SPC MESOSCALE DISCUSSION 2237 FOR...SOUTH TX...
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...

VALID 150710Z - 151000Z

NUMEROUS TSTMS SHOULD CONTINUE ACROSS SOUTH-CENTRAL TX THROUGH 10Z
WITH A THREAT OF SUPERCELLS CAPABLE OF PRODUCING ISOLATED/BRIEF
TORNADOES AND SOME HAIL. AREA IS BEING MONITORED CLOSELY BUT NO
TSTM WATCH IS CURRENTLY ANTICIPATED. 

MESOANALYSIS INDICATES STRONG LOW LEVEL CONVERGENCE ALONG INVERTED
TROUGH FROM EDWARDS COUNTY NEWD ACROSS KIMBLE AND MENARD COUNTIES.
SURFACE WARM FRONT APPEARS TO INTERSECT THE TROUGH AXIS NEAR
EDWARDS COUNTY AND CONTINUES ESEWD ACROSS BANDERA COUNTY WHERE
PERSISTENT SUPERCELL WAS OBSERVED. LARGE SCALE ASCENT ACROSS THE
AREA SHOULD REMAIN QUITE STRONG AS PRONOUNCED MID/UPPER LEVEL
DIFLUENCE CONTINUES TO THE EAST OF THE SLOW MOVING UPPER LOW
CENTERED NEAR ELP. THIS ASCENT WILL CONTINUE TO ACT UPON A
CONTINUOUS SUPPLY OF RICH LOW LEVEL MOISTURE STREAMING NWWD ACROSS
THE TX COASTAL PLAIN AND THE LOWER RIO GRANDE VALLEY. IN
ADDITION...STEEP MID LEVEL LAPSE RATE PLUME WILL PERSIST WITHIN
SSWLY MID LEVEL FLOW COMING OFF THE MEXICAN PLATEAU AND CONTRIBUTE
TO MLCAPE VALUES OF 1000-1500 J/KG ALONG AND SOUTH OF THE WARM
FRONT. LOW LEVEL SHEAR AND STORM INFLOW APPEAR TO BE STRONGEST
INVOF WARM FRONT WHERE STRONGLY VEERED WIND FIELDS WERE EVIDENT IN
AREA VWPS AND INDICATED 0-3KM HELICITY BETWEEN 200-300 M2/S2 GIVEN
OBSERVED STORM MOTION. HOWEVER...VWP DATA AND MODEL FCST SOUNDINGS
ALSO SHOW WEAK MID LEVEL STORM RELATIVE FLOW WHICH WOULD TEND TO
WEAKEN STORM UPDRAFTS DUE TO PRECIPITATION LOADING. NONETHELESS...
GIVEN THE STRONG FORCING AND INSTABILITY IN PLACE...THERE REMAINS
A SMALL THREAT OF ISOLATED WEAK/BRIEF TORNADOES AND PERHAPS SEVERE
HAIL ACROSS SOUTH TX THROUGH 10Z.

PERSISTENT UPSLOPE FLOW/CELL MERGERS AND MESOSCALE FORCING IN THE
VERY MOIST ENVIRONMENT WERE ALSO CONTRIBUTING TO A FLASH FLOOD
THREAT. PLEASE SEE MESOSCALE DISCUSSION NUMBER 2236 FOR DETAILS ON
THIS SITUATION.

..CARBIN.. 11/15/01