Apr 27, 2015 0600 UTC Day 1 Convective Outlook

DAY 1 CONVECTIVE OUTLOOK  

   NWS STORM PREDICTION CENTER NORMAN OK
   1154 PM CDT SUN APR 26 2015

   VALID 271200Z - 281200Z

   ...THERE IS AN ENH RISK OF SVR TSTMS FOR SRN LA...

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM EAST TX TO LA AND SRN
   MS/AL...

   ...THERE IS A MRGL RISK OF SVR TSTMS FOR MUCH OF E TX TO THE CNTRL
   GULF COAST...

   ...THERE IS A MRGL RISK OF SVR TSTMS FOR PARTS OF SOUTH FL...

   ...SUMMARY...
   SCATTERED SEVERE THUNDERSTORMS WILL DEVELOP ACROSS PARTS OF
   LOUISIANA THIS MORNING AND AFTERNOON. ADDITIONAL STRONG TO SEVERE
   THUNDERSTORMS ARE POSSIBLE OVER EAST TEXAS...WHILE ISOLATED STRONG
   STORMS ARE POSSIBLE OVER SOUTH FLORIDA.

   ...SYNOPSIS...
   A SRN STREAM CLOSED LOW-MIDLEVEL CYCLONE WILL SLOWLY MOVE EWD ACROSS
   THE SRN PLAINS. AN ATTENDANT UPPER JET WILL EXTEND FROM S TX ACROSS
   THE CNTRL GULF COAST. AT THE SFC...WEAK LOW PRESSURE WILL DEVELOP
   OVER E TX. SEGMENT OF A COLD FRONT WILL BECOME QUASISTATIONARY
   ACROSS THE SOUTHEAST...KEEPING A MARITIME TROPICAL AIR MASS CONFINED
   TO NEAR THE GULF COAST. 

   ...E TX INTO THE CNTRL GULF COAST...
   AN MCS SHOULD BE ONGOING EARLY MON MORNING NEAR THE SABINE VALLEY
   INTO WRN LA. THIS FEATURE IS EXPECTED TO CONTINUE PROGRESSING EWD
   ACROSS THE CNTRL GULF COAST STATES THROUGH LATE MORNING...WITH AN
   ACCOMPANYING DMGG WIND AND ISOLATED TORNADO RISK
   POSSIBLE...ESPECIALLY ALONG/S OF A QUASI-STATIONARY BAROCLINIC ZONE
   ORIENTED GENERALLY W-E. 27/00Z LIX SOUNDING AND SFC OBS SAMPLED RICH
   LOW-LEVEL MOISTURE AND STEEP MIDLEVEL LAPSE RATES IN PLACE...AND
   MLCAPE VALUES SHOULD REACH 1000-1500 J/KG AHEAD OF THE QLCS.
   HERE...TSTMS MAY ALSO DEVELOP INVOF THE BAROCLINIC ZONE AMIDST WEAK
   LOW-LEVEL WAA...AND AN ISOLATED TORNADO THREAT CANNOT BE RULED OUT.

   MEANWHILE...AIR MASS RECOVERY SHOULD OCCUR ACROSS E TX INTO SWRN LA
   IN THE WAKE OF MORNING CONVECTION...ALTHOUGH TO WHAT DEGREE IT CAN
   DESTABILIZE GIVEN THE PRESENCE OF CLOUD COVER REMAINS UNCERTAIN.
   HOWEVER...MOST MODEL GUIDANCE SUGGESTS A NARROW CORRIDOR OF MODERATE
   INSTABILITY WILL EXIST /ROUGHLY FROM HOUSTON TO DALLAS/ IN
   CONJUNCTION WITH DEWPOINTS IN THE 60S E OF A WEAK SFC LOW AND
   ATTENDANT PACIFIC FRONT. VERTICAL WIND PROFILES WOULD BE SUFFICIENT
   FOR SUPERCELLS...BUT CONVECTIVE INITIATION/EVOLUTION WILL BE
   DEPENDENT ON PRESENCE/POSITION OF OUTFLOW BOUNDARIES...AND WHETHER
   ENOUGH HEATING CAN OCCUR TO OVERCOME CINH AND SUPPORT SFC-BASED
   CONVECTION. SCATTERED TSTMS MAY CONTINUE INTO THE LATE EVENING
   ACROSS THE SABINE VALLEY AND ACROSS LA/SRN MS.

   ...SOUTH FL...
   AFTERNOON SEA BREEZE TSTMS ARE FORECAST TO DEVELOP OVER SOUTH FL
   AMIDST VERY WARM DAYTIME TEMPERATURES IN THE 90S. ALTHOUGH LOW-LEVEL
   FLOW WILL BE WEAK...30-40 KT OF MIDLEVEL WLYS COULD SUPPORT
   MARGINALLY ORGANIZED CONVECTION CAPABLE OF PRODUCING LOCALIZED
   STRONG WIND GUSTS AND HAIL.