Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 481

April 9, 20128 counties in Oklahoma; 28 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2012, 5:37 PM CDT for 8 counties in Oklahoma; 28 counties in Texas. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
Apr 9, 2012, 5:37 PM CDT (22:37 UTC)
Expired
Apr 9, 2012, 7:00 PM CDT
In force
83 min
Issued by
the Storm Prediction Center
All 36 counties

Beckham County, OK, Custer County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kiowa County, OK, Roger Mills County, OK, Washita County, OK, Armstrong 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, Dickens County, TX, Donley County, TX, Floyd County, TX, Foard County, TX, Gray County, TX, Hale County, TX, Hall County, TX, Hardeman County, TX, Hemphill County, TX, Hockley County, TX, King County, TX, Knox County, TX, Lamb County, TX, Lubbock County, TX, Motley County, TX, Randall County, TX, Swisher County, TX, Wheeler County, TX, Wilbarger County, TX

The radar

The Amarillo radar (KAMA), 107 km from the middle of the area, began a volume at 22:40 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 12:00Z, 10.6 hours before the alert went out and 106 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 2012-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 505 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 2012-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 square meters per square second.1939587897Sfc1 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
505 J/kg
Mixed-layer CIN
-170 J/kg
Mixed-layer LCL
1025 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

663 
ACUS11 KWNS 092238
SWOMCD
SPC MCD 092237
OKZ000-TXZ000-NMZ000-100000-

MESOSCALE DISCUSSION 0481
NWS STORM PREDICTION CENTER NORMAN OK
0537 PM CDT MON APR 09 2012

AREAS AFFECTED...NWRN TX...SWRN OK

CONCERNING...SEVERE THUNDERSTORM WATCH 152...

VALID 092237Z - 100000Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 152
CONTINUES.

MULTIPLE THUNDERSTORM UPDRAFTS ARE BEGINNING TO MERGE ACROSS THE ERN
TX PANHANDLE AND AN MCS SHOULD EVOLVE OVER THE NEXT FEW HOURS.
LATEST RADAR DATA SUGGESTS INDIVIDUAL STORM CELLS ARE MOVING SEWD AT
ROUGHLY 15KT BUT OVERALL SPEED MAY GRADUALLY INCREASE AS MCS MATURES
AND PRECIP OUTFLOW BECOMES MORE ORGANIZED.  GIVEN THESE TRENDS IT
WOULD APPEAR LIKELY THAT A SLOW MOVING COMPLEX OF STORMS WILL SPREAD
ACROSS SWRN OK BETWEEN 00-03Z.  LARGE HAIL CAN BE EXPECTED WITH THE
STRONGEST UPDRAFTS.

..DARROW.. 04/09/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...OUN...LUB...AMA...MAF...

LAT...LON   33490306 35830162 35839804 33499959 33490306

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 9, 1:54 PM CDTMesoscale DiscussionSPCAlfalfa, Beaver, Blaine, Custer, Dewey, Ellis and 7 more96 min
Apr 9, 2:28 PM CDTTornado WatchSPCAlfalfa, Blaine, Dewey, Ellis, Harper, Major and 2 more5 hr
Apr 9, 3:06 PM CDTMesoscale DiscussionSPCBeckham, Greer, Harmon, Jackson, Kiowa, Roger Mills and 1 more54 min
Apr 9, 3:23 PM CDTSevere Thunderstorm WatchSPCBeckham, Caddo, Comanche, Custer, Greer, Harmon and 5 more8 hr
Apr 9, 6:27 PM CDTTornado WatchSPCBeckham, Blaine, Caddo, Comanche, Cotton, Custer and 11 more8 hr
Apr 9, 5:03 PM CDTMesoscale DiscussionSPCAndrews, Crane, Dawson, Ector, Gaines, Jeff Davis and 9 more87 min
Apr 9, 5:32 PM CDTSevere Thunderstorm WatchSPCAndrews, Brewster, Crane, Crockett, Culberson, Dawson and 18 more7 hr

Nearby

Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Oklahoma, 2012Every mesoscale discussion in 2012

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.