Alert archive / Texas / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 486

September 17, 20174 states

The Storm Prediction Center issued this severe thunderstorm watch at Sep 17, 2017, 2:41 PM MDT for 4 states. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Sep 17, 2017, 2:41 PM MDT (20:41 UTC)
Expired
Sep 17, 2017, 10:00 PM MDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 61 counties

Baca County, CO, Bent County, CO, Huerfano County, CO, Las Animas County, CO, Otero County, CO, Prowers County, CO, Pueblo County, CO, Chaves County, NM, Colfax County, NM, Curry County, NM, De Baca County, NM, Eddy County, NM, Guadalupe County, NM, Harding County, NM, Lea County, NM, Mora County, NM, Quay County, NM, Roosevelt County, NM, San Miguel County, NM, Union County, NM, Cimarron County, OK, Texas County, OK, Armstrong County, TX, Bailey County, TX, Briscoe County, TX, Carson County, TX, Castro County, TX, Cochran County, TX, Cottle County, TX, Crosby County, TX, Dallam County, TX, Deaf Smith County, TX, Dickens County, TX, Donley County, TX, Floyd County, TX, Gaines County, TX, Garza County, TX, Gray County, TX, Hale County, TX, Hall County, TX, Hansford County, TX, Hartley County, TX, Hockley County, TX, Hutchinson County, TX, Kent County, TX, King County, TX, Lamb County, TX, Lubbock County, TX, Lynn County, TX, Moore County, TX, Motley County, TX, Ochiltree County, TX, Oldham County, TX, Parmer County, TX, Potter County, TX, Randall County, TX, Roberts County, TX, Sherman County, TX, Swisher County, TX, Terry County, TX, Yoakum County, TX

The radar

The Amarillo radar (KAMA), 127 km from the middle of the area, began a volume at 20:43 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
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
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Sep 17, 2:58 PM MDTSevere Thunderstorm WarningABQColfax, Harding, Mora30 min
Sep 17, 2:59 PM MDTSevere Thunderstorm WarningAMADeaf Smith, Oldham, Potter, Randall61 min
Sep 17, 3:07 PM MDTSevere Thunderstorm WarningLUBParmer23 min
Sep 17, 3:22 PM MDTSevere Thunderstorm WarningAMADeaf Smith53 min
Sep 17, 3:32 PM MDTSevere Thunderstorm WarningPUBLas Animas43 min
Sep 17, 3:53 PM MDTSevere Thunderstorm WarningPUBLas Animas37 min
Sep 17, 3:58 PM MDTSevere Thunderstorm WarningLUBHockley, Lamb32 min
Sep 17, 4:08 PM MDTSevere Thunderstorm WarningAMADeaf Smith, Oldham67 min
Sep 17, 4:24 PM MDTSevere Thunderstorm WarningAMAHartley, Moore, Oldham, Potter66 min
Sep 17, 4:26 PM MDTSevere Thunderstorm WarningLUBHale, Hockley, Lamb, Lubbock49 min
Sep 17, 4:42 PM MDTSevere Thunderstorm WarningPUBBaca, Las Animas37 min
Sep 17, 4:46 PM MDTSevere Thunderstorm WarningAMAHartley, Oldham59 min
Sep 17, 5:16 PM MDTSevere Thunderstorm WarningABQQuay14 min
Sep 17, 5:17 PM MDTSevere Thunderstorm WarningAMADeaf Smith, Oldham41 min
Sep 17, 6:17 PM MDTSevere Thunderstorm WarningLUBCrosby, Dickens, Floyd, Motley43 min
Sep 17, 6:50 PM MDTSevere Thunderstorm WarningABQColfax, Union40 min
Sep 17, 7:23 PM MDTSevere Thunderstorm WarningABQUnion52 min
Sep 17, 7:29 PM MDTSevere Thunderstorm WarningABQUnion46 min
Sep 17, 7:58 PM MDTSevere Thunderstorm WarningLUBCottle, Motley62 min
Sep 17, 8:09 PM MDTSevere Thunderstorm WarningABQUnion51 min
Sep 17, 8:20 PM MDTSevere Thunderstorm WarningAMACimarron55 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

Amarillo Airport, TX (KAMA), launched 12:00Z, 8.7 hours before the alert went out and 128 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, Amarillo Airport, TX at 12:00Z on 2017-09-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 240 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Amarillo Airport, TX at 12:00Z on 2017-09-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 137 square meters per square second.19395878Sfc1 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
240 J/kg
Mixed-layer CIN
-249 J/kg
Mixed-layer LCL
1391 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
137 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 17, 4:44 PM MDTMesoscale DiscussionSPCBaca, Bent, Crowley, Las Animas, Otero91 min
Sep 16, 6:32 PM MDTMesoscale DiscussionSPCBrown, Dickinson, Geary, Harvey, Jackson, McPherson and 6 more118 min
Sep 17, 1:28 PM MDTMesoscale DiscussionSPCChaves, Colfax, Curry, De Baca, Guadalupe, Harding and 5 more2 hr
Sep 17, 1:16 PM MDTMesoscale DiscussionSPCAtoka, Beckham, Caddo, Canadian, Carter, Cleveland and 32 more119 min

Nearby

Severe Thunderstorm Watches in Texas, 2017Severe Thunderstorm Watches in New Mexico, 2017Severe Thunderstorm Watches in Colorado, 2017Every severe thunderstorm watch in 2017

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.