000 WTNT42 KNHC 220853 TCDAT2 TROPICAL DEPRESSION BRET DISCUSSION NUMBER 19 NWS NATIONAL HURRICANE CENTER MIAMI FL AL022011 500 AM AST FRI JUL 22 2011 BRET REMAINS A MAVERICK TROPICAL CYCLONE BY REFUSING TO DISSIPATE DESPITE EXPERIENCING VERY HOSTILE VERTICAL WIND SHEAR CONDITIONS OVER THE PAST 12 HOURS. PREVIOUSLY DEVOID OF ANY CONVECTION...SOME MODEST CONVECTION WITH CLOUD TOPS TO -45C HAS RECENTLY DEVELOPED IN THE SOUTHEAST QUADRANT. IN ADDITION...SHIP WDC6925 LOCATED ABOUT 80 NMI SOUTH OF THE CENTER REPORTED A SOUTHWEST WIND OF 24 KT AT 06Z. THIS INFORMATION...COMBINED WITH A SATELLITE INTENSITY ESTIMATE OF T2.0/30 KT FROM TAFB...IS JUSTIFICATION FOR MAINTAINING BRET AS A 30-KT DEPRESSION FOR THIS ADVISORY. BRET HAS CONTINUED TO ACCELERATE AND THE INITIAL MOTION IS NOW 055/18. THE CYCLONE IS FORECAST TO MOVE TOWARD THE NORTHEAST TODAY AND TURN TOWARD THE EAST-NORTHEAST BY 24 HOURS AS THE CYCLONE MOVES ALONG THE NORTHERN PERIPHERY OF A DEEP LAYER SUBTROPICAL RIDGE SITUATED ALONG 30N LATITUDE. THIS WILL RESULT IN BRET MOVING OVER MUCH COLDER WATERS...WHICH WILL HASTEN ITS DEMISE. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY AND IS CLOSE TO THE TRACK MODEL CONSENSUS. DURING THE NEXT 12-18 HOURS...A NARROW UPPER-LEVEL RIDGE LOCATED JUST TO THE NORTHWEST OF BRET IS FORECAST BY ALL OF THE GLOBAL MODELS TO SLIDE SOUTHEASTWARD AND PASS OVER THE CYCLONE. THIS WILL BRIEFLY REDUCE THE WIND SHEAR...WHICH MAY ALLOW FOR ONE FINAL SHORT BURST OF CONVECTION TO OCCUR NEAR THE CENTER. FOR THAT REASON... BRET IS BEING MAINTAINED AS A TROPICAL CYCLONE FOR THE NEXT 12-24 HOURS IN THE OFFICIAL FORECAST. AFTERWARD...HOWEVER...MUCH COOLER SSTS OF NEAR 22C BENEATH THE CYCLONE SHOULD RESULT IN DISSIPATION BY 36-48 HOURS. THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY AND IS A LITTLE ABOVE THE SHIPS AND LGEM INTENSITY FORECASTS. FORECAST POSITIONS AND MAX WINDS INIT 22/0900Z 36.7N 66.5W 30 KT 35 MPH 12H 22/1800Z 38.0N 63.6W 30 KT 35 MPH 24H 23/0600Z 39.4N 59.5W 25 KT 30 MPH 36H 23/1800Z 40.9N 54.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 24/0600Z...DISSIPATED $$ FORECASTER STEWART