Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 438

April 3, 2012Little River County, Miller County, Arkansas; 24 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 3, 2012, 5:00 PM CDT for Little River County, Miller County, Arkansas; 24 counties in Texas. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
Apr 3, 2012, 5:00 PM CDT (22:00 UTC)
Expired
Apr 3, 2012, 6:00 PM CDT
In force
60 min
Issued by
the Storm Prediction Center
All 26 counties

Little River County, AR, Miller County, AR, Anderson County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Delta County, TX, Falls County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Henderson County, TX, Hopkins County, TX, Kaufman County, TX, Leon County, TX, Limestone County, TX, Marion County, TX, Morris County, TX, Navarro County, TX, Rains County, TX, Red River County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 134 km from the middle of the area, began a volume at 22:03 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

Shreveport, LA (KSHV), launched 12:00Z, 10.0 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, Shreveport, LA at 12:00Z on 2012-04-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1328 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, Shreveport, LA at 12:00Z on 2012-04-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 148 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
1328 J/kg
Mixed-layer CIN
-64 J/kg
Mixed-layer LCL
475 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
148 m²/s²
0-3 km storm-relative helicity
286 m²/s²
Significant tornado parameter
0.0
Supercell composite
8.5

Open this sounding in Storm Lab

The text

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

159 
ACUS11 KWNS 032201
SWOMCD
SPC MCD 032200
ARZ000-LAZ000-TXZ000-OKZ000-032300-

MESOSCALE DISCUSSION 0438
NWS STORM PREDICTION CENTER NORMAN OK
0500 PM CDT TUE APR 03 2012

AREAS AFFECTED...NERN/E-CNTRL TX...FAR SERN OK/SWRN AR

CONCERNING...TORNADO WATCH 133...135...

VALID 032200Z - 032300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 133...135...CONTINUES.

PRIMARY TORNADO RISK WILL REMAIN WITH SEMI-DISCRETE SUPERCELLS
PERSISTING ALONG REMNANT OUTFLOW BOUNDARY OVER FAR NERN TX AND
PERHAPS DEVELOPING INTO EXTREME SERN OK/SWRN AR. MESOCYCLONE
CIRCULATIONS HAVE BEEN IN W/E-ORIENTED CONVECTION ACROSS FAR NERN TX
AND ALONG THE NRN PORTION OF A QLCS THAT EXTENDED FROM 30 W PRX TO
20 S ACT AS OF 2145Z...IN AN ENVIRONMENT CHARACTERIZED BY 0-1 KM
SHEAR AROUND 20-25 KT. ADDITIONAL PRE-FRONTAL TSTM DEVELOPMENT IS
POSSIBLE AND SHOULD MAINTAIN A CONTINUED TORNADO RISK FOR THE NEXT
FEW HOURS. LOW-LEVEL SHEAR IS WEAKER WITH S/SWRN EXTENT ALONG THE
QLCS PER THE GRK VWP AND GIVEN THE UNDERCUTTING NATURE OF THE
COMPOSITE COLD FRONT/OUTFLOW...LIKELY MITIGATE THE TORNADO THREAT
RELATIVE TO THE RED RIVER VICINITY.

..GRAMS.. 04/03/2012

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

ATTN...WFO...SHV...HGX...FWD...

LAT...LON   33699553 33889508 33889475 33859424 33519368 33209369
            32979374 32789399 32439457 31919518 31229599 31239670
            31269704 31749686 32809623 33409592 33699553

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 3, 1:42 PM CDTMesoscale DiscussionSPCChicot93 min
Apr 3, 2:22 PM CDTSevere Thunderstorm WatchSPCColumbia, Hempstead, Lafayette, Nevada, Union8 hr
Apr 3, 2:36 PM CDTTornado WatchSPCHoward, Little River, Miller, Sevier7 hr
Apr 3, 3:05 PM CDTMesoscale DiscussionSPCHempstead, Howard, Little River, Montgomery, Nevada, Pike and 2 more85 min
Apr 3, 3:43 PM CDTSevere Thunderstorm WatchSPCBoone, Bradley, Calhoun, Clark, Crawford, Dallas and 16 more6 hr
Apr 3, 5:24 PM CDTMesoscale DiscussionSPCAshley, Chicot, Union66 min
Apr 3, 6:53 PM CDTMesoscale DiscussionSPCColumbia, Hempstead, Lafayette, Little River, Miller, Nevada and 1 more67 min
Apr 2, 7:17 PM CDTMesoscale DiscussionSPCHansford, Hemphill, Hutchinson, Lipscomb, Ochiltree, Roberts58 min
Apr 2, 9:12 PM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Hardeman, Haskell, Hemphill and 12 more63 min
Apr 2, 10:51 PM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Clay, Jack, Montague, Wichita and 2 more5 hr
Apr 2, 11:45 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coleman, Comanche, Concho, Eastland and 17 more2 hr
Apr 3, 1:14 AM CDTMesoscale DiscussionSPCArcher, Baylor, Callahan, Clay, Jack, Montague and 7 more2 hr
Apr 3, 3:32 AM CDTMesoscale DiscussionSPCArcher, Baylor, Borden, Brown, Callahan, Clay and 24 more88 min
Apr 3, 8:36 AM CDTMesoscale DiscussionSPCArcher, Bell, Blanco, Bosque, Brown, Burnet and 40 more84 min
Apr 3, 9:18 AM CDTSevere Thunderstorm WatchSPCBosque, Clay, Collin, Comanche, Cooke, Coryell and 33 more8 hr
Apr 3, 11:47 AM CDTMesoscale DiscussionSPCBosque, Collin, Cooke, Coryell, Dallas, Delta and 32 more118 min
Apr 3, 12:08 PM CDTTornado WatchSPCAnderson, Bell, Bosque, Collin, Coryell, Dallas and 30 more9 hr
Apr 3, 1:12 PM CDTMesoscale DiscussionSPCBosque, Collin, Dallas, Denton, Ellis, Erath and 16 more93 min
Apr 3, 1:46 PM CDTMesoscale DiscussionSPCCamp, Cass, Cherokee, Franklin, Gregg, Harrison and 9 more89 min
Apr 3, 2:21 PM CDTMesoscale DiscussionSPCLamar, Montague84 min
Apr 3, 4:38 PM CDTMesoscale DiscussionSPCAustin, Bastrop, Brazos, Burleson, Caldwell, Fayette and 10 more67 min

Nearby

Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Arkansas, 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.