000 WTPZ41 KNHC 010301 TCDEP1 TROPICAL STORM HENRIETTE DISCUSSION NUMBER 6 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP112007 800 PM PDT FRI AUG 31 2007 THIS EVENING'S SATELLITE PRESENTATION DEPICTS A SLIGHT CHANGE IN HENRIETTE'S CLOUD PATTERN. ALTHOUGH THE CIRCULATION CENTER REMAINS JUST BENEATH THE NORTHEASTERN PORTION OF THE DEEPEST CONVECTION...THE COLDEST CLOUD TOP CANOPY HAS INCREASED SOMEWHAT IN AREAL EXTENT. DVORAK INTENSITY ESTIMATES ARE 45 KT FROM BOTH TAFB AND SAB...AND THE INITIAL INTENSITY IS INCREASED TO 45 KT. VERY LITTLE ADJUSTMENT HAS BEEN MADE TO THE PREVIOUS INTENSITY FORECAST. THE OFFICIAL FORECAST CONFORMS WITH A BLEND OF THE SUPER ENSEMBLE AND THE LOGISTICAL GROWTH EQUATION MODEL...WHICH BOTH INDICATE HURRICANE STRENGTH IN 48 HOURS. BEYOND DAY 2...A SLIGHT WEAKENING IS INDICATED AS 10-20 KT UPPER LEVEL WESTERLIES ASSOCIATED WITH A RETROGRADING UPPER TROUGH OVER BAJA CALIFORNIA ARE EXPECTED TO GRADUALLY SPREAD SOUTHWARD. BASED ON AN EARLIER 1752Z TRMM OVERPASS...HENRIETTE'S CENTER LOCATION HAS BEEN ADJUSTED NORTH-NORTHEASTWARD...AND THE INITIAL MOTION IS CURRENTLY 300/10. A MID- TROPOSPHERIC RIDGE EXTENDING SOUTHWESTWARD FROM THE NORTHWEST PORTION OF MEXICO SHOULD INFLUENCE A GENERAL WEST-NORTHWESTWARD MOTION DURING THE NEXT 72 HOURS. AFTERWARD...THE PICTURE BECOMES A BIT UNCLEAR. THE GFS...SUPER ENSEMBLE...AND THE NOGAPS ALL FORECAST A TURN TOWARD THE NORTHWEST IN RESPONSE TO AN INCREASING WEAKNESS IN THE RIDGE JUST WEST OF THE PENINSULA. ON THE OTHER HAND...THE UKMET...HWRF AND THE GFDL SUGGEST THAT THE RIDGING WILL BUILD WESTWARD OVER SOUTHERN BAJA CALIFORNIA...INSTEAD OF THE AFOREMENTIONED AMPLIFYING WEAKNESS. THE OFFICIAL FORECAST IS A COMPROMISE OF BOTH MODEL CLUSTER SOLUTIONS...WHICH INDICATES A CONTINUED WEST-NORTHWESTWARD MOTION BUT SIGNIFICANTLY SLOWER THAN THE FIRST 48 HOURS OF THE TRACK FORECAST. FORECAST POSITIONS AND MAX WINDS INITIAL 01/0300Z 17.1N 102.1W 45 KT 12HR VT 01/1200Z 17.8N 103.5W 50 KT 24HR VT 02/0000Z 18.7N 105.1W 55 KT 36HR VT 02/1200Z 19.5N 106.6W 60 KT 48HR VT 03/0000Z 20.2N 108.2W 65 KT 72HR VT 04/0000Z 21.5N 111.0W 65 KT 96HR VT 05/0000Z 22.5N 113.0W 60 KT 120HR VT 06/0000Z 24.0N 115.0W 50 KT $$ FORECASTER ROBERTS/BEVEN