Alert archive / Colorado / Tornado Watches in 2021

Tornado Watch 175

May 15, 20216 counties in Colorado; 6 counties in Kansas

The Storm Prediction Center issued this tornado watch at May 15, 2021, 5:07 PM MDT for 6 counties in Colorado; 6 counties in Kansas. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 15, 2021, 5:07 PM MDT (23:07 UTC)
Expired
May 15, 2021, 10:00 PM MDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt

Counties Baca County, CO, Bent County, CO, Crowley County, CO, Kiowa County, CO, Otero County, CO, Prowers County, CO, Grant County, KS, Hamilton County, KS, Kearny County, KS, Morton County, KS, Stanton County, KS, Stevens County, KS

The radar

The Pueblo radar (KPUX), 145 km from the middle of the area, began a volume at 23:06 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
30%
One or more EF2 to EF5 tornadoes
10%
Ten or more severe wind reports
20%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

9 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 15, 5:22 PM MDTSevere Thunderstorm WarningPUBBaca38 min
May 15, 5:46 PM MDTSevere Thunderstorm WarningPUBBent, Otero59 min
May 15, 6:22 PM MDTSevere Thunderstorm WarningPUBBaca23 min
May 15, 6:26 PM MDTSevere Thunderstorm WarningPUBBent, Crowley, Kiowa, Otero64 min
May 15, 6:56 PM MDTSevere Thunderstorm WarningPUBProwers64 min
May 15, 6:58 PM MDTSevere Thunderstorm WarningPUBBaca32 min
May 15, 7:01 PM MDTTornado WarningPUBBent17 min
May 15, 8:30 PM MDTSevere Thunderstorm WarningPUBKiowa45 min
May 15, 9:07 PM MDTSevere Thunderstorm WarningDDCStevens38 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 11.1 hours before the alert went out and 232 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2021-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 21 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2021-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
21 J/kg
Mixed-layer CIN
-326 J/kg
Mixed-layer LCL
769 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

543 
WWUS20 KWNS 152303
SEL5  
SPC WW 152303
COZ000-KSZ000-160400-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 175
NWS Storm Prediction Center Norman OK
505 PM MDT Sat May 15 2021

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Southeast Colorado
  Southwest Kansas

* Effective this Saturday afternoon and evening from 505 PM until
  1000 PM MDT.

* Primary threats include...
  A couple tornadoes possible
  Isolated very large hail events to 2.5 inches in diameter
    possible
  Isolated damaging wind gusts to 70 mph possible

SUMMARY...A supercell or two may develop along an west-northwest to
east-southeast oriented boundary with a risk for a couple tornadoes.

The tornado watch area is approximately along and 40 statute miles
north and south of a line from 25 miles south southwest of La Junta
CO to 80 miles east northeast of Springfield CO. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU5).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 172...WW 173...WW 174...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean
storm motion vector 29020.

...Grams

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 15, 1:57 PM MDTMesoscale DiscussionSPCAdams, Arapahoe, Baca, Bent, Cheyenne, Crowley and 15 more2 hr
May 15, 4:06 PM MDTSevere Thunderstorm WatchSPCBaca, Bent, Cheyenne, Crowley, Douglas, Elbert and 9 more6 hr
May 15, 5:17 PM MDTMesoscale DiscussionSPCBent, Prowers58 min
May 14, 6:10 PM MDTMesoscale DiscussionSPCEllis, Gove, Graham, Lane, Logan, Ness and 5 more2 hr
May 14, 6:27 PM MDTSevere Thunderstorm WatchSPCBarber, Barton, Comanche, Edwards, Ellis, Ellsworth and 16 more5 hr
May 14, 8:42 PM MDTMesoscale DiscussionSPCEdwards, Hodgeman, Ness, Pawnee63 min
May 15, 5:44 PM MDTMesoscale DiscussionSPCChautauqua, Cowley, Edwards, Ford, Hodgeman, Kingman and 7 more61 min
May 15, 5:53 PM MDTSevere Thunderstorm WatchSPCBarber, Barton, Clark, Comanche, Edwards, Ellis and 37 more6 hr

Nearby

Tornado Watches in Colorado, 2021Tornado Watches in Kansas, 2021Every tornado watch in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.