000
ACUS11 KWNS 231805
SWOMCD
SPC MCD 231804
TXZ000-232000-

MESOSCALE DISCUSSION 0782
NWS STORM PREDICTION CENTER NORMAN OK
0104 PM CDT THU MAY 23 2013

AREAS AFFECTED...PANHANDLE/NWRN TX

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 231804Z - 232000Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...TSTM INITIATION MAY OCCUR AS EARLY AS 19-20Z ALONG A
WWD-MOVING OUTFLOW BOUNDARY AND WEAK SURFACE CYCLONE NEAR AMA. VERY
STEEP LAPSE RATES...LARGE BUOYANCY AND SUFFICIENT DEEP-LAYER SHEAR
WILL EXIST FOR SUPERCELLS PRIMARILY PRODUCING VERY LARGE
HAIL...ALONG WITH A FEW TORNADOES AND ISOLATED SEVERE WINDS.

DISCUSSION...OUTFLOW BOUNDARY FROM DECAYING MCS ALONG THE RED RIVER
IN SERN OK/NERN TX CONTINUES TO MOVE WWD TO NEAR AMA SEWD ACROSS THE
LOW ROLLING PLAINS OF NWRN TX. SURFACE TEMPERATURES HAVE REACHED THE
LOWER 90S SW OF THIS BOUNDARY. MODIFIED 12Z MAF RAOBS AND RECENT
ACARS DATA INVOF LBB SUGGEST INHIBITION WILL BECOME MINIMAL SOON.
WITH PERSISTENT CONVERGENCE ALONG THE BOUNDARY...CONVECTION-ALLOWING
MODEL GUIDANCE INDICATE INITIAL TSTM DEVELOPMENT WILL OCCUR BETWEEN
19-21Z.

ALTHOUGH MIXING WILL CONTINUE ALONG THE NWRN PERIPHERY OF THE RICH
GULF MOISTURE PLUME...RESULTING IN LOWERING SURFACE DEW
POINTS...VERY STEEP LAPSE RATES AND MLCAPE AOA 2500 J/KG WILL
PROMOTE RAPID SUPERCELL DEVELOPMENT ONCE INITIATION OCCURS. LARGE TO
GIANT HAIL IS QUITE LIKELY WHERE THIS OCCURS. TORNADO POTENTIAL
SHOULD BE MAXIMIZED ALONG AND NEAR THE COOL SIDE OF THE OUTFLOW
BOUNDARY WHERE LOW-LEVEL SRH WILL BE ENHANCED AND LCL HEIGHTS WILL
BE LOWER.

..GRAMS/KERR.. 05/23/2013

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

ATTN...WFO...OUN...SJT...LUB...AMA...MAF...

LAT...LON   34460191 35340196 35520183 35550151 35420117 34630020
            33879952 33449946 33009969 32780023 32790116 33360195
            34460191