000
WTNT42 KNHC 180908
TCDAT2
 
TROPICAL STORM HELENE DISCUSSION NUMBER  11
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL072012
400 AM CDT SAT AUG 18 2012
 
DEEP CONVECTION ASSOCIATED WITH HELENE HAS BEEN MINIMAL DURING THE
LAST SEVERAL HOURS. THE INITIAL WIND SPEED IS HELD AT 35 KT FOR
NOW...BUT IT IS POSSIBLE THAT HELENE IS A LITTLE WEAKER THAN THAT.
SINCE THE CYCLONE ONLY HAS A SHORT TIME BEFORE IT BEGINS
INTERACTING WITH LAND...STRENGTHENING IS NO LONGER ANTICIPATED.
THE NEW OFFICIAL FORECAST IS LOWERED FROM THE PREVIOUS ONE AND
SHOWS LITTLE CHANGE IN STRENGTH BEFORE LANDFALL. AFTER THE CENTER
MOVES INLAND...STEADY WEAKENING AND DEGENERATION TO A REMNANT LOW
ARE ANTICIPATED.
 
A SERIES OF MICROWAVE IMAGES AND RADAR IMAGERY FROM MEXICO INDICATE
THAT THE CENTER OF HELENE HAS BEEN WOBBLING AROUND. SMOOTHING
THROUGH THE WOBBLES YIELDS AN INITIAL MOTION ESTIMATE OF 315/6. A
MID-LEVEL RIDGE LOCATED OVER NORTHERN MEXICO APPEARS TO BE STRONG
ENOUGH TO STEER HELENE NORTHWESTWARD FOR ANOTHER 12 TO 24 HOURS.
THIS TRACK SHOULD TAKE HELENE INLAND OVER THE GULF COAST OF MEXICO
LATER TODAY. AFTER LANDFALL...THE WEAKENING SYSTEM IS EXPECTED TO
SLOW DOWN AND TURN TO THE NORTH ALONG THE COAST OF MEXICO UNTIL IT
DISSIPATES.
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  18/0900Z 21.6N  97.0W   35 KT  40 MPH
 12H  18/1800Z 21.9N  97.6W   35 KT  40 MPH...NEAR THE COAST
 24H  19/0600Z 22.4N  98.1W   35 KT  40 MPH...INLAND
 36H  19/1800Z 23.1N  97.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  20/0600Z 23.8N  97.8W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  21/0600Z...DISSIPATED
 
$$
FORECASTER CANGIALOSI/BEVEN