Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 863

May 21, 20129 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 21, 2012, 9:33 PM CDT for 9 counties in Texas. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
May 21, 2012, 9:33 PM CDT (02:33 UTC)
Expired
May 21, 2012, 11:00 PM CDT
In force
87 min
Issued by
the Storm Prediction Center

Counties Bailey County, TX, Castro County, TX, Cochran County, TX, Hale County, TX, Hockley County, TX, Lamb County, TX, Parmer County, TX, Randall County, TX, Swisher County, TX

The radar

The Lubbock radar (KLBB), 99 km from the middle of the area, began a volume at 02:34 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, 2.6 hours before the alert went out and 123 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 2012-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 118 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 2012-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 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
118 J/kg
Mixed-layer CIN
-79 J/kg
Mixed-layer LCL
2075 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
231 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

960 
ACUS11 KWNS 220233
SWOMCD
SPC MCD 220233 
TXZ000-NMZ000-220400-

MESOSCALE DISCUSSION 0863
NWS STORM PREDICTION CENTER NORMAN OK
0933 PM CDT MON MAY 21 2012

AREAS AFFECTED...PARTS OF E CNTRL NEW MEXICO AND THE WRN TEXAS
PANHANDLE

CONCERNING...SEVERE THUNDERSTORM WATCH 287...

VALID 220233Z - 220400Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 287
CONTINUES.

SUMMARY...IT STILL APPEARS THAT A NEW WW WILL NOT BE NEEDED...BUT IT
IS NOT OUT OF THE QUESTION THAT AN HOUR OR SO LOCAL EXTENSION IN
TIME MAY BECOME NECESSARY...PERHAPS WITH AN ADDITIONAL ROW OR TWO OF
COUNTIES ADDED TO THE WATCH...BOTH EAST SOUTHEAST OF AMARILLO ...AND
PERHAPS INCLUDING THE LUBBOCK AREA.

DISCUSSION...VIGOROUS CONVECTIVE DEVELOPMENT PERSISTS ON THE LEADING
EDGE OF THE SIGNIFICANT CONSOLIDATED COLD POOL NOW SPREADING INTO
THE TEXAS PANHANDLE...WEST/SOUTHWEST OF AMARILLO.  THE COLD POOL MAY
TEND TO SURGE MORE SOUTH THAN EAST BETWEEN NOW AND 03-04Z...BUT
COULD STILL IMPACT THE AMARILLO AREA.  SOUTH SOUTHEASTERLY NEAR
SURFACE SYSTEM RELATIVE INFLOW IS RATHER MODEST...AND INGESTION OF
MORE STABLE AIR STILL SEEMS LIKELY TO BEGIN TO WEAKEN ACTIVITY AND
DIMINISH THE SEVERE POTENTIAL WITHIN THE NEXT COUPLE OF HOURS.

..KERR.. 05/22/2012

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

ATTN...WFO...LUB...AMA...MAF...ABQ...

LAT...LON   34370340 34690253 35370196 34760109 33500207 33300308
            34370340

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 21, 7:40 PM CDTMesoscale DiscussionSPCBailey, Castro, Deaf Smith, Hartley, Lamb, Oldham and 3 more95 min
May 22, 2:06 PM CDTMesoscale DiscussionSPCDallam, Hansford, Hartley, Hutchinson, Moore, Ochiltree and 3 more84 min
May 22, 5:10 PM CDTMesoscale DiscussionSPCBrewster65 min

Nearby

Mesoscale Discussions in Texas, 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.