000 WTPZ41 KNHC 010903 TCDEP1 TROPICAL STORM HENRIETTE DISCUSSION NUMBER 7 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP112007 200 AM PDT SAT SEP 01 2007 ENHANCED INFRARED SATELLITE IMAGERY INDICATES DEEP CONVECTION WITH TOPS AROUND -80C MAINLY TO THE WEST AND SOUTH OF THE CENTER. DEEP CONVECTION HAS ALSO EXPANDED NORTHWARD ALONG THE COAST OF MEXICO... BUT IT IS DIFFICULT TO SAY WHETHER IT IS DUE TO OROGRAPHIC EFFECTS. DVORAK INTENSITY ESTIMATES FROM BOTH TAFB AND SAB REMAIN AT 45 KT...AND A 0128 UTC QSCAT PASS ESTIMATED WINDS AROUND 45 KT. SO THE INITIAL INTENSITY WILL BE HELD AT 45 KT. THE INITIAL WIND RADII WERE EXPANDED BASED ON THE QSCAT PASS. THE EAST-NORTHEASTERLY SHEAR CURRENTLY AFFECTING THE CYCLONE IS FORECAST TO ABATE AND THE SEA SURFACE TEMPERATURES SHOULD REMAIN WARM FOR THE NEXT 3 DAYS. THEREFORE...GRADUAL STRENGTHENING IS FORECAST UNTIL HENRIETTE REACHES COOLER WATERS. THE INTERACTION THAT HENRIETTE HAS WITH LAND OVER THE NEXT 24 HOURS COULD HINDER INTENSIFICATION...HOWEVER IF THE CYCLONE REMAINS FURTHER OFFSHORE THAN FORECAST HENRIETTE COULD BECOME A STRONGER HURRICANE AS INDICATED BY THE SHIPS AND HWRF GUIDANCE. THE INITIAL MOTION IS 295/10...AND THE STORM IS BEING STEERED BY A RIDGE TO THE NORTH. THE MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT THAT A WEST-NORTHWEST MOTION WILL CONTINUE FOR THE NEXT 48 HOURS OR SO. THEREAFTER...THE MODELS DIVERGE AS TO WHEN THE RIDGE WILL WEAKEN ALLOWING FOR A MOTION MORE TOWARD THE NORTHWEST AND NORTH. THE GFDN...ECMWF...AND GFDL MODELS OPT FOR A MORE NORTHERLY TRACK OVER SOUTHERN BAJA. ON THE OTHER HAND...THE HWRF...GFS...AND NOGAPS MAINTAIN A WEST TO WEST-NORTHWEST MOTION LONGER AND KEEP THE CYCLONE WEST OF THE BAJA PENINSULA THROUGH 5 DAYS. THE OFFICIAL TRACK FORECAST LEANS MORE TOWARD THE LATTER AND IS CLOSE TO THE PREVIOUS ADVISORY. FORECAST POSITIONS AND MAX WINDS INITIAL 01/0900Z 17.4N 103.2W 45 KT 12HR VT 01/1800Z 18.1N 104.6W 50 KT 24HR VT 02/0600Z 18.8N 106.2W 55 KT 36HR VT 02/1800Z 19.4N 107.8W 65 KT 48HR VT 03/0600Z 19.9N 109.3W 70 KT 72HR VT 04/0600Z 21.0N 111.5W 70 KT 96HR VT 05/0600Z 22.5N 113.5W 60 KT 120HR VT 06/0600Z 25.0N 115.0W 50 KT $$ FORECASTER MAINELLI