Tropical Storm OLIVIA
ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM TROPICAL STORM OLIVIA DISCUSSION NUMBER 6 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP162006 800 PM PDT TUE OCT 10 2006 OLIVIA'S DEEP CONVECTION CONTINUES TO BE LIMITED TO THE NORTHERN SEMICIRCLE OF THE CIRCULATION...AND HAS THE APPEARANCE OF AN AMORPHOUS BLOB. THERE HAS BEEN NO CHANGE TO THE DVORAK INTENSITY ESTIMATES FROM EARLIER TODAY...AND THUS NO CHANGE IS MADE TO THE WIND SPEED ESTIMATE FOR THIS ADVISORY. THE TROPICAL CYCLONE IS IN AN ENVIRONMENT OF FAIRLY STRONG SHEAR...ABOUT 25 KT FROM THE SOUTHWEST...AND THIS REGIME IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF DAYS OR MORE. AS OLIVIA MOVES OVER MARGINAL SSTS...IT SHOULD BEGIN TO WEAKEN. THE OFFICIAL FORECAST DOES NOT WEAKEN THE SYSTEM QUITE AS QUICKLY AS THE SHIPS OR FSU SUPERENSEMBLE GUIDANCE. GIVEN THE UNFAVORABLE ENVIRONMENT...OLIVIA COULD DISSIPATE SOONER THAN INDICATED BY THIS FORECAST. LATEST VISIBLE AND MICROWAVE FIXES SUGGEST THAT THE INITIAL MOTION IS NEAR 040/11. FOR THE NEXT DAY OR SO...OLIVIA IS LIKELY TO BE STEERED BY THE FLOW TO THE SOUTH OF A DEEP-LAYER LOW PRESSURE AREA TO ITS NORTH. THERE IS SOME POSSIBILITY THAT OLIVIA WILL INTERACT WITH THE REMNANT CIRCULATION OF NORMA...WHICH IS NOT FAR TO ITS EAST. SUCH AN INTERACTION COULD CAUSE A MORE SOUTHWARD MOTION THAN INDICATED BY THE LARGER-SCALE ENVIRONMENTAL STEERING. THE OFFICIAL FORECAST TRACK IS SLIGHTLY SOUTH OF THE PREVIOUS ONE. THIS IS WELL NORTH OF THE DYNAMICAL MODEL CONSENSUS BUT NOT FAR FROM THE NCEP GLOBAL ENSEMBLE MEAN. FORECAST POSITIONS AND MAX WINDS INITIAL 11/0300Z 16.5N 125.4W 40 KT 12HR VT 11/1200Z 17.2N 124.3W 40 KT 24HR VT 12/0000Z 17.8N 122.5W 35 KT 36HR VT 12/1200Z 18.5N 120.2W 30 KT 48HR VT 13/0000Z 19.0N 118.0W 25 KT 72HR VT 14/0000Z 19.5N 115.0W 20 KT...REMNANT LOW 96HR VT 15/0000Z...DISSIPATED $$ FORECASTER PASCH NNNN