753 
 WTPZ42 KNHC 291438
 TCDEP2
  
 TROPICAL STORM BARBARA DISCUSSION NUMBER   5
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP022013
 800 AM PDT WED MAY 29 2013
  
 AFTER A SIGNIFICANT INTENSIFICATION EPISODE EARLIER THIS
 MORNING...RADAR AND SATELLITE DATA SHOW LITTLE CHANGE IN
 ORGANIZATION OVER THE PAST FEW HOURS.  RADAR IMAGERY SUGGESTS A
 BANDING-TYPE EYE AS OPPOSED TO A CLOSED EYEWALL.  BASED ON A
 COMPARISON OF VISIBLE SATELLITE IMAGERY TO THE PUERTO ANGEL MEXICAN
 RADAR IMAGES...THE CENTER IS TILTED SLIGHTLY SOUTHWARD WITH HEIGHT. 
 THIS IS CONSISTENT WITH THE MODERATE NORTHERLY VERTICAL SHEAR
 DIAGNOSED BY THE NUMERICAL GUIDANCE.  THE CURRENT INTENSITY IS SET
 AT 55 KT IN AGREEMENT WITH THE LATEST OBJECTIVE DVORAK ESTIMATES.
 THE WINDOW FOR INTENSIFICATION PRIOR TO LANDFALL IS CLOSING...BUT
 ENVIRONMENTAL CONDITIONS CONTINUE TO FAVOR STRENGTHENING UNTIL THE
 CENTER CROSSES THE COASTLINE. ALTHOUGH NOT EXPLICITLY SHOWN IN THE
 WIND SPEED FORECAST...WE STILL ANTICIPATE THAT BARBARA WILL BECOME
 A HURRICANE IN A FEW HOURS. WEAKENING SHOULD BE RAPID LATER TODAY
 AND TONIGHT AS THE CYCLONE INTERACTS WITH THE MOUNTAINOUS TERRAIN
 OF SOUTHEASTERN MEXICO. ALTHOUGH THE CENTER IS FORECAST TO REACH
 THE EXTREME SOUTHWEST GULF OF MEXICO WITHIN 36 HOURS...THE CURRENT
 THINKING IS THAT THE CIRCULATION WILL HAVE BEEN SO SEVERELY
 DISRUPTED BY THAT TIME THAT REGENERATION IS UNLIKELY. THIS IS
 SUPPORTED BY THE GLOBAL MODELS...WHICH ALSO SHOW STRONG VERTICAL
 SHEAR OVER THE SOUTHWEST GULF.
  
 THE FORWARD SPEED HAS INCREASED SUBSTANTIALLY THIS MORNING AND THE
 INITIAL MOTION ESTIMATE IS 040/11. THE ACCELERATION APPEARS TO BE
 DUE TO A BELT OF MID-LEVEL SOUTHWESTERLIES THAT EXTENDS FROM THE
 LOW LATITUDES OF THE EASTERN PACIFIC INTO EXTREME EASTERN MEXICO
 AND CENTRAL AMERICA. WHEN THE CYCLONE MOVES OVER THE ISTHMUS OF
 TEHUANTEPEC...IT SHOULD ENCOUNTER A WEAKER STEERING CURRENT AS IT
 MOVES AWAY FROM THE BELT OF SOUTHWESTERLIES AND APPROACHES A BROAD
 RIDGE OVER CENTRAL MEXICO. THE OFFICIAL FORECAST SHOWS A DECREASING
 FORWARD SPEED OVER THE NEXT DAY OR SO...WHICH IS IN GOOD AGREEMENT
 WITH THE TRACK MODEL CONSENSUS.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  29/1500Z 15.7N  94.6W   55 KT  65 MPH
  12H  30/0000Z 16.9N  94.0W   40 KT  45 MPH...INLAND
  24H  30/1200Z 17.9N  93.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
  36H  31/0000Z 18.5N  94.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
  48H  31/1200Z...DISSIPATED
  
 $$
 FORECASTER PASCH/LANDSEA