Alert archive / Texas / Mesoscale Discussions in 2006

Mesoscale Discussion 2321

December 29, 2006Beauregard Parish, Calcasieu Parish, Louisiana; 81 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Dec 29, 2006, 5:09 PM CST for Beauregard Parish, Calcasieu Parish, Louisiana; 81 counties in Texas. It was in force for 36 min.

The area

The outline as issued.

The facts

Issued
Dec 29, 2006, 5:09 PM CST (23:09 UTC)
Expired
Dec 29, 2006, 5:45 PM CST
In force
36 min
Issued by
the Storm Prediction Center
All 83 counties

Beauregard Parish, LA, Calcasieu Parish, LA, Anderson County, TX, Angelina County, TX, Aransas County, TX, Austin County, TX, Bastrop County, TX, Bee County, TX, Bell County, TX, Bosque County, TX, Brazoria County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Calhoun County, TX, Chambers County, TX, Cherokee County, TX, Colorado County, TX, Comal County, TX, Coryell County, TX, DeWitt County, TX, Ellis County, TX, Falls County, TX, Fayette County, TX, Fort Bend County, TX, Freestone County, TX, Galveston County, TX, Goliad County, TX, Gonzales County, TX, Grimes County, TX, Guadalupe County, TX, Hamilton County, TX, Hardin County, TX, Harris County, TX, Hays County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Houston County, TX, Jackson County, TX, Jasper County, TX, Jefferson County, TX, Jim Wells County, TX, Johnson County, TX, Karnes County, TX, Kleberg County, TX, Lavaca County, TX, Lee County, TX, Leon County, TX, Liberty County, TX, Limestone County, TX, Live Oak County, TX, Madison County, TX, Matagorda County, TX, McLennan County, TX, Milam County, TX, Montgomery County, TX, Nacogdoches County, TX, Navarro County, TX, Newton County, TX, Nueces County, TX, Orange County, TX, Polk County, TX, Refugio County, TX, Robertson County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, San Patricio County, TX, Shelby County, TX, Somervell County, TX, Travis County, TX, Trinity County, TX, Tyler County, TX, Victoria County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Wharton County, TX, Williamson County, TX, Wilson County, TX

The radar

The Houston radar (KHGX), 124 km from the middle of the area, began a volume at 23:10 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

Lake Charles Mun, LA (KLCH), launched 12:00Z, 11.2 hours before the alert went out and 272 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, Lake Charles Mun, LA at 12:00Z on 2006-12-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 119 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, Lake Charles Mun, LA at 12:00Z on 2006-12-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 324 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
119 J/kg
Mixed-layer CIN
-168 J/kg
Mixed-layer LCL
485 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
324 m²/s²
0-3 km storm-relative helicity
363 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.4

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 292309
SWOMCD
SPC MCD 292309 
LAZ000-TXZ000-292345-

MESOSCALE DISCUSSION 2321
NWS STORM PREDICTION CENTER NORMAN OK
0509 PM CST FRI DEC 29 2006

AREAS AFFECTED...PARTS OF CENTRAL AND E TX INCLUDING COASTAL WATERS
EWD TO SWRN LA

CONCERNING...TORNADO WATCH 886...

VALID 292309Z - 292345Z

TORNADO THREAT EXPECTED TO DEVELOP EWD INTO SE AND PARTS OF E TX BY
EARLY EVENING.  THUS...NEW TORNADO WATCH BEING CONSIDERED FOR SE TX
AND POTENTIALLY PARTS OF SW LA.  THIS NEW WW WILL ALSO INCLUDE VALID
PARTS OF WW 886 TO THE EAST OF COLD FRONT.

LATE AFTERNOON SURFACE ANALYSIS INDICATED A TRIPLE POINT LOW OVER
CENTRAL TX IN THE VICINITY OF BOSQUE COUNTY...WITH A WARM FRONT
EXTENDING EWD INTO WEST CENTRAL LA.  A SECOND WARM FRONT EXTENDED
FROM THE NWRN GULF TO NEAR GLS AND THEN NWWD INTO ANDERSON COUNTY OR
ABOUT 45 SSW TYR.  STORMS DEVELOPING IN THE VICINITY OF THIS SECOND
WARM FRONT ARE EXPECTED TO POSE A TORNADO THREAT...GIVEN THE CURRENT
EXISTENCE OF STRONG LOW LEVEL DIRECTIONAL SHEAR WITH 0-1 KM SRH
VALUES EXCEEDING 400 M2/S2.  FURTHER INCREASE IN DEEP LAYER VEERING
WIND PROFILE IS EXPECTED THROUGH THIS EVENING OVER AND EAST OF WW
886 INTO SW LA...RESULTING IN A CONTINUED POTENTIAL FOR SUPERCELLS
AND ATTENDANT TORNADO THREAT.

PERSISTENT MOISTURE INFLUX INTO THE WARM SECTOR WILL MAINTAIN AT
LEAST MARGINAL INSTABILITY FOR THUNDERSTORMS TO CONTINUE TO DEVELOP
THROUGH THE EVENING ALLOWING FOR LOW LCLS/LFCS AND ENHANCING TORNADO
POTENTIAL.

..PETERS.. 12/29/2006

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

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

31489346 30089320 29459351 29019462 28479532 27529690
27309772 27329838 28099827 29859830 30759827 31759816
32459816 32549673 32319544 32199460 31879408

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 29, 11:42 AM CSTMesoscale DiscussionSPCAustin, Bastrop, Bell, Blanco, Bosque, Brazos and 44 more3 hr
Dec 29, 12:42 PM CSTTornado WatchSPCAnderson, Aransas, Atascosa, Austin, Bastrop, Bee and 67 more5 hr
Dec 29, 1:09 PM CSTMesoscale DiscussionSPCArcher, Clay, Collin, Cooke, Dallas, Delta and 22 more66 min
Dec 29, 1:37 PM CSTTornado WatchSPCArcher, Baylor, Clay, Collin, Cooke, Dallas and 19 more6 hr
Dec 29, 3:24 PM CSTMesoscale DiscussionSPCAnderson, Aransas, Archer, Atascosa, Austin, Bastrop and 92 more2 hr
Dec 29, 5:38 PM CSTTornado WatchSPCAnderson, Angelina, Aransas, Austin, Bastrop, Bee and 67 more10 hr

Nearby

Mesoscale Discussions in Texas, 2006Mesoscale Discussions in Louisiana, 2006Every mesoscale discussion in 2006

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.