Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 774

May 10, 201230 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 10, 2012, 11:52 AM CDT for 30 counties in Texas. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
May 10, 2012, 11:52 AM CDT (16:52 UTC)
Expired
May 10, 2012, 12:45 PM CDT
In force
53 min
Issued by
the Storm Prediction Center
All 30 counties

Bandera County, TX, Bexar County, TX, Blanco County, TX, Brown County, TX, Coke County, TX, Coleman County, TX, Comal County, TX, Concho County, TX, Edwards County, TX, Gillespie County, TX, Irion County, TX, Kendall County, TX, Kerr County, TX, Kimble County, TX, Kinney County, TX, Llano County, TX, Mason County, TX, McCulloch County, TX, Medina County, TX, Menard County, TX, Nolan County, TX, Real County, TX, Runnels County, TX, San Saba County, TX, Schleicher County, TX, Sterling County, TX, Sutton County, TX, Tom Green County, TX, Uvalde County, TX, Val Verde County, TX

The watches that followed

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

The nearest sounding before it

Del Rio, TX (KDRT), launched 12:00Z, 4.9 hours before the alert went out and 153 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 12:00Z on 2012-05-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1149 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 12:00Z on 2012-05-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 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
1149 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
663 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
185 m²/s²
Significant tornado parameter
1.7
Supercell composite
7.4

Open this sounding in Storm Lab

The text

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

804 
ACUS11 KWNS 101652
SWOMCD
SPC MCD 101652 
TXZ000-101745-

MESOSCALE DISCUSSION 0774
NWS STORM PREDICTION CENTER NORMAN OK
1152 AM CDT THU MAY 10 2012

AREAS AFFECTED...MIDDLE RIO GRANDE VALLEY INTO PARTS OF CENTRAL TX

CONCERNING...SEVERE THUNDERSTORM WATCH 270...

VALID 101652Z - 101745Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 270
CONTINUES.

SUMMARY...SEVERE THREAT CONTINUES FROM THE MIDDLE RIO GRANDE VALLEY
EWD INTO PARTS OF CENTRAL TX.  NEW WW WILL LIKELY BE NEEDED AS
REMAINING PORTIONS OF WW 270 ARE SET TO EXPIRE AT 10/18Z.

DISCUSSION...THE EWD-MOVING UPPER LOW CONTINUES TO APPROACH FAR W TX
PER THE LATEST WV SATELLITE LOOP...WITH STORMS ONGOING ACROSS PARTS
OF CENTRAL AND S TX AHEAD OF THIS FEATURE.  WHILE THE MOST FAVORABLE
THERMODYNAMIC ENVIRONMENT EXISTS ACROSS S TX -- WHERE NEWLY ISSUED
TORNADO WATCH 271 RESIDES...THE ENVIRONMENT FARTHER N ACROSS THE
REMAINING PORTION OF WW 270 REMAINS SUGGESTIVE OF DAMAGING WIND/HAIL
POTENTIAL.  WITH THE BACKGROUND ENVIRONMENT SUPPORTING PERSISTENT
CONVECTIVE ACTIVITY...CONTINUATION OF THE ONGOING SEVERE POTENTIAL
WARRANTS NEW WW ISSUANCE ACROSS THIS REGION.

..GOSS/MEAD.. 05/10/2012

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

ATTN...WFO...FWD...EWX...SJT...MAF...

LAT...LON   29019937 29050069 29910130 30700095 32120118 32410019
            31819874 30609821 29579816 29019937

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 9, 10:09 PM CDTMesoscale DiscussionSPCHidalgo, Kenedy, Willacy66 min
May 10, 5:27 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Brooks, Dimmit, Duval, Edwards and 19 more2 hr
May 10, 5:42 AM CDTSevere Thunderstorm WatchSPCAtascosa, Bandera, Bee, Bexar, Brooks, Cameron and 36 more7 hr
May 10, 9:51 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bee, Bexar, Brooks, Cameron and 39 more114 min
May 10, 11:40 AM CDTTornado WatchSPCAransas, Atascosa, Bee, Brooks, Calhoun, Cameron and 27 more8 hr
May 10, 12:32 PM CDTSevere Thunderstorm WatchSPCBandera, Bastrop, Bexar, Blanco, Burnet, Caldwell and 25 more7 hr
May 10, 2:07 PM CDTMesoscale DiscussionSPCAransas, Atascosa, Bee, Brooks, DeWitt, Dimmit and 19 more113 min
May 10, 3:04 PM CDTMesoscale DiscussionSPCBandera, Bastrop, Bexar, Blanco, Burnet, Caldwell and 18 more116 min
May 10, 5:21 PM CDTMesoscale DiscussionSPCCrockett, Edwards, Sutton, Terrell, Val Verde54 min
May 10, 5:43 PM CDTMesoscale DiscussionSPCAransas, Atascosa, Bee, Brooks, Cameron, DeWitt and 23 more2 hr

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.