Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 239

March 8, 20129 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 8, 2012, 11:36 PM CST for 9 counties in Texas. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued
Mar 8, 2012, 11:36 PM CST (05:36 UTC)
Expired
Mar 9, 2012, 12:30 AM CST
In force
54 min
Issued by
the Storm Prediction Center

Counties Brooks County, TX, Dimmit County, TX, Duval County, TX, Jim Hogg County, TX, Jim Wells County, TX, La Salle County, TX, McMullen County, TX, Webb County, TX, Zapata County, TX

The radar

The Corpus Christi radar (KCRP), 149 km from the middle of the area, began a volume at 05:37 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, 5.6 hours before the alert went out and 166 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 2012-03-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1750 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 2012-03-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 137 square meters per square second.1939587897Sfc1 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
1750 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
661 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
137 m²/s²
0-3 km storm-relative helicity
179 m²/s²
Significant tornado parameter
0.8
Supercell composite
5.3

Open this sounding in Storm Lab

The text

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

637 
ACUS11 KWNS 090536
SWOMCD
SPC MCD 090536 
TXZ000-090630-

MESOSCALE DISCUSSION 0239
NWS STORM PREDICTION CENTER NORMAN OK
1136 PM CST THU MAR 08 2012

AREAS AFFECTED...DEEP S TX

CONCERNING...SEVERE THUNDERSTORM WATCH 70...

VALID 090536Z - 090630Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 70
CONTINUES.

LIMITED SEVERE THREAT CONTINUES ACROSS MUCH OF WW 70.

LATEST RADAR LOOP SHOWS THAT THE INITIAL SEVERE STORMS ACROSS PARTS
OF THE WRN HALF OF WW 70 HAVE DISSIPATED...WHICH HAS ENDED THE
IMMEDIATE THREAT FOR LARGE HAIL ACROSS THIS REGION.

AS THE FRONT CONTINUES ADVANCING SWD ACROSS THIS AREA...ELEVATED
CONVECTIVE DEVELOPMENT IS EVIDENT -- ALBEIT SUB-SEVERE ATTM. 
STILL...WITH ELEVATED CAPE AND AMBIENT SHEAR SUFFICIENT FOR
ORGANIZED UPDRAFTS...LIMITED THREAT FOR HAIL ACROSS THIS REGION
SUPPORTS CONTINUATION OF WW 70 ATTM.

..GOSS.. 03/09/2012

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

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

LAT...LON   26819935 28119997 28439989 28559953 28539873 28189806
            26939779 26549851 26819935

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 8, 7:32 PM CSTMesoscale DiscussionSPCAtascosa, Austin, Bandera, Bastrop, Bee, Bexar and 33 more88 min
Mar 8, 8:58 PM CSTSevere Thunderstorm WatchSPCBrooks, Duval, Hidalgo, Jim Hogg, Jim Wells, La Salle and 5 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.