SPC AC 211738
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1138 AM CST MON FEB 21 2005
   
   VALID 221200Z - 231200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 E
   PSX 25 S SAT 55 NE DRT 35 WSW SJT 45 NNE BGS 25 ESE PVW 40 W CDS 40
   SE CDS 40 NNW MWL 15 ESE DAL 10 ENE GGG 40 SW MLU 35 SW JAN 25 ENE
   LUL 35 S SEM 15 S TOI 30 WSW DHN 30 ESE PNS.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 80 SW P07 25 SSE FST
   35 NW HOB 60 N ROW 35 N 4CR 35 ENE TCS 45 SE DMN ...CONT... 35 NW
   SFO MER 25 E BIH 35 NW ELY 50 N PUC 40 ENE GJT 30 E RTN 45 ENE GAG
   40 NW HOT 30 SSE UOX 15 WNW AND 45 ESE ECG ...CONT... 35 N DAB 20 SW
   CTY.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF TX ACROSS THE NRN
   GULF COAST AND LOWER MS VALLEY...
   
   ...SYNOPSIS...
   ACTIVE SPLIT FLOW PATTERN EXPECTED TO CONTINUE ON TUESDAY AS DEEP
   BAROCLINIC ZONE...SITUATED BENEATH FAST MID LEVEL FLOW...SINKS
   GRADUALLY SWD INTO INCREASINGLY WARM AND MOIST AIR MASS FROM NRN
   TX/TXK AREA ESEWD TO THE LWR MS VLY. FARTHER WEST...DEEP UPPER
   LOW...AND ASSOCIATED STRONGLY DIFFLUENT DOWNSTREAM FLOW...WILL MOVE
   SLOWLY EAST ACROSS SRN CA AND THE LWR CO RIVER VLY.
   
   ...NERN TX ACROSS NRN GULF COAST...
   MODEST ISENTROPIC LIFT WILL PERSIST ACROSS FRONTAL ZONE SAGGING SWD
   TOWARD N TX AND THE TXK AREA THROUGH LATE TONIGHT. WITH PLUME OF
   STEEP LAPSE RATES ATOP RETURNING GULF AIRMASS ACROSS THE REGION...
   AND PRESENCE OF LOW AMPLITUDE DISTURBANCES WITHIN FAST SUB-TROPICAL
   JET STREAM...MODELS APPEAR REASONABLE IN DEVELOPING A SMALL ELEVATED
   MCS TOWARD DAYBREAK TUESDAY ALONG AND EAST OF SEP-DFW LINE. IF THIS
   SYSTEM CAN UNDERGO UPSCALE DEVELOPMENT WITH THE AID OF UPPER
   DYNAMICS/WEAK HEIGHT FALLS...AND FORCING ALONG THE LOW LEVEL
   BOUNDARY FROM NEAR SHV TO LWR MS VALLEY...EXPECT THE POTENTIAL FOR
   SEVERE STORMS TO INCREASE THROUGH THE AFTERNOON AS GREATER
   SURFACE-BASED INSTABILITY IS TAPPED ACROSS THESE AREAS. DEEP WLY
   FLOW WITH INCREASING VERTICAL SPEED SHEAR WOULD APPEAR TO FAVOR A
   FAST MOVING SQUALL LINE WITH WIND AND HAIL MOVING FROM LA ACROSS SRN
   MS/AL THROUGH EVENING.
   
   ...WCNTRL/CNTRL TX...
   IN THE WAKE OF EARLY ELEVATED AND ISOLD STORMS MENTIONED
   ABOVE...WARM SECTOR AIR MASS ACROSS MUCH OF CNTRL/WCNTRL TX WILL
   BECOME MODERATELY UNSTABLE BY AFTERNOON WITH UPR 50S TO LWR 60S F
   DEWPOINTS AND TEMPERATURES IN THE 70S F CONTRIBUTING TO MLCAPE AOA
   1000 J/KG. LARGE SCALE FORCING FOR ASCENT APPEARS SUBTLE WITH REGION
   GENERALLY BENEATH BROAD MID LEVEL RIDGING. HOWEVER...WEAK MID LEVEL
   HEIGHT FALLS AND DISTURBANCES WITHIN SUB-TROPICAL JET...COUPLED WITH
   ELIMINATION OF CONVECTIVE INHIBITION FROM DIURNAL HEATING...SHOULD
   AID SURFACE-BASED TSTM INITIATION. WEAK LOW LEVEL FLOW...TOPPED BY
   35-40KT WLY FLOW IN MID LEVELS...SHOULD RESULT IN SHEAR PROFILES
   FAVORABLE FOR SUPERCELLS. A FEW LARGE HAIL REPORTS AND POSSIBLY
   DAMAGING WINDS COULD RESULT FROM THIS ACTIVITY.
   
   ...SRN CA/AZ...
   COLD AIR ALOFT AND STRONG DYNAMIC LIFT ON THE CYCLONIC SHEAR SIDE OF
   MID/UPPER JET WILL AGAIN SET THE STAGE FOR ISOLD STRONG CONVECTION
   ACROSS PARTS OF SRN CA AND THE LWR CO RIVER VALLEY. NUMEROUS
   IMPULSES WRAPPING AROUND THE LARGE UPPER LOW WILL AID STORM COVERAGE
   AND ORGANIZATION. PRIMARY UNCERTAINTY...AS IS USUALLY THE CASE OVER
   THE REGION...WILL CONTINUE TO BE DEGREE OF DESTABILIZATION. CLOUD
   COVER AND MARGINAL LOW LEVEL THETA-E USUALLY LEAD TO LIMITED CAPE.
   HOWEVER...REGION WILL NEED TO BE MONITORED CLOSELY FOR THE
   DEVELOPMENT OF POCKETS OF GREATER INSTABILITY DURING THE DAY. AN
   UPGRADE TO SLGT RISK IS CERTAINLY POSSIBLE IF STRONGER INSTABILITY
   CAN DEVELOP AND PROMOTE AN INCREASE IN THE PROBABILITY OF
   TORNADOES/DAMAGING WINDS AND HAIL.
   
   ..CARBIN.. 02/21/2005
   
   ...NOTICE...
   FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
   LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
   GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
   HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
   INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
   
   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0800Z