000 WTNT43 KNHC 190846 TCDAT3 HURRICANE GORDON DISCUSSION NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL AL082012 500 AM AST SUN AUG 19 2012 GORDON REMAINS A WELL ORGANIZED HURRICANE BUT IT APPEARS TO HAVE WEAKENED A LITTLE. THE LATEST DVORAK CLASSIFICATIONS FROM TAFB...SAB...AND UW-CIMSS HAVE FALLEN SLIGHTLY FROM THE PREVIOUS VALUES LIKELY DUE TO A SLIGHT COOLING OF THE EYE AND A THINNING OF THE CONVECTIVE CLOUDS ON THE SOUTH SIDE OF THE CIRCULATION. THE INITIAL WIND SPEED IS ESTIMATED TO BE 90 KT...IN AGREEMENT WITH THE SATELLITE INTENSITY ESTIMATES. THE HURRICANE HAS NOW MOVED OVER SUB-26C WATERS AND CURRENTLY LIES IN AN ENVIRONMENT OF MODERATE WESTERLY SHEAR. SINCE THE SEA SURFACE TEMPERATURES DECREASE FURTHER ON THE EXPECTED TRACK AND BECAUSE GORDON IS ANTICIPATED TO MOVE INTO EVEN STRONGER SHEAR...STEADY WEAKENING IS FORECAST. POST-TROPICAL TRANSITION IS ANTICIPATED TO OCCUR IN 2 TO 3 DAYS...WHEN THE VERTICAL CIRCULATION IS EXPECTED TO BECOME SIGNIFICANTLY DECOUPLED. THE OFFICIAL FORECAST SHOWS THE POST-TROPICAL CYCLONE DISSIPATING BY DAY 4...FOLLOWING THE GLOBAL MODEL GUIDANCE. GORDON CONTINUES TO MOVE SWIFTLY EASTWARD AT ABOUT 20 KT. A SHORT WAVE TROUGH SEEN IN WATER VAPOR IMAGES NEAR 40N/40W IS SWINGING SOUTHEASTWARD TOWARD THE HURRICANE. THIS FEATURE SHOULD CAUSE THE CYCLONE TO TURN EAST-NORTHEASTWARD...TAKING GORDON VERY NEAR SANTA MARIA AND SAO MIGUEL ISLANDS IN THE EASTERN AZORES IN 18 TO 24 HOURS. AFTER PASSING THE AZORES...THE WEAKENING CYCLONE IS FORECAST TO SLOW DOWN SUBSTANTIALLY AND TURN BACK TO THE EAST BEFORE IT DISSIPATES. THE TRACK MODEL GUIDANCE REMAINS TIGHTLY CLUSTERED...AND THE OFFICIAL FORECAST LIES VERY NEAR THE MULTI-MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INIT 19/0900Z 34.9N 31.6W 90 KT 105 MPH 12H 19/1800Z 35.7N 28.6W 80 KT 90 MPH 24H 20/0600Z 37.2N 25.0W 70 KT 80 MPH 36H 20/1800Z 38.6N 22.0W 60 KT 70 MPH 48H 21/0600Z 39.4N 19.4W 50 KT 60 MPH 72H 22/0600Z 39.7N 16.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 23/0600Z...DISSIPATED $$ FORECASTER CANGIALOSI/BROWN