109 
 WTPZ42 KNHC 290855
 TCDEP2
  
 TROPICAL STORM BARBARA DISCUSSION NUMBER   3
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP022013
 200 AM PDT WED MAY 29 2013
  
 SATELLITE IMAGERY AND RADAR DATA FROM PUERTO ANGEL MEXICO INDICATE
 THAT THE STRUCTURE OF BARBARA HAS CONTINUED TO INCREASE IN
 ORGANIZATION OVERNIGHT.  THE CENTER IS EMBEDDED IN THE MIDDLE OF A
 CENTRAL DENSE OVERCAST...COMPRISED OF COLD-TOPPED DEEP CONVECTION.
 BANDING HAS INCREASED...WITH THE MOST PROMINENT BAND WRAPPING
 ALMOST ENTIRELY AROUND THE CIRCULATION.  MORE RECENTLY...A PARTIAL
 EYEWALL HAS BEEN NOTED IN RADAR IMAGERY...WITH THE EYEWALL BECOMING
 INCREASINGLY BETTER DEFINED.  DVORAK T-NUMBERS WERE 3.0 FROM TAFB
 AND 3.5 FROM SAB...AND THE INITIAL INTENSITY HAS THEREFORE BEEN
 RAISED TO 50 KT.
  
 THE INITIAL MOTION IS 035/04. BARBARA HAS BEEN MOVING SLOWLY
 NORTHEASTWARD AROUND THE NORTHWEST SIDE OF A MID-LEVEL RIDGE OVER
 THE WESTERN CARIBBEAN SEA. HOWEVER...THE APPROACH OF A TROUGH OVER
 THE CENTRAL UNITED STATES SHOULD DRAW THE CYCLONE NORTH-
 NORTHEASTWARD OR NORTHEASTWARD WITH SOME INCREASE IN FORWARD SPEED
 TODAY. THIS MOTION SHOULD BRING THE CENTER OF THE CYCLONE TO THE
 COAST IN THE GULF OF TEHUANTEPEC IN THE NEXT 12 TO 18 HOURS. AFTER
 CROSSING THE COAST...THE WEAKENING CYCLONE SHOULD MOVE NEAR OR WEST
 OF THE ISTHMUS OF TEHUANTEPEC BEFORE DISSIPATING...WITH AN OUTSIDE
 CHANCE OF THE REMNANTS ENTERING THE BAY OF CAMPECHE. THE NHC TRACK
 FORECAST REPRESENTS AN UPDATE OF THE PREVIOUS ONE AND IS CLOSE TO
 THE GFS AND MULTI-MODEL CONSENSUS.
  
 SHEAR ANALYSES FROM UW-CIMSS AND SHIPS MODEL SHOW ONLY LIGHT SHEAR
 OVER BARBARA AS IT MOVES SLOWLY OVER VERY WARM SSTS AROUND 30C. 
 THESE FAVORABLE ENVIRONMENTAL FACTORS ARE EXPECTED TO REMAIN IN
 PLACE PRIOR TO LANDFALL.  IN ADDITION...AN EARLIER SSMI/S PASS
 SHOWED A CLOSED LOW-LEVEL RING OF CONVECTION...POSSIBLY A HARBINGER
 OF A RAPID INTENSIFICATION PHASE ABOUT TO OCCUR. THE LACK OF TIME
 OVER WATER IS THE MAIN LIMITING FACTOR FOR SIGNIFICANT
 STRENGTHENING. THE NEW NHC INTENSITY FORECAST IS INCREASED FROM THE
 PREVIOUS ONE IN THE FIRST 12 HOURS GIVEN CURRENT TRENDS...AND IS
 CLOSE TO THE SHIPS/LGEM GUIDANCE AND WELL AS THE INTENSITY
 CONSENSUS AIDS.
  
 ALTHOUGH NOT EXPLICITLY FORECAST...THERE IS A POSSIBILITY THAT
 BARBARA COULD REACH HURRICANE STRENGTH PRIOR TO LANDFALL.  FOR THIS
 REASON...THE GOVERNMENT OF MEXICO HAS ISSUED A HURRICANE WATCH FOR
 A PORTION OF THE COAST OF THE GULF OF TEHUANTEPEC.
  
 DUE TO THE SLOW MOTION OF THIS SYSTEM...AS WELL AS THE MOUNTAINOUS
 TERRAIN IN AND NEAR THE LANDFALL AREA...HEAVY RAINFALL IS EXPECTED
 OVER PORTIONS OF SOUTHEASTERN MEXICO...WHICH COULD RESULT IN
 LIFE-THREATENING FLASH FLOODS AND MUD SLIDES.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  29/0900Z 14.8N  95.6W   50 KT  60 MPH
  12H  29/1800Z 15.7N  95.0W   60 KT  70 MPH
  24H  30/0600Z 17.0N  94.8W   40 KT  45 MPH...INLAND
  36H  30/1800Z 18.0N  94.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
  48H  31/0600Z...DISSIPATED
  
 $$
 FORECASTER KIMBERLAIN/BROWN