Alert archive / Oklahoma / Mesoscale Discussions in 2011

Mesoscale Discussion 1940

August 11, 2011Harper County, Kansas; 17 counties in Oklahoma; 13 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Aug 11, 2011, 3:15 AM CDT for Harper County, Kansas; 17 counties in Oklahoma; 13 counties in Texas. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
Aug 11, 2011, 3:15 AM CDT (08:15 UTC)
Expired
Aug 11, 2011, 4:45 AM CDT
In force
90 min
Issued by
the Storm Prediction Center
All 31 counties

Harper County, KS, Alfalfa County, OK, Beaver County, OK, Beckham County, OK, Blaine County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Grant County, OK, Harper County, OK, Kingfisher County, OK, Major County, OK, Roger Mills County, OK, Texas County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Carson County, TX, Gray County, TX, Hansford County, TX, Hartley County, TX, Hemphill County, TX, Hutchinson County, TX, Lipscomb County, TX, Moore County, TX, Ochiltree County, TX, Potter County, TX, Roberts County, TX, Sherman County, TX, Wheeler County, TX

The radar

The Amarillo radar (KAMA), 138 km from the middle of the area, began a volume at 08:19 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.

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 00:00Z, 8.3 hours before the alert went out and 137 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 00:00Z on 2011-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1689 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 00:00Z on 2011-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
1689 J/kg
Mixed-layer CIN
-88 J/kg
Mixed-layer LCL
2170 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
246 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 10, 7:50 PM CDTSevere Thunderstorm WatchSPCCheyenne, Decatur, Gove, Logan, Rawlins, Sheridan and 3 more3 hr
Aug 10, 10:10 PM CDTMesoscale DiscussionSPCCheyenne, Decatur, Logan, Rawlins, Sheridan, Sherman and 1 more95 min
Aug 10, 7:23 PM CDTMesoscale DiscussionSPCAdair, Cherokee, Creek, Haskell, Hughes, Latimer and 12 more97 min
Aug 11, 2:13 PM CDTMesoscale DiscussionSPCChoctaw, McCurtain62 min
Aug 11, 5:06 PM CDTMesoscale DiscussionSPCArmstrong, Bailey, Briscoe, Castro, Cochran, Crosby and 15 more84 min

Nearby

Mesoscale Discussions in Oklahoma, 2011Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Kansas, 2011Every mesoscale discussion in 2011

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.