ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM TROPICAL STORM FERNANDA DISCUSSION NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL EP062011 800 AM PDT WED AUG 17 2011 FERNANDA HAS A SOMEWHAT HOLLOW APPEARANCE. THE EXTENT AND DEPTH OF ITS CONVECTION HAS BEEN DECREASING...POSSIBLY IN RESPONSE TO THE INGESTION OF A DRIER AND MORE STABLE AIR MASS FROM THE NORTH. WHATEVER REMAINING CONVECTION IS IN A BAND WRAPPING AROUND THE SOUTHERN SEMICIRCLE. HOWEVER...SEVERAL MICROWAVE PASSES HAVE INDICATED NO SIGNIFICANT CHANGE IN THE CENTRAL FEATURES OF THE STORM...WITH A WELL DEFINED CIRCULATION AND OUTFLOW THAT REMAINS WELL ESTABLISHED. CURRENT CI NUMBERS REMAIN AT 3.0...SO THE INITIAL INTENSITY IS HELD AT 45 KT. THE INITIAL MOTION ESTIMATE IS 275/08...WITH RECENT FIXES POSSIBLY SUGGESTING A MOTION SLIGHTLY TO THE RIGHT. FERNANDA IS APPROACHING THE WESTERN END OF A SUBTROPICAL RIDGE. A LONGWAVE TROUGH ALONG 140W IS FORECAST TO LIFT OUT DURING THE NEXT COUPLE OF DAYS...LEAVING A WEAKNESS IN ITS WAKE. GLOBAL MODELS SHOW THE TRACK OF FERNANDA TURNING WEST-NORTHWESTWARD IN RESPONSE TO THE WEAKNESS BUT THEN BENDING TOWARD THE WEST AS THE CYCLONE WEAKENS AND FERNANDA GETS CAUGHT UNDER A LOW-/MID-LEVEL RIDGE. THERE IS A FAIR AMOUNT OF SPREAD IN THE GUIDANCE...WITH THE GFS/HWRF/GFDL FAVORING A MORE SIGNIFICANT WEAKNESS AND MORE NORTHWARD FORECAST TRACKS. THE UKMET/ECMWF SHOW STRONGER RIDGING AND ARE ON THE SOUTHERN EDGE OF THE GUIDANCE ENVELOPE. THE OFFICIAL NHC TRACK HAS CHANGED LITTLE SINCE THE LAST ADVISORY AND IS GENERALLY IN THE MIDDLE OF THESE TWO CAMPS...TO THE LEFT OF THE MULTI-MODEL CONSENSUS TVCE. THE SHIPS MODEL SHOWS FERNANDA EMBEDDED IN A LOW SHEAR ENVIRONMENT DURING THE NEXT 48 HOURS. HOWEVER...SEA SURFACE TEMPERATURES DECREASE ALONG THE PATH OF THE STORM...ALBEIT SLOWLY...AND FERNANDA IS LIKELY TO CONTINUE INGESTING A DRIER AND MORE STABLE AIR MASS FROM THE NORTH AND WEST. THESE FACTORS SUGGEST THAT THE CYCLONE SHOULD ESSENTIALLY MAINTAIN ITS STRENGTH DURING THE NEXT DAY OR TWO. AFTER THAT...INCREASING SHEAR RELATED TO A UPPER-LEVEL CYCLONIC SHEAR AXIS SOUTH OF HAWAII AND EVEN COOLER WATERS SHOULD RESULT IN A WEAKENING TREND. THE OFFICIAL NHC FORECAST IS SIMILAR TO THE PREVIOUS ONE AND IS FAIRLY CLOSE TO THE STATISTICAL-DYNAMICAL MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INIT 17/1500Z 11.8N 137.8W 45 KT 50 MPH 12H 18/0000Z 12.2N 138.9W 50 KT 60 MPH 24H 18/1200Z 13.0N 140.3W 50 KT 60 MPH 36H 19/0000Z 14.0N 142.0W 45 KT 50 MPH 48H 19/1200Z 14.9N 143.7W 45 KT 50 MPH 72H 20/1200Z 15.2N 146.2W 35 KT 40 MPH 96H 21/1200Z 16.5N 151.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 22/1200Z 16.5N 155.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ FORECASTER KIMBERLAIN 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: Tuesday, 17-Jul-2012 13:44:15 UTC