Nov 16, 2011 1300 UTC Day 1 Convective Outlook
Updated: Wed Nov 16 13:04:11 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20111116 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20111116 1300 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Probabilistic Damaging Wind Graphic
20111116 1300 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Probabilistic Large Hail Graphic
20111116 1300 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
   SPC AC 161300
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0700 AM CST WED NOV 16 2011
   
   VALID 161300Z - 171200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LWR MS VLY/ERN GULF
   CST INTO THE CAROLINAS/MID ATLANTIC...
   
   ...SYNOPSIS...
   BROAD CYCLONIC FLOW OVER THE CONUS IN RECENT DAYS WILL AMPLIFY THIS
   PERIOD AS JET STREAKS NOW OVER AB...MT...AND WY SWEEP RAPIDLY
   SEWD...RESULTING IN A DEEP BUT PROGRESSIVE TROUGH OVER THE LWR OH
   VLY BY 12Z THU.  IN THE MEANTIME...UPR IMPULSE THAT CROSSED E TX
   YESTERDAY WILL CONTINUE TO BECOME ABSORBED WITHIN STRONG AND FURTHER
   STRENGTHENING SW FLOW OVER THE SERN STATES.  THE MAIN PART OF THAT
   DISTURBANCE IS OVER MS ATTM...AND SHOULD REACH PIEDMONT NC BY EARLY
   EVE AS A HIGH LVL JET ENTRANCE REGION DEVELOPS OVER THE MID ATLANTIC
   IN RESPONSE TO AMPLIFICATION OF LARGER SCALE TROUGH.
   
   AT THE SFC...SEASONABLY RICH MOISTURE /WITH SFC DEWPOINTS IN THE MID
   60S F AND PW AROUND 1.50 INCHES/...WILL CONTINUE TO STREAM NEWD
   ACROSS GA AND THE CAROLINAS TO VICINITY OF STNRY FRONT OVER VA.  SFC
   WAVE NOW OVER NRN MS/AL SHOULD REDEVELOP ENE ALONG THE FRONT INTO
   CNTRL VA LATER TODAY.  ADDITIONAL WEAK WAVES LIKELY WILL DEVELOP
   ALONG THE BOUNDARY UNTIL IT FINALLY CLEARS THE CAROLINA CST AS A
   COLD FRONT LATER THU MORNING.
   
   ...LWR MS VLY/ERN GULF CST INTO CAROLINAS/MID-ATLANTIC...
   BAND OF SCTD SUPERCELLS ALONG LOW LVL CONFLUENCE AXIS OVER SE LA/ERN
   MS AND WRN AL LIKELY WILL PERSIST FOR AT LEAST A WHILE LONGER THIS
   MORNING AS THE AXIS EDGES SLOWLY EWD IN RESPONSE TO EJECTING UPR
   IMPULSE.  COMBINATION OF RICH MOISTURE INFLOW AND STRONG LOW LVL
   SHEAR MAY CONTINUE TO FOSTER LOW LVL ROTATION/ISOLD TORNADOES AS THE
   FEATURES CROSSES AL /REF WWS 887 888/.
   
   WITH TIME...MODEST DIURNAL HEATING MAY FOSTER REJUVENATION OF THE
   CONFLUENCE AXIS STORMS.  MORE LIKELY...HOWEVER...HEATING WILL
   SUPPORT EVENTUAL ADDITIONAL DEVELOPMENT EAST OF THE CONFLUENCE AXIS
   OVER PARTS OF GA AND THE CAROLINAS...S AND E OF SHALLOW
   RAIN-REINFORCED BOUNDARY ALONG THE SRN SLOPES OF THE APPALACHIANS. 
   WEAKENING OF UPR IMPULSE IN CONFLUENT FLOW ALOFT SUGGESTS THAT LARGE
   SCALE FORCING FOR ASCENT WILL BE WEAK.  BUT COMBINATION OF EVEN WEAK
   DESTABILIZATION /SBCAPE TO 1000 J PER KG/ WITH STRONG VEERING WIND
   PROFILES /40 KT SW 850 MB FLOW BENEATH 60-70 KT WSW FLOW AT 500 MB/
   LIKELY WILL SUPPORT SUSTAINED STORMS/SUPERCELLS.  THESE MAY ORGANIZE
   INTO BROKEN BANDS THAT WILL POSE A RISK FOR BOTH TORNADOES AND
   NARROW SWATHS OF DMGG WIND...ESPECIALLY ACROSS APPALACHIAN
   FOOTHILLS/PIEDMONT OF GA AND THE CAROLINAS/VA.  ADDITIONAL CLUSTERS
   OF STORMS MAY FORM TNGT THROUGH EARLY THU CLOSER TO THE CST AS LARGE
   SCALE ASCENT INCREASES WITH THE DEVELOPMENT OF AFOREMENTIONED UPR
   LVL JET ENTRANCE REGION.
   
   FARTHER NW...OTHER TSTMS MAY PERSIST THROUGH THE PERIOD ALONG
   MERGING COLD FRONTS OVER THE TN VLY...BUT THIS ACTIVITY SHOULD
   REMAIN MARGINAL DUE TO WEAKER INSTABILITY.
   
   ..CORFIDI/ROGERS.. 11/16/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z