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
Alternate Formats
About Alternates -
E-Mail Advisories -
RSS Feeds
Cyclone Forecasts
Latest Advisory -
Past Advisories -
About Advisories
Marine Forecasts
Latest Products -
About Marine Products
Tools & Data
Satellite Imagery -
US Weather Radar -
Aircraft Recon -
Local Data Archive -
Forecast Verification -
Deadliest/Costliest/Most Intense
Learn About Hurricanes
Storm Names
Wind Scale -
Prepare -
Climatology -
NHC Glossary -
NHC Acronyms -
Frequently Asked Questions -
AOML Hurricane-Research Division
About Us
About NHC -
Mission/Vision -
Other NCEP Centers -
NHC Staff -
Visitor Information -
NHC Library
NOAA/
National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida, 33165-2149 USA
nhcwebmaster@noaa.gov
Disclaimer
Privacy Policy
Credits
About Us
Glossary
Career Opportunities
Page last modified: Saturday, 24-Sep-2005 08:40:22 UTC