Alert archive / Texas / Severe Thunderstorm Watches in 2018

Severe Thunderstorm Watch 101

May 17, 20184 states

The Storm Prediction Center issued this severe thunderstorm watch at May 17, 2018, 2:37 PM MDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 17, 2018, 2:37 PM MDT (20:37 UTC)
Expired
May 17, 2018, 9:00 PM MDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt
All 60 counties

Baca County, CO, Prowers County, CO, Finney County, KS, Grant County, KS, Gray County, KS, Hamilton County, KS, Haskell County, KS, Kearny County, KS, Meade County, KS, Morton County, KS, Seward County, KS, Stanton County, KS, Stevens County, KS, Beaver County, OK, Cimarron County, OK, Texas County, OK, Armstrong County, TX, Bailey County, TX, Briscoe County, TX, Carson County, TX, Castro County, TX, Childress County, TX, Cochran County, TX, Collingsworth County, TX, Cottle County, TX, Crosby County, TX, Dallam County, TX, Deaf Smith County, TX, Dickens County, TX, Donley County, TX, Floyd County, TX, Garza County, TX, Gray County, TX, Hale County, TX, Hall County, TX, Hansford County, TX, Hartley County, TX, Hemphill County, TX, Hockley County, TX, Hutchinson County, TX, Kent County, TX, King County, TX, Lamb County, TX, Lipscomb 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, Stonewall County, TX, Swisher County, TX, Terry County, TX, Wheeler County, TX, Yoakum County, TX

The radar

The Amarillo radar (KAMA), 90 km from the middle of the area, began a volume at 20:38 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
60%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 17, 2:43 PM MDTSevere Thunderstorm WarningLUBHockley, Lamb40 min
May 17, 2:53 PM MDTSevere Thunderstorm WarningLUBCastro, Parmer52 min
May 17, 3:14 PM MDTSevere Thunderstorm WarningLUBHockley, Lubbock46 min
May 17, 3:26 PM MDTSevere Thunderstorm WarningAMADeaf Smith, Oldham, Randall45 min
May 17, 3:35 PM MDTSevere Thunderstorm WarningLUBCastro, Hale, Lamb, Swisher55 min
May 17, 3:41 PM MDTSevere Thunderstorm WarningLUBBriscoe, Floyd, Hale, Swisher64 min
May 17, 4:09 PM MDTSevere Thunderstorm WarningAMAHutchinson, Moore66 min
May 17, 4:12 PM MDTSevere Thunderstorm WarningLUBTerry, Yoakum48 min
May 17, 4:21 PM MDTSevere Thunderstorm WarningAMATexas54 min
May 17, 4:21 PM MDTSevere Thunderstorm WarningLUBCrosby, Garza, Lubbock, Lynn39 min
May 17, 4:29 PM MDTSevere Thunderstorm WarningLUBBriscoe, Floyd, Hale, Swisher61 min
May 17, 4:31 PM MDTSevere Thunderstorm WarningAMAMoore59 min
May 17, 4:32 PM MDTSevere Thunderstorm WarningLUBBriscoe, Cottle, Floyd, Hall, Motley58 min
May 17, 4:33 PM MDTSevere Thunderstorm WarningDDCMorton, Stevens57 min
May 17, 4:59 PM MDTSevere Thunderstorm WarningAMAHartley, Hutchinson, Moore46 min
May 17, 5:00 PM MDTSevere Thunderstorm WarningLUBGarza60 min
May 17, 5:26 PM MDTSevere Thunderstorm WarningLUBBriscoe, Childress, Cottle, Hall, Motley64 min
May 17, 5:39 PM MDTSevere Thunderstorm WarningAMACollingsworth, Donley, Wheeler38 min
May 17, 5:46 PM MDTSevere Thunderstorm WarningAMAHutchinson, Moore74 min
May 17, 5:50 PM MDTSevere Thunderstorm WarningAMATexas50 min
May 17, 5:53 PM MDTSevere Thunderstorm WarningLUBGarza, Kent39 min
May 17, 5:57 PM MDTTornado WarningLUBGarza, Kent33 min
May 17, 6:27 PM MDTSevere Thunderstorm WarningLUBChildress, Cottle, Hall, Motley63 min
May 17, 6:30 PM MDTSevere Thunderstorm WarningLUBGarza, Kent60 min
May 17, 7:01 PM MDTSevere Thunderstorm WarningAMAHutchinson, Roberts59 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, 8.6 hours before the alert went out and 90 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 2018-05-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 784 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 2018-05-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 246 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
784 J/kg
Mixed-layer CIN
-326 J/kg
Mixed-layer LCL
1460 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
246 m²/s²
0-3 km storm-relative helicity
294 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 17, 1:38 PM MDTMesoscale DiscussionSPCBaca, Prowers2 hr
May 17, 4:19 PM MDTMesoscale DiscussionSPCAdams, Arapahoe, Logan, Morgan, Phillips, Sedgwick and 3 more116 min
May 17, 4:57 PM MDTSevere Thunderstorm WatchSPCLogan, Phillips, Sedgwick6 hr
May 17, 9:32 AM MDTMesoscale DiscussionSPCClark, Comanche, Ford, Gray, Haskell, Hodgeman and 2 more2 hr
May 17, 5:44 PM MDTMesoscale DiscussionSPCBeckham, Greer, Harmon, Jackson, Roger Mills61 min
May 17, 3:39 PM MDTMesoscale DiscussionSPCAndrews, Borden, Crane, Crockett, Dawson, Ector and 10 more66 min

Nearby

Severe Thunderstorm Watches in Texas, 2018Severe Thunderstorm Watches in Kansas, 2018Severe Thunderstorm Watches in Oklahoma, 2018Every severe thunderstorm watch in 2018

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.