ZCZC MIATCDAT2 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION HELENE DISCUSSION NUMBER 12 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072012 1000 AM CDT SAT AUG 18 2012 SATELLITE DATA...SURFACE OBSERVATIONS...AND MEXICAN RADAR DATA FROM ALTAMIRA INDICATE THAT THE CENTER OF HELENE IS LOCATED JUST INLAND FROM THE COAST VERY NEAR TAMPICO MEXICO. A NEW BURST OF DEEP CONVECTION APPEARS TO BE DEVELOPING NEAR THE CENTER...BUT THE DEEPEST CONVECTION LIES IN BANDS TO THE EAST OVER THE WATER. DVORAK FINAL-T ESTIMATES FROM TAFB AND SAB...AND SCATTEROMETER DATA...NO LONGER SUPPORT TROPICAL STORM STATUS...AND HELENE IS DOWNGRADED TO A TROPICAL DEPRESSION AT THIS TIME. WEAKENING SHOULD CONTINUE AS THE DEPRESSION MOVES OVER LAND...AND HELENE COULD BECOME A REMNANT LOW BY TONIGHT. ALTHOUGH THE GFS MODEL SHOWS HELENE RE-STRENGTHENING OVER WATER IN 2-3 DAYS...THE OFFICIAL FORECAST FOLLOWS THE OTHER MODELS AND INDICATES DISSIPATION BY 48 HOURS. AFTER MOVING VERY LITTLE LAST EVENING...HELENE APPEARS TO HAVE ACCELERATED OVERNIGHT AND HAS AN ESTIMATED MOTION OF 305/8 KT. THE CYCLONE SHOULD TURN NORTHWARD AND SLOW DOWN DURING THE NEXT DAY OR SO SINCE IT WILL BE STEERED AROUND THE WESTERN PERIPHERY OF A LOW/MID-LEVEL RIDGE...AND TRAPPED AGAINST THE EASTERN SLOPES OF THE SIERRA MADRE OCCIDENTALS. THE UPDATED NHC TRACK FORECAST IS JUST A LITTLE SLOWER THAN THE PREVIOUS ONE. FORECAST POSITIONS AND MAX WINDS INIT 18/1500Z 22.0N 98.0W 30 KT 35 MPH...INLAND 12H 19/0000Z 22.6N 98.7W 25 KT 30 MPH...INLAND 24H 19/1200Z 23.0N 98.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 20/0000Z 23.5N 98.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 20/1200Z...DISSIPATED $$ FORECASTER BERG 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 12:09:20 UTC