000
WTPZ45 KNHC 100830
TCDEP5
HURRICANE LINDA DISCUSSION NUMBER  13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP152009
200 AM PDT THU SEP 10 2009

THE EYE DISAPPEARED FROM GEOSTATIONARY IMAGES AROUND 0300 UTC. 
SUBSEQUENT MICROWAVE IMAGERY DEPICTED A PARTIAL EYEWALL THAT WAS
OPEN OVER THE SOUTHERN SEMICIRCLE.  DVORAK INTENSITY ESTIMATES ARE
77 KT AND 65 KT FROM TAFB AND SAB...RESPECTIVELY...SO THE ADVISORY
INTENSITY IS HELD AT 70 KT.  THE OVERALL CLOUD PATTERN HAS BECOME
SLIGHTLY LESS ORGANIZED IN APPEARANCE AND ELONGATED FROM SOUTH TO
NORTH...INDICATIVE OF SOUTHERLY OR SOUTH-SOUTHWESTERLY SHEAR.   
WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL CYCLONIC SHEAR AXIS OR
TROUGH JUST TO THE WEST OF LINDA AND AN UPPER-LEVEL RIDGE TO THE
EAST...AND THESE FEATURES ARE LIKELY PRODUCING THE SHEAR.  GLOBAL
MODELS PREDICT THE TROUGH TO SHIFT TO THE NORTHWEST IN A COUPLE OF
DAYS WITH STRONG WEST-SOUTHWESTERLY FLOW OVER THE TROPICAL CYCLONE. 
THE SHIPS MODEL INDICATES SOUTH-SOUTHWESTERLY TO WESTERLY SHEAR IN
THE 20 TO 25 KT RANGE OVER THE NEXT SEVERAL DAYS.  THIS UNFAVORABLE
DYNAMIC ENVIRONMENT...ALONG WITH SEA SURFACE TEMPERATURES COOLING
BELOW 24 DEG C IN ABOUT 48 HOURS...SHOULD RESULT IN WEAKENING.  THE
OFFICIAL WIND SPEED FORECAST GOES WITH THE CONSENSUS OF THE
OBJECTIVE INTENSITY GUIDANCE.

THE MICROWAVE IMAGE DATA INDICATES THAT THE CENTER IS A LITTLE SOUTH
AND WEST OF WHERE IT APPEARS TO BE ON GEOSTATIONARY IMAGES. 
INITIAL MOTION IS ESTIMATED TO BE BETWEEN NORTHWEST AND
NORTH-NORTHWEST...325/7.  LINDA IS EXPECTED TO MOVE THROUGH A
WEAKNESS IN THE MID-LEVEL SUBTROPICAL RIDGE FOR THE NEXT DAY OR
TWO.  IN THE LATTER HALF OF THE FORECAST PERIOD...DYNAMICAL MODELS
DEPICT A MID-TROPOSPHERIC TROUGH AMPLIFYING TO THE NORTH OF LINDA. 
ALTHOUGH THIS COULD CAUSE THE CYCLONE TO TURN NORTHEASTWARD BY DAYS
4-5...LINDA OR ITS REMNANTS WILL PROBABLY BE STEERED BY THE
LOWER-TROPOSPHERIC FLOW BY THAT TIME.  THESE LOW LEVEL WINDS ARE
PREDICTED TO BE VERY WEAK...SO THE OFFICIAL TRACK FORECAST SHOWS A
VERY SLOW MOTION FROM 72-120 HOURS.  THIS IS ONLY SLIGHTLY WEST OF
AND A TAD SLOWER THAN THE PREVIOUS OFFICIAL FORECAST TRACK.

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      10/0900Z 17.8N 129.6W    70 KT
 12HR VT     10/1800Z 18.8N 130.3W    70 KT
 24HR VT     11/0600Z 20.1N 131.1W    65 KT
 36HR VT     11/1800Z 21.0N 131.9W    55 KT
 48HR VT     12/0600Z 21.6N 132.6W    40 KT
 72HR VT     13/0600Z 22.4N 133.5W    25 KT
 96HR VT     14/0600Z 23.0N 134.0W    20 KT...REMNANT LOW
120HR VT     15/0600Z 23.5N 134.0W    20 KT...REMNANT LOW
 
$$
FORECASTER PASCH