ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM TROPICAL STORM ALETTA DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL EP012012 800 PM PDT TUE MAY 15 2012 AFTER BECOMING A LITTLE BETTER ORGANIZED EARLIER TODAY...ALETTA HAS RECENTLY BECOME RATHER RAGGED-LOOKING. BANDING FEATURES HAVE BECOME ILL-DEFINED...AND ARC CLOUDS HAVE BEEN EMANATING FROM THE CYCLONE OVER THE WESTERN SEMICIRCLE...WHICH IS USUALLY INDICATIVE OF DRIER MID-LEVEL AIR ENTERING THE CIRCULATION. THE CURRENT INTENSITY IS HELD AT 40 KT...AND THIS MAY BE GENEROUS GIVEN THE CURRENT APPEARANCE OF THE SYSTEM. THE LACK OF CONVECTIVE CLOUDS TO THE WEST AND NORTHWEST OF ALETTA IMPLIES A MORE STABLE AND DRIER ENVIRONMENT. THIS...ALONG WITH INCREASING VERTICAL SHEAR...SHOULD CAUSE A WEAKENING TREND TO COMMENCE WITHIN THE NEXT DAY OR SO. THE OFFICIAL INTENSITY FORECAST IS IDENTICAL TO THE PREVIOUS ONE AND CLOSE TO THE LGEM GUIDANCE. THE CENTER HAS BECOME DIFFICULT TO LOCATE IN GEOSTATIONARY AND MICROWAVE IMAGERY...SO THE INITIAL MOTION IS A RATHER UNCERTAIN 285/9. ALL OF THE RECENT DYNAMICAL TRACK GUIDANCE NOW SHOW A TURN TOWARD THE NORTH AND NORTHEAST OVER THE NEXT FEW DAYS AS THE TROPICAL CYCLONE BECOMES EMBEDDED IN A BROAD LOW- TO MID-LEVEL SOUTHWESTERLY FLOW THAT DEVELOPS TO THE SOUTHWEST OF MAINLAND MEXICO. THE OFFICIAL TRACK FORECAST HAS BEEN SHIFTED TO THE RIGHT OF THE PREVIOUS ONE...BUT NOT NEARLY AS FAR TO THE EAST AS SOME OF THE MODELS AND THE MODEL CONSENSUS. THE NEW NHC FORECAST IS FAIRLY CLOSE TO THE LATEST GFS ENSEMBLE MEAN. FORECAST POSITIONS AND MAX WINDS INIT 16/0300Z 11.7N 110.9W 40 KT 45 MPH 12H 16/1200Z 12.0N 112.2W 40 KT 45 MPH 24H 17/0000Z 12.4N 114.0W 40 KT 45 MPH 36H 17/1200Z 12.7N 115.0W 35 KT 40 MPH 48H 18/0000Z 13.0N 115.5W 30 KT 35 MPH 72H 19/0000Z 13.5N 116.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 20/0000Z 14.5N 115.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 21/0000Z...DISSIPATED $$ FORECASTER PASCH 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: Monday, 31-Dec-2012 12:10:03 UTC