Torrential rainfall, 60 mph wind gusts, and half dollar 
         size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Trinidad, Cokedale, Starkville and Boncarbo. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3716 10473 3731 10471 3736 10444 3709 10444
TIME...MOT...LOC 2110Z 270DEG 16KT 3723 10465 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Ehr

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Severe Weather Statement
National Weather Service Pueblo CO
328 PM MDT Thu Jul 20 2023

COC071-202137-
/O.EXP.KPUB.SV.W.0438.000000T0000Z-230720T2130Z/
Las Animas CO-
328 PM MDT Thu Jul 20 2023

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN LAS ANIMAS COUNTY
WILL EXPIRE AT 330 PM MDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However heavy rain
is still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
southeastern Colorado.

LAT...LON 3716 10473 3731 10471 3736 10444 3709 10444
TIME...MOT...LOC 2127Z 270DEG 16KT 3723 10456 

$$

Ehr

Area Forecast Discussion
National Weather Service Pueblo CO
1217 PM MDT Thu Jul 20 2023

.UPDATE...
Issued at 1215 PM MDT Thu Jul 20 2023

Bigger updates this morning were with an increased likelihood for
more discrete supercellular development over much of the plains from
the I-25 corridor and east, along with an increased risk of tornadic
development. This increased tornado risk includes all areas across
the plains from the I-25 corridor to the east.

Relatively quiet at the moment, with only some very isolated light
showers developing over the mountains. This will quickly change
around the 1pm time frame, as upstream thunderstorm development as
well as development over the mountains increase. This will be in
response to an approaching mid level wave, low level moist upslope
flow, as well as backing 700mb flow. This increased large scale
ascent and deeper upslope flow with strengthening convergence should
allow this development to then spill into the I-25 corridor by early
to mid afternoon where it will encounter a highly unstable
environment, high shear, and backing low level flow. This will
support the development of widely scattered supercells capable of
producing large hail, destructive winds, and a few tornadoes. The
backing low level flow with rapidly increasing mid level flow is now
showing higher increases in helicity. This is concerning as it will
support the above mentioned increased tornado risk, which includes
all of the I-25 corridor and quite possibly even Teller and eastern
Fremont counties.

By mid to late afternoon, most of the storms are expected to move to
the eastern plains, though some guidance continues additional
development across parts of the Pikes Peak region and I-25 corridor
during this time. Given the high amount of instability and moisture,
don't see any reason why the severe threat won't continue in these
areas later in the afternoon into the evening. For the eastern
plains, have changed previous thoughts on these storms congealing
into a line and transitioning the main risk to a wind risk. Latest
guidance now supports the continued development of more discrete
supercells capable of all hazards including the risk of tornadoes.
So, while destructive winds are still possible, the expected trend
will be for supercells to continue moving across the eastern plains
later this afternoon into the evening. Once again, an increased
tornado risk due to similar backing low level flow and increasing
flow aloft.

By mid to late evening, focus for additional thunderstorm
development looks to be over the far eastern plains where the low to
mid level trough looks to stall. This will then support an
increasing flash flood risk, where the current Flash Flood Watch is
in effect. Closer to the midnight time frame, development should
begin to really diminish, though a few storms capable of producing
heavy rain will remain possible over the eastern plains.

&&

.SHORT TERM...(Today and tonight)
Issued at 408 AM MDT Thu Jul 20 2023

Key Messages:

1) Active weather day expected, with severe storms likely from I-25
eastward across the plains.

2) Environment will be favorable for supercells with large hail
(golfball to baseball size) and strong winds (gusts to 75 mph), and
at least a low tornado risk along I-25 early in the afternoon as
initial cells spin up.

2) Heavy rain/flash flood risk increases today, especially over the
eastern plains where pockets of heavier rainfall occurred yesterday.

Currently, storms already firing over north central CO as of 330 am,
as lead piece of short wave energy races eastward ahead of main
upper wave back over Utah. Expect this activity to stay mainly north
of the area early this morning, and included just some low pops for
northern zones to account for any brief srn extension of convection.
Main convective show gets going around midday, as upward vertical
motion increases across Colorado with upper wave moving into the
nwrn part of the state. Environment looks primed for severe
convection, with low level sely winds strengthening by afternoon in
response to falling pressure over the mountains, before late
arriving cold front begins to sweep through the area in the early
evening. Pre-storm CAPE values rise into the 1500-2500 J/KG range
over most locations along and east of I-25, while 0-6km shear is a
healthy 40-50 kts. If CAMs are correct, initial storms fire over nrn
sections/Palmer Divide in the early afternoon, then activity builds
southward along I-25 through mid-afternoon. Last couple runs of the
NAMnest and HRRR depict a persistent helicity swath/potential
supercell dropping southeastward from Monument through eastern El
Paso County through the afternoon, and this may be one area to watch
for potential tornado development, along with the risk for very
large hail as well. Storms become widespread from late afternoon
into the evening from the mountains eastward, leading to an
increasing strong wind and heavy rainfall threat on the plains, as
cold front sweeps southward and perhaps organizes convection
somewhat. Have issued a flash flood watch for all of the southeast
plains east of I-25 for this afternoon and tonight, and areas along
and south of Highway 50 which saw heavy rain/flash flooding
yesterday may be especially susceptible to additional run-off
problems.

Farther west over the mountains and interior valleys, convection
will be weaker and more scattered in nature, though a few strong
storms with gusty winds/small hail look possible as upward motion
increases through the day. Storms gradually end/shift eastward into
KS by late evening, though again a few CAMs keep some activity going
on the plains past midnight, as convective outflows force at least
scattered storms behind the departing main band. Clouds may be slow
to clear overnight given precip and persistent sely outflows, though
most precip should at least be done by sunrise on Fri.

.LONG TERM...(Friday through Wednesday)
Issued at 408 AM MDT Thu Jul 20 2023

Key messages:

1) Cooler and relatively drier on Friday, scattered showers and
thunderstorms are expected, mainly over the eastern mountains and
along the I-25 corridor. Some of these storms may contain hail
greater than an inch in diameter and wind gusts of 60 mph or greater.

2) Even overall drier on Saturday. A few thunderstorms will develop
during the afternoon and evening over the higher terrain. Plains
will be dry and warmer.

3) Better chance for afternoon and evening thunderstorms on Sunday,
mainly over the higher terrain, although a few storms could move out
into the plains.

4) Thunderstorm activity will begin to ramp back up again beginning
early next week and through the rest of the week over the inner
mountain west, with increasing chances of thunderstorms each day
over the Continental Divide as the monsoonal pattern becomes more
pronounced.

5) Thunderstorm chances over the plains for next week look to be
more favorable as the week progresses, as there will be increasing
thunderstorm coverage with better westerly flow aloft.

6) Cooler on Friday, followed by a gradual warmup going into early
next week with above average temperatures returning again by Sunday.
Monday will be the hottest day of the week with near record
temperatures possible. There will be a slight cooling trend
thereafter, although temperatures are expected to remain above
average.

Detailed discussion:

Friday...

A few showers will be possible during the early morning hours on
Friday over portions of the plains as there will be a light easterly
upsloping wind component in place. In addition, the HRRR is also
showing a weak boundary of low level convergence over the eastern
plains near Highway 50 by around 6 AM, so it is also possible for
there to be a few rumbles of thunder over this area. Broken to
overcast skies will begin to clear through the late morning hours,
which will help to destabilize the lower levels depending on how
quickly clouds dissipate. Dewpoints will likely remain in the 50s
all the way up against the eastern mountains throughout the day,
which will set the stage for a conditionally unstable environment
over the plains by later in the afternoon.

Cooler air with northeasterly winds at the surface will keep the
plains around 10 degrees below the seasonal average. As a result,
temperatures will become noticeably cooler over the plains,
especially the further north and east you go. Some locations over
the northern and eastern plains may not even reach the 80 degree
mark. The higher terrain will be relatively warmer in comparison to
the plains, with the San Luis Valley likely being slightly warmer
than the plains for most locations. There will be some drier air
being advected in behind the shortwave with northwesterly flow in
the mid-levels. Although with weak troughing still in place, this
will help to initiate convection. Because of this, isolated to
scattered thunderstorms will develop by afternoon, confined mainly
over the eastern mountains. Model guidance still shows the southern
Sangre de Cristo Mountains having the highest QPF as previous runs
have persistently expressed. Some of these will move off over the
adjacent plains and into the I-25 corridor, however, there will be a
lot of CIN (capping) so this could hinder further development and
could allow for storms to weaken as they move further east.

The plains will be more relatively stable in comparison to Thursday,
so chances are that storms will become severe are not as high,
although there will still be some sufficient CAPE and shear over the
the plains in Teller County, eastern El Paso County, the Sangre de
Cristo Mountains, and southern I-25 corridor/Raton Mesa. Therefore,
a few of the storms that move over these areas could become strong
to severe. CAMs display that the best MUCAPE will be located over
the border of El Paso and Lincoln counties, as well as over the
southern Sangres of nearly 2000 J/kg. The best effective bulk shear
will be over the southern Sangres of around 50 kts. Given these
values, I have the highest confidence in a storm developing over the
Mt. Blanca/Spanish Peaks region, then becoming strong or even severe
as it moves southeastward over the La Veta Pass/highway 12 area and
eventually in the vicinity of Aguilar and Trinidad. Wind and hail
will be the main threats with these storms, as well as torrential
rainfall. Once again, WPC has southeastern Colorado in a marginal
excessive rainfall for Friday and the burn scars (namely the Spring
Burn Scar) of the eastern mountains could be at risk of flash
flooding.

Saturday through Sunday...

As the shortwave exits the region, the ridge is going to continue to
strengthen over the Four Corners region in its wake, and this will
slowly propagate eastward over central Colorado throughout the
weekend. As it does, there will be greater subsidence in place which
should prevent much in the way of thunderstorm development as mid-
levels appear to be mainly dry on Saturday over the region.
Northwesterly flow aloft will also be generally on the weaker side,
so only a few storms that initiate with the help of orographics will
likely not hold together for very long and collapse as they move off
the mountains. Conditions will be quite stable over the plains in
the low levels with a lot of capping in place, and in the mid
levels, the better CAPE and shear will be pushed further east over
Kansas. With this in mind, the plains should remain dry for the most
part, and there should only be a few storms over the higher terrain.
The areas that are most unstable and have the best chances of
convection will be over the southern mountains. An isolated storm
may develop over the Spanish Peaks and move over into the southern I-
25 corridor, or perhaps in vicinity of the Raton Mesa, but this
appears to be the only areas for the plains that may have a
thunderstorm move over by late afternoon on Saturday. Temperatures
will also be much warmer for the plains, back near the average for
this time of year.

The building ridge will continue the steady temperature rises back
above the seasonal average again by Sunday, especially for the
lower mountain valleys and plains. There will be some better
moisture advection moving in over the region into the mid to upper
levels around the clockwise flow of the high from monsoonal
moisture plume upstream on Sunday, therefore thunderstorm coverage
will likely be better over the higher terrain. Because of
slightly better westerly flow, a few of the storms could move off
into the I-25 corridor, although the lower levels with
southwesterly winds at the surface will remain relatively dry and
quite capped, so storms will likely weaken quickly as they move
off the mountains and over into the adjacent plains.

Monday through Thursday...

It will be very hot on Monday, with near record high temperatures
for some locations as the ridge is at its peak intensification with
nearly 600 dm of a 1000-500mb thickness value parked right over
Colorado. Locations over the plains will especially be vulnerable to
the excessive heat and there will most likely be heat advisories in
place for quite a few locations as temperatures could reach the mid
100s for the lower Ark Rvr Valley. Only a slight cooling trend will
occur from Tuesday through Thursday as the ridge becomes more
flattened with some weak troughing to the north of the region,
although temperatures will likely remain above the seasonal average
for most locations through the remainder of the forecast period.

Ensemble members of both the EPS and GEFS have been showing
increasing PWAT values over the inner mountains, especially the
ContDvd through the course of the week as there is a better
monsoonal pattern becoming established. Deterministic models also
have been consistently showing an uptick in the moisture plume
between the 700 to 500 mb level. Given the increasing amount of
moisture, and warmer temperatures, afternoon and evening
thunderstorm coverage will likely increase next week over the higher
terrain, with a better chance for storms over the ContDvd and inner
mountain valleys. There will also be increasing chances for storms
over the plains as the week progresses, due to better thunderstorm
coverage over the higher terrain and also increasing westerly flow
in the mid to upper levels as troughing to the north slowly deepens
and forces the ridge axis to become more positively tilted.  -Stewey

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1215 PM MDT Thu Jul 20 2023

KCOS and KPUB...Latest CAMs continue to show stronger convection
developing around 20Z and continuing for a few hours before moving
southeast of the region. Outflows from these storms striking the
higher terrain could result in some convection during the evening.
CAMS tend to overdo the strength of the outflow convection and
just have VCSH in TAFs versus VCTS. Expect lower to develop from
easterly outflow winds and kept ceilings at VFR overnight with
lower clouds dissipating mid morning Friday.

KALS...VFR. Chances for high based convection in the afternoon is
fairly low so have only VCTS in TAFs. Storms could produce gusty
outflow winds. There could be a period of easterly winds overnight
as outflow shoots through the gaps in the mountains east of KALS.
--PGW--

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Flood Watch through late tonight for COZ089-093>099.

&&

UPDATE...RODRIGUEZ
SHORT TERM...PETERSEN
LONG TERM...STEWARD
AVIATION...PGW

Hazardous Weather Outlook
National Weather Service Pueblo CO
1229 PM MDT Thu Jul 20 2023

COZ058>089-093>099-211830-
Western Mosquito Range/East Lake County Above 11000 Feet-
Leadville Vicinity/Lake County Below 11000 Feet-
Eastern Sawatch Mountains Above 11000 Feet-
Western Chaffee County Between 9000 and 11000 Feet-
Central Chaffee County Below 9000 Feet-
Western Mosquito Range/East Chaffee County Above 9000 Feet-
Saguache County West of Continental Divide Below 10000 Feet-
Saguache County East of Continental Divide Below 10000 Feet-
La Garita Mountains Above 10000 Feet-
Upper Rio Grande Valley/Eastern San Juan Mountains Below
10000 Feet-Eastern San Juan Mountains Above 10000 Feet-
Del Norte Vicinity/Northern San Luis Valley Below 8500 Feet-
Alamosa  Vicinity/Central San Luis Valley Below 8500 Feet-
Southern San Luis Valley-
Northern Sangre de Cristo Mountains Between 8500 And 11000 Feet-
Northern Sangre de Cristo Mountains Above 11000 Feet-
Southern Sangre de Cristo Mountains Between 7500 and 11000 Feet-
Southern Sangre de Cristo Mountains Above 11000 Feet-
Northwestern Fremont County Above 8500 Feet-
Western/Central Fremont County Below 8500 Feet-
Wet Mountain Valley Below 8500 Feet-
Wet Mountains between 6300 and 10000 Feet-
Wet Mountains Above 10000 Feet-
Teller County/Rampart Range Above 7500 Feet/Pikes Peak Between
7500 And 11000 Feet-Pikes Peak Above 11000 Feet-
Canon City Vicinity/Eastern Fremont County-
Northern El Paso County/Monument Ridge/Rampart Range Below
7500 Feet-
Colorado Springs Vicinity/Southern El Paso County/Rampart Range
Below 7400 Feet-Pueblo Vicinity/Pueblo County Below 6300 Feet-
Walsenburg Vicinity/Upper Huerfano River Basin Below 7500 Feet-
Trinidad Vicinity/Western Las Animas County Below 7500 Feet-
Crowley County-La Junta Vicinity/Otero County-
Eastern Las Animas County-Western Kiowa County-
Eastern Kiowa County-Las Animas Vicinity/Bent County-
Lamar Vicinity/Prowers County-Springfield Vicinity/Baca County-
1229 PM MDT Thu Jul 20 2023

This hazardous weather outlook is for portions of central...east
central...south central and southeast Colorado.

.DAY ONE...This Afternoon and Tonight

Scattered to numerous thunderstorms will develop over the mountains
by early afternoon, spreading eastward across the I-25 corridor
during the afternoon and evening hours. From I-25 eastward across
the plains, numerous severe storms are expected, with wind gusts
of 60 to 75 mph, hail from golfball to baseball size and an
increased risk of a few tornadoes under the strongest storms.
Heavy rainfall and flash flooding are also possible, especially
across the southeast plains where heavy rainfall occurred last
night.

To the west of Interstate 25 over the mountains and interior
valleys, lightning and gusty winds of 50 to 60 mph will be the main
storm risks, and a few of the stronger storms may also produce some
small hail and brief heavy rainfall.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Scattered showers and thunderstorms are expected on Friday,
mainly over the eastern mountains and along the I-25 corridor.
Some of these storms may contain hail greater than an inch in
diameter, and wind gusts of 60 mph or greater.

On Saturday, a few thunderstorms will develop during the
afternoon and evening over the higher terrain, and an isolated
thunderstorm or two could move over into the adjacent plains and
over the southern I-25 corridor. There will be a better chance
for afternoon and evening thunderstorms on Sunday over the higher
terrain, with a few storms possibly moving out into the plains.

Thunderstorm activity will begin to ramp back up again beginning
early next week and through the rest of the week over the inner
mountain west, with increasing chances of thunderstorms each day
over the Continental Divide as the monsoonal pattern becomes more
pronounced.

Thunderstorm chances over the plains for next week look to be
more favorable as the week progresses, as there will be increasing
thunderstorm coverage with better westerly flow aloft.

.SPOTTER INFORMATION STATEMENT...

Weather conditions that meet reporting criteria for spotters will
be likely over portions of the region.

RODRIGUEZ

Special Weather Statement
National Weather Service Pueblo CO
224 PM MDT Thu Jul 20 2023

COZ081-084-202100-
Teller County/Rampart Range above 7500fT/Pike's Peak Between 7500 And
11000 Ft CO-
Northern El Paso County/Monument Ridge/Rampart Range Below 7500 Ft
CO-
224 PM MDT Thu Jul 20 2023

...A strong thunderstorm will impact portions of northern Teller and
northwestern El Paso Counties through 300 PM MDT...

At 224 PM MDT, Doppler radar was tracking a strong thunderstorm near
Florissant, or 24 miles northwest of Colorado Springs, moving east at
35 mph.

HAZARD...Wind gusts of 50 to 55 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Woodland Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
central and east central Colorado.

&&

LAT...LON 3897 10528 3903 10529 3910 10491 3895 10489
TIME...MOT...LOC 2024Z 264DEG 31KT 3900 10523

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...55 MPH

Simcoe

Preliminary Local Storm Report
National Weather Service Pueblo CO
227 PM MDT Thu Jul 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0226 PM     Hail             2 NNE Colorado Springs  38.86N 104.81W
07/20/2023  M1.00 inch       El Paso            CO   Trained Spotter

&&

Preliminary Local Storm Report
National Weather Service Pueblo CO
229 PM MDT Thu Jul 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0228 PM     Hail             3 N Colorado Springs    38.87N 104.83W
07/20/2023  M2.50 inch       El Paso            CO   Trained Spotter

&&

Preliminary Local Storm Report
National Weather Service Pueblo CO
230 PM MDT Thu Jul 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0224 PM     Hail             3 NNW Colorado Springs  38.87N 104.84W
07/20/2023  E1.75 inch       El Paso            CO   Public

            Report from mPING: Golf Ball (1.75 in.).

&&

Preliminary Local Storm Report
National Weather Service Pueblo CO
238 PM MDT Thu Jul 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0237 PM     Hail             2 NW Peterson AFB       38.85N 104.73W
07/20/2023  M1.00 inch       El Paso            CO   Trained Spotter

&&

Preliminary Local Storm Report
National Weather Service Pueblo CO
255 PM MDT Thu Jul 20 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0245 PM     Hail             Peterson AFB            38.84N 104.70W
07/20/2023  M1.50 inch       El Paso            CO   Trained Spotter

&&