Alert archive / Texas / Mesoscale Discussions in 2008

Mesoscale Discussion 921

May 14, 200813 parishes in Louisiana; 40 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 14, 2008, 7:31 AM CDT for 13 parishes in Louisiana; 40 counties in Texas. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued
May 14, 2008, 7:31 AM CDT (12:31 UTC)
Expired
May 14, 2008, 9:30 AM CDT
In force
119 min
Issued by
the Storm Prediction Center
All 53 counties

Beauregard Parish, LA, Bienville Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Rapides Parish, LA, Red River Parish, LA, Sabine Parish, LA, Vernon Parish, LA, Winn Parish, LA, Anderson County, TX, Angelina County, TX, Austin County, TX, Bastrop County, TX, Bell County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Cherokee County, TX, Falls County, TX, Fayette County, TX, Freestone County, TX, Grimes County, TX, Hardin County, TX, Houston County, TX, Jasper County, TX, Lee County, TX, Leon County, TX, Liberty County, TX, Limestone County, TX, Madison County, TX, Milam County, TX, Montgomery County, TX, Nacogdoches County, TX, Newton County, TX, Panola County, TX, Polk County, TX, Robertson County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Travis County, TX, Trinity County, TX, Tyler County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Williamson County, TX

The radar

The Ft Hood radar (KGRK), 184 km from the middle of the area, began a volume at 12:31 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

Fort Worth, TX (KFWD), launched 12:00Z, 0.5 hours before the alert went out and 249 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, Fort Worth, TX at 12:00Z on 2008-05-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1363 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 12:00Z on 2008-05-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
1363 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
514 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
-53 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.5

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 141232
SWOMCD
SPC MCD 141231 
LAZ000-TXZ000-141430-

MESOSCALE DISCUSSION 0921
NWS STORM PREDICTION CENTER NORMAN OK
0731 AM CDT WED MAY 14 2008

AREAS AFFECTED...EAST/NORTHEAST TX INTO NORTHERN LA

CONCERNING...SEVERE THUNDERSTORM WATCH 318...

VALID 141231Z - 141430Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 318
CONTINUES.

SEVERE THUNDERSTORM WATCH 318 CONTINUES UNTIL 15Z...HOWEVER AN
ADDITIONAL /OR REPLACEMENT/ WATCH COULD BE NEEDED WITHIN THE NEXT
HOUR OR SO ACROSS EAST/NORTHEAST TX INTO LA.

MCV-AIDED/RAIN-EMBEDDED BOW HEAD CIRCULATION CONTINUES TO STEADILY
ADVANCE EAST-NORTHEAST ACROSS EAST CENTRAL TX BETWEEN I-35/I-45
EARLY THIS MORNING...ACROSS FALLS COUNTY TX AS OF 1215Z. A
RAIN-REINFORCED BOUNDARY LIES NORTHEASTWARD AHEAD OF THIS PERSISTENT
CIRCULATION INTO NORTHEAST TX/NORTH CENTRAL LA...WITH LOWER 70S F
TEMPERATURES AND DEWPOINTS ALONG/SOUTH OF THIS SURFACE BOUNDARY.
ALTHOUGH MCS-LEADING PRECIPITATION IS COMMON ACROSS NORTHEAST/EAST
CENTRAL TX AT THIS TIME...POCKETS OF LOCAL HEATING AND THE MOIST
NATURE OF THE AIRMASS SUGGEST A SOMEWHAT CONCENTRATED SEVERE THREAT
WILL REMAIN ALONG/SOUTH OF THIS BOUNDARY ACROSS EAST
CENTRAL/NORTHEAST TX INTO LA THROUGH EARLY AFTERNOON. THE PRIMARY
RISKS WOULD BE THE POSSIBILITY OF DAMAGING WINDS AND PERHAPS A FEW
TORNADOES. AN ADDITIONAL WATCH MAY BE NEEDED SOON. 

OTHERWISE...HEAVY RAINFALL WILL REMAIN A CONCERN WITHIN THIS
CORRIDOR...AND AN ISOLATED/MAINLY HAIL THREAT WILL CONTINUE ACROSS
THE REMAINING MCS-TRAILING PORTION OF WW 318.

..GUYER.. 05/14/2008

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

ATTN...WFO...JAN...LCH...SHV...HGX...FWD...EWX...

30649867 31669675 32219511 32649258 31499191 30509356
29539698

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 13, 7:11 PM CDTMesoscale DiscussionSPCAcadia, Ascension, Assumption, Avoyelles, Bienville, Bossier and 45 more2 hr
May 14, 2:28 AM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, De Soto, Natchitoches and 3 more92 min
May 14, 7:50 AM CDTTornado WatchSPCBeauregard, Caldwell, De Soto, Grant, LaSalle, Natchitoches and 5 more7 hr
May 14, 10:23 AM CDTMesoscale DiscussionSPCBeauregard, Bienville, De Soto, Grant, Jackson, LaSalle and 7 more97 min
May 14, 1:55 PM CDTMesoscale DiscussionSPCAscension, Avoyelles, Catahoula, Concordia, East Baton Rouge, East Feliciana and 10 more65 min
May 14, 2:04 PM CDTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 31 more7 hr
May 14, 5:12 PM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 34 more63 min
May 13, 8:05 PM CDTMesoscale DiscussionSPCBrown, Clay, Coleman, Comanche, Cooke, Denton and 10 more85 min
May 13, 8:29 PM CDTMesoscale DiscussionSPCBandera, Blanco, Burnet, Comal, Concho, Edwards and 15 more91 min
May 13, 8:53 PM CDTSevere Thunderstorm WatchSPCAnderson, Bell, Bosque, Brown, Callahan, Coke and 56 more7 hr
May 13, 9:54 PM CDTSevere Thunderstorm WatchSPCBastrop, Brazos, Burleson, Caldwell, Comal, Fayette and 5 more6 hr
May 13, 11:41 PM CDTMesoscale DiscussionSPCBastrop, Bell, Blanco, Bosque, Brazos, Burleson and 18 more94 min
May 14, 12:50 AM CDTMesoscale DiscussionSPCArcher, Armstrong, Baylor, Briscoe, Childress, Clay and 26 more85 min
May 14, 1:19 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bexar, Blanco, Comal, Dimmit and 19 more56 min
May 14, 1:40 AM CDTTornado WatchSPCAtascosa, Bandera, Bexar, Comal, Dimmit, Edwards and 12 more6 hr
May 14, 2:59 AM CDTMesoscale DiscussionSPCAustin, Bastrop, Bell, Blanco, Brazos, Burleson and 26 more91 min
May 14, 3:39 AM CDTSevere Thunderstorm WatchSPCAustin, Bastrop, Bell, Blanco, Brazos, Burleson and 25 more6 hr
May 14, 5:13 AM CDTMesoscale DiscussionSPCAustin, Bastrop, Bell, Blanco, Brazos, Burleson and 29 more92 min
May 14, 5:38 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bexar, Edwards, Frio, Kerr and 7 more97 min
May 14, 6:42 AM CDTMesoscale DiscussionSPCAustin, Bastrop, Bell, Blanco, Brazos, Burleson and 30 more63 min
May 14, 12:12 PM CDTMesoscale DiscussionSPCAndrews, Dawson, Gaines, Terry, Yoakum93 min
May 14, 12:47 PM CDTTornado WatchSPCAndrews, Borden, Cochran, Coke, Crane, Dawson and 22 more6 hr
May 14, 3:33 PM CDTMesoscale DiscussionSPCCrockett, Edwards, Kerr, Kimble, Kinney, Menard and 5 more27 min
May 14, 3:50 PM CDTTornado WatchSPCBandera, Blanco, Brown, Burnet, Callahan, Coleman and 37 more7 hr
May 14, 3:58 PM CDTMesoscale DiscussionSPCAnderson, Bastrop, Bell, Brazos, Burleson, Falls and 9 more92 min
May 14, 6:08 PM CDTMesoscale DiscussionSPCAndrews, Borden, Cochran, Coke, Crane, Crosby and 27 more67 min
May 14, 6:40 PM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Foard, Hardeman, Knox and 2 more95 min

Nearby

Mesoscale Discussions in Texas, 2008Mesoscale Discussions in Louisiana, 2008Every mesoscale discussion in 2008

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.