WTPZ43 KNHC 180838 TCDEP3 TROPICAL DEPRESSION MANUEL DISCUSSION NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL EP132013 200 AM PDT WED SEP 18 2013 MANUEL CONTINUES TO PRODUCE A SOMEWHAT RAGGED AREA OF DEEP CONVECTION TO THE EAST OF THE ESTIMATED CENTER POSITION. THE CONVECTION DOES NOT SHOW A LOT OF CURVATURE...AND DVORAK CLASSIFICATIONS FROM TAFB AND SAB SUPPORT KEEPING THE INITIAL INTENSITY AT 30 KT FOR THIS ADVISORY. AN ENVIRONMENT OF LOW SHEAR AND WARM SSTS SHOULD SUPPORT GRADUAL STRENGTHENING DURING THE NEXT COUPLE OF DAYS. BY 72 HOURS THE CYCLONE WILL BE VERY CLOSE TO THE BAJA CALIFORNIA PENINSULA...AND INTERACTION WITH LAND SHOULD RESULT IN WEAKENING AROUND THAT TIME. MANUEL IS EXPECTED TO BECOME A REMNANT LOW BY DAY 4 OVER THE MUCH COOLER PACIFIC WATERS WEST OF THE PENINSULA...AND THE CYCLONE SHOULD DISSIPATE BY THE END OF THE FORECAST PERIOD. THE NHC INTENSITY FORECAST IS CLOSE TO THE SHIPS GUIDANCE THROUGHOUT. THE INITIAL MOTION ESTIMATE IS A SOMEWHAT UNCERTAIN 320/04. MICROWAVE IMAGERY FROM EARLIER TONIGHT SUGGESTED THAT THE CENTER WAS LOCATED A LITTLE TO THE EAST AND MOVING A LITTLE SLOWER THAN PREVIOUSLY THOUGHT. MANUEL SHOULD CONTINUE MOVING SLOWLY NORTHWESTWARD TODAY AND TONIGHT...AS THE CYCLONE IS STEERED BY A RIDGE CENTERED WELL TO THE EAST. A TROUGH MOVING INTO THE WESTERN UNITED STATES WILL CAUSE THE STEERING FLOW TO WEAKEN BY 36 TO 48 HOURS. AS A RESULT...MANUEL WILL SLOW AND GRADUALLY TURN WESTWARD BY 72 HOURS AND THEN SOUTHWESTWARD BY 96 HOURS AS A WEAK RIDGE REBUILDS TO THE NORTHWEST. THE NEW NHC TRACK IS SLOWER AND TO THE RIGHT DURING THE FIRST COUPLE OF DAYS...FOLLOWING THE TREND OF THE GFS...GEFS ENSEMBLE MEAN...AND ECMWF. THIS ADJUSTMENT RESULTS IN MANUEL REMAINING OFFSHORE OF THE EAST COAST OF THE BAJA CALIFORNIA PENINSULA UNTIL AROUND 72 HOURS. LATER IN THE PERIOD THE AFOREMENTIONED MODELS ALL SHOW A SHARP SOUTHWESTWARD TURN. THE NHC FORECAST FOLLOWS THIS GENERAL TREND BUT WITH A MORE GRADUAL BEND IN THE MOTION...AND LIES TO THE RIGHT...OR NORTH...OF THOSE AIDS AT DAYS 3 AND 4. FORECAST POSITIONS AND MAX WINDS INIT 18/0900Z 23.2N 107.8W 30 KT 35 MPH 12H 18/1800Z 23.6N 108.3W 35 KT 40 MPH 24H 19/0600Z 24.1N 108.9W 40 KT 45 MPH 36H 19/1800Z 24.3N 109.3W 45 KT 50 MPH 48H 20/0600Z 24.5N 109.7W 45 KT 50 MPH 72H 21/0600Z 24.2N 110.4W 40 KT 45 MPH 96H 22/0600Z 23.5N 111.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 23/0600Z...DISSIPATED $$ FORECASTER BRENNAN WWWW For more information, go to middletnweather.info
Posted on: Wed, 18 Sep 2013 08:39:03 +0000