Huh? Why do you ask??
PDS Tornado Watch to be issued soon for OK:
MESOSCALE DISCUSSION 0907
NWS STORM PREDICTION CENTER NORMAN OK
0240 PM CDT FRI MAY 31 2013
AREAS AFFECTED...MOST OF OK
CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY
VALID 311940Z - 312115Z
PROBABILITY OF WATCH ISSUANCE...95 PERCENT
SUMMARY...PDS TORNADO WATCH WILL BE ISSUED BY 21Z. ISOLATED TO
SCATTERED DISCRETE SUPERCELLS SHOULD FORM ALONG DRYLINE BETWEEN
21-23Z WITH PRIMARY INITIAL THREAT OF VERY LARGE HAIL AND ISOLATED
SEVERE WINDS. TORNADO RISK WILL INCREASE TOWARDS 00Z WITH AN
EXPECTATION OF A FEW SIGNIFICANT TORNADOES.
DISCUSSION...19Z SURFACE ANALYSIS PLACED A QUASI-STATIONARY FRONT
FROM GRANT TO CUSTER COUNTIES WITH A DRYLINE DRAPED S/SWWD INTO THE
LOW ROLLING PLAINS OF NWRN TX. SURFACE TEMPERATURES HAVE NOW
BREACHED 100 DEG F ALONG THE RED RIVER IN SWRN OK/NWRN
TX...RESULTING IN MINIMAL MLCIN PER MODIFIED 18Z OUN RAOB. CU JUST
AHEAD OF THE DRYLINE HAS BECOME MORE AGITATED IN LATEST VISIBLE
SATELLITE IMAGERY AND SHOULD CONTINUE TO GROW WITH GLANCING
INFLUENCE OF A SHORTWAVE IMPULSE OVER THE CNTRL HIGH PLAINS. THIS
SHOULD RESULT IN TSTM INITIATION BY 21Z.
STRONG EFFECTIVE SHEAR WILL PROMOTE SUPERCELLS WITH AN INITIAL
PRIMARY RISK OF VERY LARGE HAIL. WITH A PLUME OF 73-74 DEG F SURFACE
DEW POINTS REMAINING ACROSS CNTRL OK BENEATH THE CAPPING INVERSION
NOTED IN 18Z OUN RAOB...AND AS THE LLJ INTENSIFIES BY 00Z...TORNADO
THREAT WILL INCREASE SUBSTANTIALLY. SOME OF THESE WILL LIKELY BE
SIGNIFICANT...ESPECIALLY ALONG THE I-35 CORRIDOR.