SPC AC 160728
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0228 AM CDT WED JUL 16 2008
   
   VALID 181200Z - 191200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE NRN HIGH PLAINS...
   
   ...SYNOPSIS...
   WLYS WILL UNDERGO A SLIGHT AMPLIFICATION BY WEEK'S END AS A NRN
   POLAR BRANCH TROUGH DIGS THROUGH SW CANADA AND PHASES WITH THE SRN
   BRANCH OVER THE NRN INTERMOUNTAIN WEST.  LARGE SCALE HEIGHT FALLS
   THEN ARE EXPECTED TO SPREAD INTO THE NRN PLAINS BY 12Z SATURDAY. 
   DOWNSTREAM...A LEAD IMPULSE WILL LIKELY TRAVEL FROM CNTRL GRTLKS
   ACROSS NEW ENGLAND WITH A LOWER AMPLITUDE SUB-TROPICAL WAVE MOVING
   THROUGH THE CNTRL PLAINS TO THE UPR MS VLY BY FRIDAY NIGHT.
   
   IN THE LWR LVLS...WAVY FRONT WILL CONTINUE FROM CNTRL/NRN ENGLAND
   WWD INTO THE UPR MS VLY.  WRN END OF THE FRONT...AUGMENTED BY
   OUTFLOW FROM PREVIOUS DAY TSTMS...WILL ARC FROM THE CORN BELT ACROSS
   THE CNTRL PLAINS...THEN NWWD INTO THE NRN HIGH PLAINS.  A NEW FRONT
   WILL BEGIN TO SWEEP SEWD FROM THE NRN INTERMOUNTAIN W INTO THE NRN
   HIGH PLAINS LATE IN THE PD.
   
   ...NRN HIGH PLAINS...
   MOISTURE IS APT TO CONTINUE INCREASING OVER MID-WEEK VALUES AS 
   LOW-LVL WINDS BEGIN RESPONDING TO THE DIGGING POLAR STREAM IMPULSE. 
   FAVORABLE TIMING OF THE TROUGH WILL INITIATE HIGH-BASED STORMS IN
   THE MOUNTAINS EARLY IN THE AFTN.  AS HEATING ERODES LOWER-ELEVATION
   CINH...STORMS WILL LIKELY BECOME STRONGER AS THEY MOVE ONTO THE
   PLAINS WHERE MLCAPES COULD REACH 1500-2000 J/KG.  BULK SHEAR OF
   40-45 KTS WILL BE FAVORABLE FOR SUPERCELLS WITH LARGE HAIL
   INITIALLY.  ACTIVITY WILL TEND TO DEVELOP ESE TOWARD SW ND AND WRN
   SD OVERNIGHT WITH DMGG WINDS AN ADDED THREAT.
   
   ...CNTRL PLAINS TO THE UPR MS VLY...
   SUB-TROPICAL DISTURBANCE WILL MIGRATE ENE INTO THE UPR MS VLY DURING
   THE PROGRESS OF THE DAY.  ASSOCD MID-LVL SPEED MAX WILL ENRICH
   VERTICAL SHEAR VALUES ALONG THE TRACK OF THIS SYSTEM.  BUT...GIVEN
   SEVERAL EPISODIC TSTM EVENTS LEADING UP TO FRIDAY OVER THIS REGION
   AND THE FACT THAT A MORE TROPICAL MID-LVL LAPSE RATE ENVELOPE WILL
   BE INFUSED INTO THE ENVIRONMENT...SET-UP APPEARS MORE FAVORABLE FOR
   HEAVY RAINFALL THAN SVR STORMS.  NONETHELESS...TSTMS THAT WILL FORM
   ALONG THE FRONT FROM NCNTRL KS AND SERN NEB NEWD INTO CNTRL WI WILL
   LIKELY TAKE ADVANTAGE OF MODEST INSTABILITY WITH ISOLD DMGG WIND
   GUSTS POSSIBLE.
   
   ...CNTRL/NRN NEW ENGLAND...
   A 50 KT MID-LVL SPEED MAX ASSOCD WITH THE AFOREMENTIONED LEAD WAVE
   WILL MOVE ACROSS THE AREA DURING PEAK HEATING.  LOW-LEVELS WILL HAVE
   MOISTENED SUBSTANTIALLY INVOF THE FRONT BY FRIDAY
   AFTN...CONTRIBUTING TO MODEST INSTABILITY.  ISOLD TSTMS WILL
   PROBABLY DEVELOP INVOF THE FRONT DURING THE AFTN...AND GIVEN
   EFFECTIVE SHEAR OF 45-50 KTS...ISOLD STORMS COULD BECOME SVR WITH
   LARGE HAIL AND DMGG WIND GUSTS.
   
   ..RACY.. 07/16/2008
   
   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1100Z