Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 782

May 10, 201242 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 10, 2012, 9:42 PM CDT for 42 counties in Texas. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
May 10, 2012, 9:42 PM CDT (02:42 UTC)
Expired
May 10, 2012, 10:45 PM CDT
In force
63 min
Issued by
the Storm Prediction Center
All 42 counties

Aransas County, TX, Atascosa County, TX, Austin County, TX, Bastrop County, TX, Bee County, TX, Bell County, TX, Bexar County, TX, Brooks County, TX, Burleson County, TX, Caldwell County, TX, Calhoun County, TX, Colorado County, TX, Comal County, TX, DeWitt County, TX, Duval County, TX, Fayette County, TX, Goliad County, TX, Gonzales County, TX, Guadalupe County, TX, Hays County, TX, Jackson County, TX, Jim Hogg County, TX, Jim Wells County, TX, Karnes County, TX, Kenedy County, TX, Kleberg County, TX, Lavaca County, TX, Lee County, TX, Live Oak County, TX, Matagorda County, TX, McMullen County, TX, Milam County, TX, Nueces County, TX, Refugio County, TX, San Patricio County, TX, Travis County, TX, Victoria County, TX, Washington County, TX, Wharton County, TX, Williamson County, TX, Wilson County, TX, Zapata County, TX

The radar

The Corpus Christi radar (KCRP), 99 km from the middle of the area, began a volume at 02:45 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

Corpus Christi, TX (KCRP), launched 00:00Z, 2.7 hours before the alert went out and 107 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, Corpus Christi, TX at 00:00Z on 2012-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2214 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, Corpus Christi, TX at 00:00Z on 2012-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 204 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
2214 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
636 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
204 m²/s²
0-3 km storm-relative helicity
274 m²/s²
Significant tornado parameter
3.4
Supercell composite
14.5

Open this sounding in Storm Lab

The text

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

092 
ACUS11 KWNS 110242
SWOMCD
SPC MCD 110242 
TXZ000-110345-

MESOSCALE DISCUSSION 0782
NWS STORM PREDICTION CENTER NORMAN OK
0942 PM CDT THU MAY 10 2012

AREAS AFFECTED...S-CNTRL/DEEP SOUTH TX

CONCERNING...TORNADO WATCH 273...

VALID 110242Z - 110345Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 273 CONTINUES.

SUMMARY...THE SVR THREAT CONTINUES ACROSS WW273. THE MAIN THREAT IS
EVOLVING TOWARD DMGG WINDS...THOUGH LARGE HAIL AND PERHAPS A TORNADO
OR TWO WILL REMAIN POSSIBLE.

DISCUSSION...SFC MESOANALYSIS AT 02Z INDICATES THAT AN OUTFLOW
BOUNDARY CURRENTLY EXTENDS FROM THE TX/MEXICO BORDER SOUTH OF LAREDO
TO NEAR VICTORIA TO THE PALACIOS AREA. THE WRN EXTENT OF THE
BOUNDARY IS BEGINNING TO EXHIBIT SWD MOTION. THIS WILL CONTINUE AS
COLD POOLS ELONGATE ALONG THE BOUNDARY FROM WEBB TO SAN PATRICIO
COUNTIES AND CONVECTION PROPAGATES ESEWD INTO THE STRONGLY UNSTABLE
AIR MASS OVER PARTS OF DEEP SOUTH TX -- E.G. MLCAPE VALUES OF
2000-3000 J/KG PER CORPUS CHRISTI AND BROWNSVILLE 00Z RAOBS. THIS
WILL SUPPORT A THREAT FOR SVR WINDS INTO THE SRN PARTS OF THE WW
AREA WITH BOWING LINE SEGMENTS...WHILE EMBEDDED SUPERCELL STRUCTURES
MAY SUPPORT A THREAT FOR SVR HAIL AND PERHAPS A TORNADO OR TWO GIVEN
250 M2/S2 OF 0-1-KM SRH PER CORPUS CHRISTI VWP DATA. THIS THREAT
WILL LIKELY EXTEND TOWARD THE LOWER/MIDDLE TX COAST WITH
TIME...WHERE CONTINUED DESTABILIZATION IS SUPPORTED BY THE LOW-LEVEL
WAA REGIME IN PLACE AMIDST APPRECIABLE LOW-LEVEL AND DEEP-LAYER
SHEAR.

FARTHER NORTH ACROSS THE WW AREA...A WIND-SHIFT AXIS EXTENDS FROM 15
MILES ESE OF LAREDO NNEWD TO 35 MILES WSW OF TEMPLE. THE POSITION OF
THIS FEATURE IS BEING MODIFIED BY A QLCS ACROSS NRN SECTIONS OF THE
WW AREA. DEEP MERIDIONAL FLOW PER FORT HOOD VWP DATA SHOULD PROVIDE
AMPLE LOW-LEVEL MOISTURE TRANSPORT AND WAA AHEAD OF THE
QLCS...YIELDING MODEST DESTABILIZATION OF THE LEADING AIR MASS. THIS
COULD SUPPORT THE POTENTIAL FOR CONTINUED FORWARD-PROPAGATION DURING
THE NEXT FEW HOURS. DMGG WIND GUSTS AND PERHAPS A WEAK/BRIEF TORNADO
WILL BE THE MAIN CONCERNS WITH THIS ACTIVITY...PARTICULARLY IF THE
NEAR-SFC LAYER CAN MODIFY/DESTABILIZE WITH TIME. THE WIND SHIFT AXIS
WILL DENOTE THE WRN EXTENT OF THE SVR THREAT.

..COHEN.. 05/11/2012

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

ATTN...WFO...HGX...FWD...CRP...EWX...BRO...

LAT...LON   29409585 28759588 27989676 27339725 26689759 26669848
            26789947 27319958 28309903 30259835 31099770 31079707
            30499634 29409585

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 10, 7:18 PM CDTMesoscale DiscussionSPCAransas, Atascosa, Austin, Bastrop, Bee, Bexar and 43 more57 min
May 10, 7:50 PM CDTTornado WatchSPCAransas, Atascosa, Austin, Bastrop, Bee, Bell and 48 more9 hr
May 10, 11:36 PM CDTMesoscale DiscussionSPCAransas, Brooks, Calhoun, Cameron, Hidalgo, Jackson and 13 more84 min
May 11, 1:40 AM CDTMesoscale DiscussionSPCAransas, Austin, Bee, Brazoria, Brooks, Calhoun and 25 more65 min
May 11, 2:41 AM CDTMesoscale DiscussionSPCCameron, Chambers, Galveston, Hidalgo, Jefferson, Kenedy and 3 more34 min
May 11, 1:22 PM CDTMesoscale DiscussionSPCAnderson, Bosque, Camp, Cherokee, Collin, Cooke and 28 more53 min
May 11, 2:13 PM CDTMesoscale DiscussionSPCAtascosa, Austin, Bandera, Bastrop, Bell, Bexar and 41 more2 hr
May 11, 5:18 PM CDTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bastrop, Bell, Blanco and 40 more87 min
May 11, 5:51 PM CDTMesoscale DiscussionSPCBee, Brooks, Duval, Goliad, Hidalgo, Jim Hogg and 7 more84 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.