Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 757

May 8, 201217 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 8, 2012, 10:44 AM CDT for 17 counties in Texas. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued
May 8, 2012, 10:44 AM CDT (15:44 UTC)
Expired
May 8, 2012, 11:45 AM CDT
In force
61 min
Issued by
the Storm Prediction Center
Chance of a watch
80%

Counties Bee County, TX, Brooks County, TX, Duval County, TX, Frio County, TX, Goliad County, TX, Jim Hogg County, TX, Jim Wells County, TX, Kleberg County, TX, La Salle County, TX, Live Oak County, TX, McMullen County, TX, Nueces County, TX, Refugio County, TX, San Patricio County, TX, Starr County, TX, Webb County, TX, Zapata County, TX

The radar

The Corpus Christi radar (KCRP), 124 km from the middle of the area, began a volume at 15:44 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

Corpus Christi, TX (KCRP), launched 12:00Z, 3.7 hours before the alert went out and 141 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 12:00Z on 2012-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2526 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 12:00Z on 2012-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -53 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
2526 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
573 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
-53 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
-1.1
Supercell composite
-5.1

Open this sounding in Storm Lab

The text

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

644 
ACUS11 KWNS 081545
SWOMCD
SPC MCD 081544
TXZ000-081645-

MESOSCALE DISCUSSION 0757
NWS STORM PREDICTION CENTER NORMAN OK
1044 AM CDT TUE MAY 08 2012

AREAS AFFECTED...DEEP SOUTH TEXAS

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 081544Z - 081645Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...SHORT TERM CONVECTIVE TRENDS REMAIN UNCERTAIN...BUT
CURRENT INTENSIFICATION OF A STORM TO THE SOUTH OF LAREDO MAY
REQUIRE A WATCH SHORTLY.

DISCUSSION...WITHIN AN AREA LARGE-SCALE ASCENT DOWNSTREAM OF THE
SOUTHWESTERN U.S. CLOSED LOW AND UPPER TROUGH EXTENDING SOUTHWARD
THROUGH BAJA...SCATTERED THUNDERSTORM ACTIVITY CONTINUES TO
GRADUALLY SPREAD EASTWARD THROUGH THE LOWER RIO GRANDE VALLEY TOWARD
LOWER TEXAS COASTAL AREAS.  ACTIVITY EAST OF THE RIVER HAS BEEN
GENERALLY CONFINED TO THE COOL SIDE OF A SOUTHWARD ADVANCING COLD
FRONT...WITH RESIDUAL WARMER ELEVATED MIXED LAYER AIR STILL
INHIBITIVE OF BOUNDARY LAYER BASED STORM DEVELOPMENT TO THE SOUTH.
ADDITIONALLY...LATEST RAPID REFRESH IS SUGGESTIVE THAT LOWER/MID
TROPOSPHERIC WARM ADVECTION MAY WEAKEN ACROSS THE REGION DURING THE
17-19Z...WHICH COULD RESULT IN DIMINISHING CONVECTIVE TRENDS.
SO...NEAR TERM SEVERE WEATHER POTENTIAL REMAINS UNCLEAR.

HOWEVER...RECENT INTENSIFICATION OF A CELL IS UNDERWAY OFF THE
HIGHER TERRAIN TO THE SOUTHWEST OF LAREDO.  THIS APPEARS TO THE
SOUTH OF THE FRONT...AND WEAK WESTERLY DEEP LAYER MEAN FLOW COULD
AID PROPAGATION INTO A DESTABILIZING ENVIRONMENT EAST OF THE
RIVER...WHERE ADDITIONAL SURFACE HEATING COULD CONTRIBUTE TO
WEAKENING OF INHIBITION AND FURTHER INTENSIFICATION.

..KERR.. 05/08/2012

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

ATTN...WFO...CRP...EWX...BRO...

LAT...LON   28050007 28889910 28879808 28719713 27899710 27019753
            26419815 26589924 26939993 27700012 28050007

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 7, 7:39 PM CDTSevere Thunderstorm WatchSPCCamp, Gregg, Harrison, Marion, Morris, Panola and 5 more4 hr
May 7, 7:54 PM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bee, Bexar, Brazos and 40 more66 min
May 7, 9:15 PM CDTMesoscale DiscussionSPCCamp, Cass, Gregg, Harrison, Marion, Morris and 6 more60 min
May 7, 9:46 PM CDTMesoscale DiscussionSPCAndrews, Borden, Crane, Crockett, Dawson, Ector and 15 more89 min
May 8, 1:42 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bexar, Comal, Dimmit, Edwards and 13 more93 min
May 8, 10:58 AM CDTSevere Thunderstorm WatchSPCAransas, Atascosa, Bee, Brooks, Calhoun, Cameron and 28 more8 hr
May 8, 1:37 PM CDTMesoscale DiscussionSPCBrewster, Culberson, El Paso, Hudspeth, Jeff Davis, Presidio and 1 more113 min
May 8, 2:07 PM CDTSevere Thunderstorm WatchSPCBrewster, Culberson, El Paso, Hudspeth, Jeff Davis, Presidio7 hr
May 8, 3:03 PM CDTMesoscale DiscussionSPCCameron, Hidalgo, Starr, Willacy87 min
May 8, 4:53 PM CDTMesoscale DiscussionSPCBrewster, Culberson, El Paso, Hudspeth, Jeff Davis, Presidio67 min
May 8, 5:47 PM CDTMesoscale DiscussionSPCCameron, Hidalgo, Kenedy, Willacy58 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.