SPC AC 260054
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0754 PM CDT MON MAY 25 2009
VALID 260100Z - 261200Z
...NO SVR TSTM AREAS FORECAST...
...OK/TX PNHDLS INTO DEEP S TX...
SURFACE COLD FRONT FROM WRN KS SWWD THROUGH THE WRN OK PNHDL INTO
NERN NM AS OF 00Z WILL PROGRESS SWD THROUGH THE PNHDLS AND THE TX S
PLAINS BY 26/12Z. PRE-FRONTAL STORMS HAVE DEVELOPED THIS AFTERNOON
AND EVENING INVOF DRYLINE AND PRE-EXISTING OUTFLOW BOUNDARIES...
NAMELY ACROSS THE OK AND NRN TX PNHDLS. HIGH RESOLUTION RADAR AND
VISIBLE SATELLITE DATA INDICATE THAT CONSIDERABLE COLD POOL
GENERATION IS OCCURRING WITH THIS ACTIVITY WITH A NARROW AXIS OVER
THE CNTRL TX PNHDL REMAINING UNCONTAMINATED. MODIFICATION OF 00Z
AMA SOUNDING FOR SLIGHTLY HIGHER DEWPOINTS OBSERVED TO THE E WITHIN
THIS AXIS SUGGESTS THAT AIR MASS REMAINS MODERATELY UNSTABLE WITH
MLCAPE OF 1000-1500 J/KG.
UPSCALE GROWTH INTO LARGER TSTM CLUSTERS OR AN MCS STILL REMAINS
POSSIBLE TONIGHT OVER THE SRN TX PNHDL INTO NWRN TX/WRN OK AS
STRENGTHENING LLJ ENHANCES LOW-LEVEL CONVERGENCE ALONG MERGING
MESOSCALE COLD POOLS AND SYNOPTIC FRONT. LATEST OBSERVATIONAL DATA
INDICATE THAT DEEP-LAYER BULK SHEAR REMAINS QUITE MARGINAL /I.E.
GENERALLY LESS THAN 25-30 KT/ AND THIS WILL LIMIT THE POTENTIAL FOR
A MORE ORGANIZED CONVECTIVE SYSTEM. NONETHELESS...THE MORE INTENSE
STORMS WILL REMAIN CAPABLE OF LOCALLY STRONG WIND GUSTS AND SOME
HAIL.
FOR ADDITIONAL SHORT TERM GUIDANCE IN THIS AREA...SEE MCD 869.
FARTHER S...SCATTERED TSTMS HAVE DEVELOPED ALONG DRYLINE OVER THE
LOW ROLLING PLAINS INTO THE CONCHO VALLEY AND WRN PARTS OF THE
EDWARDS PLATEAU REGION. EVENING WATER VAPOR IMAGERY SUGGESTS THAT
FORCING FOR ASCENT ASSOCIATED WITH LOW LATITUDE IMPULSE TRANSLATING
ACROSS NWRN MEXICO MAY BE IN PART CONTRIBUTING TO THIS DEVELOPMENT.
00Z DRT SOUNDING INDICATES DEEPLY MIXED BOUNDARY LAYER CONDITIONS
WITH STEEP LAPSE RATES CONTRIBUTING TO MLCAPE OF AROUND 1000 J/KG.
THIS ENVIRONMENT WILL CONTINUE TO SUPPORT CLUSTERS OF STRONG TO
POTENTIALLY SEVERE STORMS FOR THE NEXT SEVERAL HOURS WITH THE THREAT
FOR HAIL AND STRONG WIND GUSTS. LATER TONIGHT...STRENGTHENING
CONVECTIVE INHIBITION SHOULD RESULT IN A DECREASE IN STORM COVERAGE
AND INTENSITY.
FINALLY OVER DEEP S TX...A TSTM HAS RECENTLY DEVELOPED S OF ALI
ALONG WWD-MOVING SEA BREEZE BOUNDARY. 00Z BRO SOUNDING IS LIKELY
QUITE REPRESENTIVE OF STORM PROXIMITY ENVIRONMENT WITH MARITIME
TROPICAL BOUNDARY LAYER AND STEEP MIDLEVEL LAPSE RATES CONTRIBUTING
TO MLCAPE AROUND 2000 J/KG. THIS INSTABILITY COMBINED WITH MODEST
MID AND HIGH-LEVEL FLOW SUGGESTS THE POTENTIAL FOR UPDRAFT ROTATION
WITH ABOVE-MENTIONED STORM OR ANY ACTIVITY MOVING ACROSS THE RIO
GRANDE. GIVEN THE PRESENCE OF THE RATHER STRONG CAP IN
PLACE...STORMS SHOULD BEGIN TO WEAKEN AFTER SUNSET AS THE BOUNDARY
LAYER BEGINS TO COOL.
..MEAD.. 05/26/2009
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
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