000 WTPZ44 KNHC 150832 TCDEP4 HURRICANE CARLOS DISCUSSION NUMBER 22 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP042009 200 AM PDT WED JUL 15 2009 CARLOS REMAINS A COMPACT ANNULAR HURRICANE WITH A LACK OF DEEP CONVECTIVE FEATURES OUTSIDE OF A NEARLY UNIFORM RING OF DEEP CONVECTION SURROUNDING A 10 NM EYE. RECENT INFRARED IMAGES... HOWEVER...INDICATE THAT CLOUD TOP TEMPERATURES WITHIN THIS RING HAVE WARMED...HAVE BECOME SLIGHTLY LESS SYMMETRIC...AND HAVE SHRUNK IN SIZE. IN SPITE OF THIS...DVORAK T-NUMBERS OF 5.0 FROM BOTH SAB AND TAFB SUPPORT AND INITIAL INTENSITY OF 90 KT FOR THIS ADVISORY. SHIPS MODEL GUIDANCE INDICATES THAT WESTERLY DEEP-LAYER SHEAR SHOULD NOT CHANGE APPRECIABLY IN MAGNITUDE OVER CARLOS DURING THE NEXT 48 HOURS AND MAY EVEN DECREASE TEMPORARILY AROUND 24-36 HOURS. THIS DECREASE IN SHEAR SEEMS TO BE IN RESPONSE TO AN UPPER-LEVEL SHORTWAVE TROUGH SWEEPING BY TO THE NORTH OF THE CYCLONE. FOR THIS REASON...THE OFFICIAL FORECAST CALLS FOR A SUBTLE SHORT-TERM DECREASE IN INTENSITY IN LINE WITH SHIPS MODEL AND ICON INTENSITY CONSENSUS GUIDANCE. THEREAFTER...INCREASING WESTERLY FLOW ALOFT ASSOCIATED WITH AN ENHANCED MID-OCEAN TROUGH...COUPLED WITH THE SMALL SIZE OF CARLOS...SHOULD INDUCE A FASTER RATE OF WEAKENING. GIVEN THE RECENT POOR PERFORMANCE OF INTENSITY GUIDANCE...THE CURRENT INTENSITY FORECAST REMAINS OF LOW CONFIDENCE. RECENT SATELLITE FIXES YIELD AN INITIAL MOTION ESTIMATE OF 280/5... WHICH REPRESENTS A GRADUAL SLOWING OF THE FORWARD MOTION DURING THE LAST 24 HOURS. GIVEN CURRENT TRENDS...THE OFFICIAL FORECAST TRACK INITIALLY PERSISTS THE SLOWER MOTION AND LAGS MOST OF THE DYNAMICAL MODELS. AS CARLOS BEGINS TO WEAKEN LATER IN THE FORECAST PERIOD... THE OFFICIAL FORECAST INDICATES AN ACCELERATION IN FORWARD SPEED AS THE CYCLONE IS STEERED BY AN ENHANCED LOWER-TROPOSPHERIC FLOW. THE CURRENT FORECAST TRACK ESSENTIALLY REPRESENTS AN UPDATE OF THE PREVIOUS ADVISORY. OF NOTE...WITH AN INTENSITY OF 90 KT...CARLOS HAS BECOME THE STRONGEST HURRICANE SO FAR SOUTH IN THE EASTERN NORTH PACIFIC SINCE RELIABLE DATA RECORDS BEGAN IN 1966. FORECAST POSITIONS AND MAX WINDS INITIAL 15/0900Z 10.2N 129.0W 90 KT 12HR VT 15/1800Z 10.3N 130.0W 85 KT 24HR VT 16/0600Z 10.7N 131.5W 80 KT 36HR VT 16/1800Z 11.0N 133.4W 75 KT 48HR VT 17/0600Z 11.4N 135.4W 70 KT 72HR VT 18/0600Z 11.9N 140.5W 60 KT 96HR VT 19/0600Z 12.0N 146.5W 50 KT 120HR VT 20/0600Z 12.0N 153.0W 45 KT $$ FORECASTER KIMBERLAIN/AVILA