Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 555

April 15, 2012Refugio County, San Patricio County, Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 15, 2012, 6:29 PM CDT for Refugio County, San Patricio County, Texas. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Apr 15, 2012, 6:29 PM CDT (23:29 UTC)
Expired
Apr 15, 2012, 8:00 PM CDT
In force
91 min
Issued by
the Storm Prediction Center

Counties Refugio County, TX, San Patricio County, TX

The radar

The Corpus Christi radar (KCRP), 55 km from the middle of the area, began a volume at 23:29 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, 11.5 hours before the alert went out and 61 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 2012-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1700 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 2012-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 224 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
1700 J/kg
Mixed-layer CIN
-292 J/kg
Mixed-layer LCL
780 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
224 m²/s²
0-3 km storm-relative helicity
447 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

845 
ACUS11 KWNS 152329
SWOMCD
SPC MCD 152329 
TXZ000-160100-

MESOSCALE DISCUSSION 0555
NWS STORM PREDICTION CENTER NORMAN OK
0629 PM CDT SUN APR 15 2012

AREAS AFFECTED...PORTIONS OF MIDDLE TEXAS COASTAL AREAS AND ADJACENT
COASTAL PLAIN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 152329Z - 160100Z

THE NEED FOR A WATCH IS NOT CURRENTLY ANTICIPATED...BUT TRENDS WILL
CONTINUE TO BE MONITORED FOR THE POSSIBILITY OF AN INCREASING SEVERE
THREAT.

LOCALLY ENHANCED CONVERGENCE ASSOCIATED WITH THE INTERSECTION OF AN
INLAND ADVANCING SEA-BREEZE AND SOUTHEASTWARD ADVANCING WEAK COLD
FRONT APPEARS TO HAVE BEEN THE INITIATING MECHANISM FOR ISOLATED
INTENSE CONVECTIVE DEVELOPMENT TO THE SOUTHWEST OF VICTORIA.  THIS
IS BEING SUPPORTED BY FAIRLY LARGE CAPE OF 2000-3000+ J/KG...IN THE
PRESENCE OF HIGH BOUNDARY LAYER MOISTURE AND STEEP MID-LEVEL LAPSE
RATES.  DEEP LAYER SHEAR BENEATH 30-50 KT SOUTHERLY 500 MB FLOW IS
AT LEAST MARGINALLY SUFFICIENT FOR SUBSTANTIVE MID-LEVEL UPDRAFT
ROTATION.  AIDED BY A FOCUSED AREA OF ENHANCED LOWER/MID
TROPOSPHERIC WARM ADVECTION...ACTIVITY MAY PERSIST AT LEAST ANOTHER
SEVERAL HOURS.  IT IS NOT CLEAR THAT A SUBSTANTIAL INCREASE IN
COVERAGE WILL OCCUR...BUT THE RISK FOR LARGE HAIL COULD
CONTINUE...ALONG WITH SOME POTENTIAL FOR AN ISOLATED
TORNADO...PERHAPS EVENTUALLY A LOCALIZED STRONG DOWNBURST...MAINLY
WEST/NORTHWEST OF CORPUS CHRISTI THROUGH 00-02Z.

..KERR.. 04/15/2012

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

ATTN...WFO...CRP...

LAT...LON   28159774 28559756 28759725 28589692 28129706 27899744
            27969772 28159774

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 14, 10:11 PM CDTMesoscale DiscussionSPCBorden, Childress, Collingsworth, Cottle, Crosby, Dawson and 17 more34 min
Apr 14, 10:29 PM CDTSevere Thunderstorm WatchSPCAndrews, Archer, Baylor, Borden, Briscoe, Callahan and 43 more6 hr
Apr 15, 9:25 AM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Delta, Franklin, Gregg and 10 more95 min
Apr 15, 3:44 PM CDTMesoscale DiscussionSPCPanola, Shelby91 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.