Mesoscale Discussion 715

MESOSCALE DISCUSSION 0715
NWS STORM PREDICTION CENTER NORMAN OK
0415 PM CDT THU APR 24 2008
AREAS AFFECTED...CENTRAL/WRN OK...NWRN TX
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 242115Z - 242345Z
CUMULUS DEVELOPMENT ALONG THE DRYLINE IS INDICATIVE OF WEAKENING
CINH. A WATCH MAY BE NEEDED IN THE NEXT COUPLE OF HOURS IF DEEPER
CONVECTIVE DEVELOPMENT IS NOTED.
LATEST SFC ANALYSIS SHOWS VERY WARM TEMPERATURES /LOWER-MID 90S/ IN
THE WAKE OF A DRYLINE THAT EXTENDS FROM WRN WOODS COUNTY SWD TO JUST
WEST OF FSI TO HASKELL COUNTY TEXAS. 19Z OUN SOUNDING SHOWED LITTLE
REMAINING CINH BASED ON A SFC-BASED PARCEL OF 89/64 DEG F. A FEW
MESONET SITES IN SCENTRAL OK INDICATE CONDITIONS NEAR THIS WHERE
OBJECTIVE ANALYSIS SHOWS LESS THAN 25 J/KG OF MLCINH AT 21Z.
ATTM...THE GREATEST NEGATIVES TOWARDS TSTM INITIATION OVER
CENTRAL/WRN OK IS THE LIMITED CONVERGENCE ALONG THE DRYLINE AND
LARGE SCALE SUBSIDENCE IN THE WAKE OF AN EARLIER SHORTWAVE TROUGH.
RECENT WV IMAGERY SHOWS THE LEADING EDGE OF SYNOPTIC SCALE VERTICAL
MOTION WAS STILL OVER THE WRN TX PANHANDLE/SWRN KS. SEVERAL MORE
HOURS OF DOWNWARD OR NEUTRAL VERTICAL MOTION WILL CONTINUE...WITH
CONVECTIVE INITIATION HIGHLY UNCERTAIN AS LIMITED VERTICAL MOTION IS
EXPECTED TO OCCUR ALONG/AHEAD OF THE DRYLINE PRIOR TO LOSS OF
DAYTIME HEATING. IF ANY TSTM DOES DEVELOP DUE TO PRIMARILY SFC
CONVERGENCE AHEAD OF THE DRYLINE...MODERATE INSTABILITY /MLCAPE
AROUND 2500 J/KG/ WILL COMBINE WITH MODERATE VERTICAL SHEAR /35-40
KTS/ TO SUPPORT SUPERCELL-TYPE TSTMS CAPABLE OF LARGE HAIL/DMGG
WINDS.
..CROSBIE.. 04/24/2008