Mesoscale Discussion 651

MESOSCALE DISCUSSION 0651
NWS STORM PREDICTION CENTER NORMAN OK
0130 PM CDT THU APR 17 2008
AREAS AFFECTED...CNTRL/ECNTRL OK AND NCNTRL TX
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 171830Z - 172100Z
A BAND OF TSTMS IS EXPECTED TO DEVELOP ACROSS CNTRL OK AND NCNTRL TX
BETWEEN 21-00Z. LARGE HAIL AND DMGG WIND GUSTS MAY OCCUR AND A
WEATHER WATCH MAY BE REQUIRED.
MID-AFTN WATER VAPOR IMAGERY DEPICTS AN UPR LOW OVER NM. THIS
FEATURE WILL MOVE ENEWD INTO THE SRN PLAINS THIS EVE WITH ATTENDANT
SFC LOW MIGRATING FROM CNTRL OK INTO ERN KS BY EARLY EVENING. 18Z
SFC COLD FRONT EXTENDING FROM ENID-LAWTON-JUST N OF MIDLAND WILL
CONTINUE EWD REACHING A STILLWATER-ARDMORE-MINERAL WELLS LINE BY
00Z. THE FRONT WILL BE THE FOCUS FOR POSSIBLE SVR TSTMS LATER THIS
AFTN.
PRE-FRONTAL AIR MASS WAS STILL WELL-CAPPED...BUT WAS GRADUALLY
MOISTENING. WIDESPREAD STRATOCUMULUS HAS MITIGATED HEATING THROUGH
EARLY AFTN. RECENTLY...HOWEVER...VISIBLE SATL SHOWS THINNING OF THE
CLOUD COVER AND THIS SHOULD RESULT IN AN INCREASE IN THERMAL
BUOYANCY THROUGH THE LATE AFTN HOURS. AT THE SAME TIME...COOLING
ALOFT WILL COMMENCE AS THE UPR LOW APPROACHES THE REGION. WEAKENING
INHIBITION AND PERSISTENT/DEEPENING FRONTAL CIRCULATION WILL
SUBSEQUENTLY RESULT IN CONVECTIVE INITIATION VERY NEAR/JUST WEST OF
THE I-35 CORRIDOR SWWD INTO NCNTRL TX IN THE 21-00Z TIME FRAME.
BACKING DEEP LAYER PROFILE WILL RESULT IN RAPID EVOLUTION INTO LINES
AND TSTMS WILL TEND TO BE UNDERCUT BY THE SURGING COLD FRONT.
NONETHELESS..STEEP MID-TROPOSPHERIC LAPSE RATES AND 50-60 KTS OF
EFFECTIVE BULK SHEAR WILL FAVOR ORGANIZED STORMS WITH LARGE HAIL.
IF STORMS DEVELOP SUFFICIENTLY CLOSE TO THE FRONTAL INTERFACE...DMGG
WIND GUSTS COULD ALSO OCCUR.
ACTIVITY WILL BACKBUILD SWWD WITH TIME INTO AREAS W OF THE
DALLAS-FORT WORTH METROPLEX BEYOND 00Z.
..RACY.. 04/17/2008