Mesoscale Discussion 2006

Issued

Sep 29, 2012, 5:23 PM CDT (22:23 UTC)

Expired

Sep 29, 2012, 7:00 PM CDT

In force

97 min

Issued by

the Storm Prediction Center

Chance of a watch

20%

Counties Aransas County, TX, Austin County, TX, Calhoun County, TX, Colorado County, TX, DeWitt County, TX, Fayette County, TX, Fort Bend County, TX, Goliad County, TX, Jackson County, TX, Lavaca County, TX, Matagorda County, TX, Refugio County, TX, San Patricio County, TX, Victoria County, TX, Wharton County, TX

The Corpus Christi radar (KCRP), 141 km from the middle of the area, began a volume at 22:23 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.

819 
ACUS11 KWNS 292223
SWOMCD
SPC MCD 292223 
TXZ000-300000-

MESOSCALE DISCUSSION 2006
NWS STORM PREDICTION CENTER NORMAN OK
0523 PM CDT SAT SEP 29 2012

AREAS AFFECTED...PARTS OF THE MIDDLE TX COAST AND COASTAL PLAIN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 292223Z - 300000Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...THE POTENTIAL EXISTS FOR ADDITIONAL EPISODIC STORMS
PRODUCING...AT TIMES...SOME WEAK LOW LEVEL ROTATION.  AN ISOLATED
BRIEF TORNADO AND/OR STRONGER WIND GUST CANNOT BE RULED OUT INTO THE
EVENING.

DISCUSSION...A MOISTURE-LADEN AIR MASS WAS OBSERVED ACROSS THE TX
COAST INTO THE COASTAL PLAIN REGION WITH SURFACE DEWPOINTS IN THE
LOW-MID 70S AND PW VALUES AROUND 2.5 INCH.  DESPITE WEAK LAPSE
RATES...THIS RICH MOISTURE AND SURFACE HEATING IN THE WAKE OF
EARLIER CLOUDS HAS BOOSTED MLCAPE TO 1000-1500 J/KG.  SURFACE
ANALYSIS SHOWED A SYNOPTIC LOW 20 N SAT...WHILE STREAMLINE ANALYSES
INFERRED A COUPLE OF SUB-SYNOPTIC LOW PRESSURE AREAS NNEWD IN
LLANO/BURNET COUNTIES TX...AND FARTHER NE BETWEEN WACO AND COLLEGE
STATION.  VISIBLE SATELLITE IMAGERY AND THE STREAMLINE ANALYSIS ALSO
INDICATED BANDS OF LOW LEVEL CONVERGENCE EXTENDING SWD FROM EACH OF
THE AFOREMENTIONED LOWS.  OBJECTIVE ANALYSES SUGGESTED THE ERN MOST
BAND EXTENDING SWD FROM THE ACT/CLL LOW AND AN AREA OF N-S ORIENTED
LOW LEVEL CONFLUENCE EXTENDING NWD FROM OFFSHORE BRO TO INVOF VCT
AREA HAD THE STRONGEST CONVERGENCE.  CONVECTION AND EMBEDDED TSTMS
HAVE BEEN GENERALLY CONFINED TO THESE BANDS OF CONFLUENCE.  ALTHOUGH
CAPE IS SUFFICIENT FOR TSTM DEVELOPMENT...THE WARM CLOUD PROCESSES
AND WEAK LAPSE RATES ARE TENDING TO INHIBIT MORE ROBUST/SUSTAINED
UPDRAFTS.  EFFECTIVE BULK SHEAR OF 30-35 KT IS SUFFICIENT FOR STORM
ORGANIZATION...THOUGH THE DURATION OF THIS ACTIVITY SHOULD REMAIN
SHORT GIVEN THE SOMEWHAT UNFAVORABLE THERMODYNAMIC ENVIRONMENT...AND
LACK OF DISCRETE CONVECTION.  

LOW LCLS AND A N-S ORIENTED CORRIDOR OF GREATER EFFECTIVE SRH OF
100-200 M2/S2 EXTENDING FROM OFFSHORE THE SRN-MIDDLE GULF COAST
INLAND TO I-10 BETWEEN SAT/HOU ARE SUPPORTIVE FOR SOME LOW LEVEL
ROTATION WITH A BRIEF TORNADO POSSIBLE.  HOWEVER...THE LIKELIHOOD
FOR LONGER LIVED STORMS AND GREATER COVERAGE OF STRONGER ACTIVITY IS
LOW AND AT THIS TIME DOES NOT WARRANT A WATCH.

..PETERS/CARBIN.. 09/29/2012

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

ATTN...WFO...HGX...CRP...EWX...

LAT...LON   27829692 27979761 28689764 29649731 30119682 29749585
            29059549 28599561 27829692

Mesoscale Discussions in Texas, 2012Every mesoscale discussion in 2012

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.