Alert archive / Texas / Mesoscale Discussions in 2012

Mesoscale Discussion 754

May 7, 20125 counties in Arkansas; 7 parishes in Louisiana; 12 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 7, 2012, 9:15 PM CDT for 5 counties in Arkansas; 7 parishes in Louisiana; 12 counties in Texas. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
May 7, 2012, 9:15 PM CDT (02:15 UTC)
Expired
May 7, 2012, 10:15 PM CDT
In force
60 min
Issued by
the Storm Prediction Center
All 24 counties

Calhoun County, AR, Columbia County, AR, Lafayette County, AR, Ouachita County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Red River Parish, LA, Webster Parish, LA, Camp County, TX, Cass County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Panola County, TX, Rusk County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 44 km from the middle of the area, began a volume at 02:18 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

Shreveport, LA (KSHV), launched 00:00Z, 2.3 hours before the alert went out and 44 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 00:00Z on 2012-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 891 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 00:00Z on 2012-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 square meters per square second.1939Sfc1 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
891 J/kg
Mixed-layer CIN
-79 J/kg
Mixed-layer LCL
1717 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
72 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.

768 
ACUS11 KWNS 080216
SWOMCD
SPC MCD 080215
ARZ000-LAZ000-TXZ000-080315-

MESOSCALE DISCUSSION 0754
NWS STORM PREDICTION CENTER NORMAN OK
0915 PM CDT MON MAY 07 2012

AREAS AFFECTED...NERN TX...SRN AR...NWRN LA

CONCERNING...SEVERE THUNDERSTORM WATCH 265...266...

VALID 080215Z - 080315Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
265...266...CONTINUES.

SUMMARY...THUNDERSTORMS WILL CONTINUE TO DRIFT SWD/SEWD AND
GRADUALLY WEAKEN WITH TIME. WW265 WILL BE ALLOWED TO EXPIRE AT 03Z.

DISCUSSION...MUCH OF WW265 HAS BEEN RAIN COOLED/STABILIZED AND MAY
BE REMOVED FROM THE WW. THE REMAINING FEW COUNTIES WILL BE ALLOWED
TO EXPIRE AS STORMS CONTINUE TO PROGRESS INTO/THROUGH NERN TX AND
LA...OUT OF 265 AND INTO/THROUGH 266. THE FRONTAL/OUTFLOW MERGER
CONTINUES TO INITIATE/SUSTAIN CONVECTION. 02Z SFCOA INDICATES
CONVECTIVE INHIBITION IS STRENGTHENING...OWING TO NOCTURNAL COOLING.
SURFACE TEMPERATURES ARE NOW GENERALLY IN THE 70S. AS SUCH...STRONG
TO SEVERE STORMS WILL LIKELY ONLY OCCUR FOR THE NEXT HOUR OR
TWO...WITH A GRADUAL WEAKENING TREND THEREAFTER.

..HURLBUT.. 05/08/2012

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

ATTN...WFO...LZK...SHV...FWD...

LAT...LON   32119543 32909564 32959523 33399508 33379457 33189404
            33379344 33719303 33979265 33959228 33389234 32669277
            32149278 31989282 31899390 31859499 31949535 32119543

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 7, 7:21 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 3 more54 min
May 7, 7:39 PM CDTSevere Thunderstorm WatchSPCBienville, Bossier, Caddo, Claiborne, De Soto, Red River and 1 more4 hr
May 7, 7:54 PM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bee, Bexar, Brazos and 40 more66 min
May 7, 9:46 PM CDTMesoscale DiscussionSPCAndrews, Borden, Crane, Crockett, Dawson, Ector and 15 more89 min
May 8, 1:42 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bexar, Comal, Dimmit, Edwards and 13 more93 min
May 8, 10:44 AM CDTMesoscale DiscussionSPCBee, Brooks, Duval, Frio, Goliad, Jim Hogg and 11 more61 min
May 8, 10:58 AM CDTSevere Thunderstorm WatchSPCAransas, Atascosa, Bee, Brooks, Calhoun, Cameron and 28 more8 hr
May 8, 1:37 PM CDTMesoscale DiscussionSPCBrewster, Culberson, El Paso, Hudspeth, Jeff Davis, Presidio and 1 more113 min
May 8, 2:07 PM CDTSevere Thunderstorm WatchSPCBrewster, Culberson, El Paso, Hudspeth, Jeff Davis, Presidio7 hr
May 8, 3:03 PM CDTMesoscale DiscussionSPCCameron, Hidalgo, Starr, Willacy87 min
May 8, 4:53 PM CDTMesoscale DiscussionSPCBrewster, Culberson, El Paso, Hudspeth, Jeff Davis, Presidio67 min
May 8, 5:47 PM CDTMesoscale DiscussionSPCCameron, Hidalgo, Kenedy, Willacy58 min

Nearby

Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Louisiana, 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.