649 
 WTNT45 KNHC 070848
 TCDAT5
 TROPICAL STORM HENRI DISCUSSION NUMBER   3
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL102009
 500 AM AST WED OCT 07 2009
  
 INFRARED SATELLITE IMAGERY AFTER THE ECLIPSE SHOWS A LARGE MASS OF
 VIGOROUS DEEP CONVECTION ASSOCIATED WITH HENRI...WITH CLOUD TOP
 TEMPERATURES COLDER THAN -80C. IN FACT...THE AREAL COVERAGE OF DEEP
 CONVECTION HAS EXPANDED CONSIDERABLY SINCE YESTERDAY EVENING...
 THOUGH THERE ARE NO BANDING FEATURES. HOWEVER...A 0531 UTC AMSR-E
 PASS INDICATED THAT THE CENTER WAS STILL PARTIALLY EXPOSED...
 LOCATED ON THE WESTERN EDGE OF THE MAIN CONVECTIVE CLUSTER. BASED
 UPON THE IMPROVEMENT IN ORGANIZATION DURING THE PAST SEVERAL
 HOURS...THE INITIAL INTENSITY IS RAISED TO 45 KT IN ACCORDANCE WITH
 0600 UTC DVORAK CLASSIFICATIONS OF 3.0 FROM TAFB AND RECENT
 OBJECTIVE ESTIMATES NEAR 3.0 FROM UW CIMSS.
  
 PERSISTENT SOUTHWESTERLY SHEAR OF 20-25 KT CONTINUES TO PREVENT
 HENRI FROM STRENGTHENING MUCH. SHIPS MODEL GUIDANCE INDICATES THAT
 HIGH WESTERLY SHEAR SHOULD PREVAIL OVER HENRI FOR AT LEAST THE NEXT
 24 HOURS...WITH A POSSIBLE RELAXATION THEREAFTER. THIS DOES NOT
 SEEM ENTIRELY REALISTIC...AS A MAJORITY OF GLOBAL MODELS INDICATE
 THAT HENRI SHOULD CROSS A SHARP SHEAR AXIS NORTH OF THE NORTHEAST
 CARIBBEAN ISLANDS IN 36-48 HOURS AND ENCOUNTER STRONG UPPER-LEVEL
 NORTHERLY OR NORTHEASTERLY FLOW. SHIPS MODEL OUTPUT ALSO FORECASTS
 HENRI TO ENCOUNTER A CONVERGENT UPPER-LEVEL FLOW AND A RATHER
 ANTICYCLONIC LOWER TROPOSPHERIC ENVIRONMENT...BOTH OF WHICH WOULD
 HAVE A NEGATIVE INFLUENCE ON THE CYCLONE. GIVEN THESE FACTORS...THE
 OFFICIAL FORECAST IS IN LINE WITH THE PREVIOUS ADVISORY AND A
 MAJORITY OF LARGE-SCALE DYNAMICAL MODELS...CALLING FOR THE
 DISSIPATION OF HENRI WITHIN 48 HOURS.
  
 LATEST CENTER FIXES SUGGEST A RATHER UNCERTAIN INITIAL MOTION.
 FORTUNATELY...A 0531 UTC AMSR-E PASS HAS ALLOWED FOR A MORE
 CONFIDENT INITIAL MOTION ESTIMATE OF 280/11...FARTHER LEFT THAN IN
 THE PREVIOUS ADVISORY. THE DOMINANT STEERING IS BEING PROVIDED BY
 MID-LEVEL SUBTROPICAL RIDGING NORTH OF HENRI...WITH A MINOR
 WEAKNESS AT UPPER LEVELS NORTHWEST OF THE CYCLONE. THIS FLOW
 PATTERN SHOULD FAVOR A GENERALLY WESTWARD TO WEST-NORTHWESTWARD
 TRACK UNTIL DISSIPATION. THE OFFICIAL FORECAST IS NUDGED SOUTH OF
 THE PREVIOUS ADVISORY TO ACCOUNT FOR ITS MORE SOUTHERN INITIAL
 POSITION AND MORE WESTERLY MOTION.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      07/0900Z 18.1N  56.1W    45 KT
  12HR VT     07/1800Z 18.9N  58.0W    45 KT
  24HR VT     08/0600Z 20.0N  60.3W    40 KT
  36HR VT     08/1800Z 21.2N  62.5W    30 KT
  48HR VT     09/0600Z 21.2N  63.2W    25 KT...REMNANT LOW
  72HR VT     10/0600Z...DISSIPATED
  
 $$
 FORECASTER KIMBERLAIN