Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 447

April 4, 20127 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2012, 3:32 PM CDT for 7 counties in Texas. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued
Apr 4, 2012, 3:32 PM CDT (20:32 UTC)
Expired
Apr 4, 2012, 5:00 PM CDT
In force
88 min
Issued by
the Storm Prediction Center

Counties Aransas County, TX, Brazoria County, TX, Calhoun County, TX, Galveston County, TX, Kleberg County, TX, Matagorda County, TX, Nueces County, TX

The radar

The Corpus Christi radar (KCRP), 153 km from the middle of the area, began a volume at 20:32 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 12:00Z, 8.5 hours before the alert went out and 142 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 2012-04-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3692 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 2012-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -42 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
3692 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
499 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
-42 m²/s²
0-3 km storm-relative helicity
18 m²/s²
Significant tornado parameter
-0.5
Supercell composite
-3.1

Open this sounding in Storm Lab

The text

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

177 
ACUS11 KWNS 042032
SWOMCD
SPC MCD 042032 
TXZ000-042200-

MESOSCALE DISCUSSION 0447
NWS STORM PREDICTION CENTER NORMAN OK
0332 PM CDT WED APR 04 2012

AREAS AFFECTED...MIDDLE AND SRN TX COAST

CONCERNING...SEVERE THUNDERSTORM WATCH 139...

VALID 042032Z - 042200Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 139
CONTINUES.

SEVERE THREAT CONTINUES INVOF THE TX COAST/WITHIN WW 139.

LATEST RADAR IMAGERY SHOWS STORMS CONTINUING INVOF A SEA-BREEZE
BOUNDARY LOCATED JUST INLAND FROM THE TX COAST.  SEVERAL STORMS HAVE
BEEN SUPERCELLULAR OVER THE PAST 1-2 HOURS -- PARTICULARLY ACROSS
NRN-MOST PORTIONS OF THE AREA...WHERE SLIGHTLY STRONGER FLOW ALOFT
IS INDICATED.

GIVEN THE VERY MOIST/UNSTABLE ENVIRONMENT AND SHEAR SUFFICIENT FOR
SUPERCELLS...EXPECT THREAT FOR HAIL AND LOCALLY DAMAGING WINDS TO
CONTINUE.  IN ADDITION...WITH FAIRLY SLOW STORM MOVEMENT AND
CONVECTIVE CELLS MOVING REPEATEDLY OVER SOME OF THE SAME
AREAS...LOCALLY HEAVY RAINFALL WILL ALSO OCCUR.

..GOSS.. 04/04/2012

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

ATTN...WFO...HGX...CRP...BRO...

LAT...LON   29649506 29269475 28549532 27119707 27029791 27169825
            29479592 29649506

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 3, 7:35 PM CDTSevere Thunderstorm WatchSPCAustin, Bastrop, Brazos, Burleson, Colorado, Fayette and 13 more7 hr
Apr 3, 8:47 PM CDTMesoscale DiscussionSPCAngelina, Cherokee, Houston, Nacogdoches, Panola, Rusk and 3 more58 min
Apr 3, 9:48 PM CDTSevere Thunderstorm WatchSPCAngelina, Cherokee, Hardin, Jasper, Jefferson, Nacogdoches and 8 more8 hr
Apr 3, 11:24 PM CDTMesoscale DiscussionSPCAngelina, Austin, Colorado, Jasper, Lavaca, Montgomery and 10 more96 min
Apr 4, 2:29 AM CDTMesoscale DiscussionSPCChambers, Hardin, Harris, Jefferson, Liberty, Orange and 2 more91 min
Apr 4, 12:19 PM CDTMesoscale DiscussionSPCAransas, Austin, Bee, Brazoria, Calhoun, Chambers and 25 more86 min
Apr 4, 12:55 PM CDTSevere Thunderstorm WatchSPCAransas, Bee, Brazoria, Brooks, Calhoun, Cameron and 19 more6 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; radar from the NEXRAD Level II archive.