Tropical Storm NORMA

ZCZC MIATCDEP4 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM NORMA DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2 AM PDT SAT SEP 24 2005
 
ALTHOUGH SATELLITE FIXES PLACED THE CENTER OF NORMA WITHIN THE DEEP
CONVECTION...A MICROWAVE PASS AT 03Z AND A QUIKSCAT PASS AT 02Z
SHOW THAT IN FACT THE CENTER IS FARTHER EAST AND JUST OUTSIDE THE
CONVECTION.  THE QUIKSCAT PASS HAD A 40 KT VECTOR SOUTH OF THE
CENTER.  SINCE THAT TIME THE SHEAR HAS REASSERTED ITSELF AND IS
BLOWING THE DEEP CONVECTION WESTWARD AWAY FROM THE CIRCULATION
CENTER.  THE ADVISORY INTENSITY WILL REMAIN 45 KT FOR THIS ADVISORY
BUT MAY BE A LITTLE BIT HIGH.  THE SHIPS/GFS SHEAR DIAGNOSIS CALLS
FOR A GRADUAL INCREASE IN THE SHEAR OVER THE NEXT TWO TO THREE
DAYS...AND THIS INHIBIT ANY SIGNIFICANT INTENSIFICATION.  THE
OFFICIAL FORECAST IS CLOSER TO THE SHIPS GUIDANCE THAN TO THE
GFDL...WHICH BRINGS NORMA TO HURRICANE STRENGTH OVER THE NEXT DAY
OR SO.  BY LATE IN THE FORECAST PERIOD NORMA IS EXPECTED TO BE
MOVING OVER COOLER WATERS.

THE MICROWAVE DATA INDICATE THAT THE MOTION REMAINS 330/3.  STEERING
CURRENTS ARE PRESENTLY ILL-DEFINED...BUT GLOBAL MODELS ARE
FORECASTING HIGH PRESSURE TO BUILD OVER MEXICO OVER THE NEXT COUPLE
OF DAYS AS HURRICANE RITA MOVES NORTHWARD.  AS HIGH PRESSURE BUILDS
NORMA IS EXPECTED TO RESPOND BY MOVING A LITTLE FASTER TO THE
NORTHWEST.  LATE IN THE FORECAST PERIOD A LARGE UPPER TROUGH OVER
SOUTHERN CALIFORNIA IS FORECAST TO LIFT OUT AND LET HIGH PRESSURE
BUILD WESTWARD.  THIS...COUPLED WITH THE DECAY OF THE
SYSTEM...SHOULD RESULT IN A MORE WESTWARD MOTION.  MODEL GUIDANCE
IS WELL CLUSTERED FOR THE FIRST 48 HOURS.  AFTER THAT...THE
UKMET...WHICH HAS THE FASTEST INITIAL MOTION...GETS NORMA CAUGHT UP
IN THE UPPER TROUGH AND TAKES IT NORTHWARD.  THE REST OF THE
GUIDANCE FOLLOWS THE WESTERN SCENARIO DESCRIBED ABOVE.  THE
OFFICIAL FORECAST IS A LITTLE TO THE RIGHT OF THE PREVIOUS FORECAST
EARLY BUT FASTER TO THE WEST LATE.

FORECASTER FRANKLIN
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      24/0900Z 15.9N 110.3W    45 KT
 12HR VT     24/1800Z 16.3N 110.6W    45 KT
 24HR VT     25/0600Z 16.9N 111.0W    50 KT
 36HR VT     25/1800Z 17.5N 111.5W    50 KT
 48HR VT     26/0600Z 18.3N 112.3W    45 KT
 72HR VT     27/0600Z 20.0N 114.5W    45 KT
 96HR VT     28/0600Z 20.5N 116.5W    40 KT
120HR VT     29/0600Z 20.0N 118.5W    35 KT
 
 
$$
NNNN