Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 53

January 30, 20114 counties in Arkansas; Bossier Parish, Caddo Parish, Louisiana; 31 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jan 30, 2011, 12:47 PM CST for 4 counties in Arkansas; Bossier Parish, Caddo Parish, Louisiana; 31 counties in Texas. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued: Jan 30, 2011, 12:47 PM CST (18:47 UTC)
Expired: Jan 30, 2011, 2:45 PM CST
In force: 118 min
Issued by: the Storm Prediction Center

All 37 counties

Columbia County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Bossier Parish, LA, Caddo Parish, LA, Anderson County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Falls County, TX, Franklin County, TX, Freestone County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hopkins County, TX, Houston County, TX, Kaufman County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, Marion County, TX, Morris County, TX, Nacogdoches County, TX, Navarro County, TX, Panola County, TX, Rains County, TX, Red River County, TX, Robertson County, TX, Rusk County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 157 km from the middle of the area, began a volume at 18:47 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 12:00Z, 6.8 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 543 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 597 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 198 m²/s²
0-3 km storm-relative helicity: 136 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.5

Open this sounding in Storm Lab

The text

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

507 
ACUS11 KWNS 301847
SWOMCD
SPC MCD 301847 
ARZ000-LAZ000-TXZ000-OKZ000-302045-

MESOSCALE DISCUSSION 0053
NWS STORM PREDICTION CENTER NORMAN OK
1247 PM CST SUN JAN 30 2011

AREAS AFFECTED...PARTS OF CNTRL AND NORTHEAST TEXAS INTO THE
ARKLATEX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 301847Z - 302045Z

THE NEED FOR A WATCH IS NOT ANTICIPATED...BUT TRENDS WILL CONTINUE
TO BE MONITORED.

ELEVATED MIXED LAYER AIR ADVECTING NORTHEAST OF THE LOWER RIO GRANDE
VALLEY...BENEATH A MID-LEVEL COLD TROUGH ASSOCIATED WITH A LOW
AMPLITUDE SHORT WAVE IMPULSE LIFTING THROUGH EASTERN TEXAS...IS
CONTRIBUTING TO AN ENVIRONMENT FAVORABLE FOR VIGOROUS CONVECTIVE
DEVELOPMENT THIS AFTERNOON.  DESTABILIZATION IS BECOMING MAXIMIZED
IN A NARROW PRE-SURFACE COLD FRONTAL CORRIDOR...ROUGHLY FROM NEAR
THE WACO/TEMPLE AREA NORTHEASTWARD TOWARD TEXARKANA...WHERE MIXED
LAYER CAPE IS NOW ON THE ORDER OF 1000-1500 J/KG...AND COULD
INCREASE A BIT FURTHER WITH ADDITIONAL SURFACE HEATING.  THIS IS
GENERALLY WELL NORTH OF THE MID/UPPER JET CORE NOSING ACROSS THE
WESTERN GULF COAST REGION...AND DEEP LAYER FLOW FIELDS AND SHEAR ARE
RATHER WEAK...BUT THERMODYNAMIC PROFILES APPEAR SUPPORTIVE OF THE
RISK FOR HAIL AND WIND GUSTS WHICH COULD AT LEAST APPROACH SEVERE
LIMITS.  FORCING FOR UPWARD VERTICAL MOTION JUST AHEAD OF THE
MID-LEVEL CYCLONIC VORTICITY CENTER MIGRATING OUT OF CENTRAL TEXAS
TOWARD THE ARKLATEX REGION MAY SUPPORT A SIGNIFICANT INCREASE IN
BOUNDARY LAYER BASED STORM DEVELOPMENT BETWEEN NOW AND 21-22Z.  IT
IS NOT OUT OF THE QUESTION THAT SOME OF THIS ACTIVITY COULD BECOME
SEVERE...BUT ANY SEVERE THREAT IS EXPECTED TO BE FAIRLY
SHORT-LIVED...AND TEND TO DIMINISH AS ACTIVITY BECOMES EVEN MORE
WIDESPREAD LATE THIS AFTERNOON.

..KERR.. 01/30/2011

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

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

LAT...LON   32599660 33799502 33889419 33249315 32049394 30759596
            30979698 31399717 32599660

Nearby

Mesoscale Discussions in Texas, 2011 Mesoscale Discussions in Arkansas, 2011 Mesoscale Discussions in Louisiana, 2011 Every mesoscale discussion in 2011

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.