Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 930

May 27, 2012Terrell County, Texas

The Storm Prediction Center issued this mesoscale discussion at May 27, 2012, 7:37 PM CDT for Terrell County, Texas. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
May 27, 2012, 7:37 PM CDT (00:37 UTC)
Expired
May 27, 2012, 8:30 PM CDT
In force
53 min
Issued by
the Storm Prediction Center
Chance of a watch
5%

County Terrell County, TX

The radar

The Midland/Odessa radar (KMAF), 184 km from the middle of the area, began a volume at 00:37 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

Del Rio, TX (KDRT), launched 00:00Z, 0.6 hours before the alert went out and 171 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, Del Rio, TX at 00:00Z on 2012-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1285 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, Del Rio, TX at 00:00Z on 2012-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 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
1285 J/kg
Mixed-layer CIN
-103 J/kg
Mixed-layer LCL
1535 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
153 m²/s²
Significant tornado parameter
0.4
Supercell composite
4.0

Open this sounding in Storm Lab

The text

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

478 
ACUS11 KWNS 280038
SWOMCD
SPC MCD 280037
TXZ000-280130-

MESOSCALE DISCUSSION 0930
NWS STORM PREDICTION CENTER NORMAN OK
0737 PM CDT SUN MAY 27 2012

AREAS AFFECTED...SWRN TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 280037Z - 280130Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...THREAT FOR VERY LARGE HAIL AND A TORNADO EXPECTED TO
PERSIST UNTIL AROUND 0130Z WITH STORM OVER SWRN TX BETWEEN FORT
STOCKTON AND SANDERSON. ON IT PRESENT COURSE THE STORM MAY AFFECT
THE TOWN OF SANDERSON BY 01Z. DUE TO THE LIMITED DURATION AND AREAL
EXTENT OF THE SEVERE THREAT...A WW IS NOT ANTICIPATED.

DISCUSSION...ISOLATED SUPERCELL STORM THAT DEVELOPED OVER THE HIGHER
TERRAIN OF SWRN TX IS LOCATED ABOUT 25 SM NW OF SANDERSON TX MOVING
SEWD. THE ENVIRONMENT WITHIN WHICH THIS STORM IS DEVELOPING IS
CHARACTERIZED BY 2500 J/KG MLCAPE...50 KT EFFECTIVE SHEAR AND
SUFFICIENT 0-1 KM SHEAR FOR LOW LEVEL MESOCYCLONES. RECENT RADAR
TRENDS HAVE BEEN FOR THIS STORM TO DECREASE IN SIZE AND INTENSITY.
INCREASING CONVECTIVE INHIBITION ASSOCIATED WITH ONSET OF NOCTURNAL
COOLING WILL PROBABLY RESULT IN A CONTINUED GRADUAL DECREASE AND
EVENTUAL DISSIPATION. IN THE MEANTIME...THE STORM WILL REMAIN
CAPABLE OF VERY LARGE HAIL AND A TORNADO THROUGH ABOUT 01-0130Z.

..DIAL/HART.. 05/28/2012

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

ATTN...WFO...EWX...MAF...

LAT...LON   30620220 29960167 29840256 30430266 30620220

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 28, 2:54 PM CDTMesoscale DiscussionSPCAndrews, Archer, Baylor, Borden, Cottle, Crane and 30 more96 min
May 28, 3:48 PM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Borden, Brown, Callahan, Clay and 47 more8 hr
May 28, 6:14 PM CDTMesoscale DiscussionSPCArcher, Baylor, Borden, Clay, Dawson, Dickens and 23 more91 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.