000
WTPZ42 KNHC 020246
TCDEP2
TROPICAL STORM BORIS DISCUSSION NUMBER  21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP022008
800 PM PDT TUE JUL 01 2008
 
THE OVERALL CLOUD PATTERN OF BORIS HAS CHANGED VERY LITTLE THIS
EVENING.  HOWEVER...AN AMSR-E MICROWAVE OVERPASS SUGGESTS THAT THE
EYE FEATURE SEEN EARLIER TODAY IN MICROWAVE IMAGERY HAS CONTINUED
TO ERODE.  THE CURRENT INTENSITY WILL REMAIN 60 KT...WHICH IS
SUPPORTED BY THE AVERAGE OF DVORAK T AND CI NUMBERS FROM BOTH 
SAB AND TAFB. 

BORIS HAS JOGGED NORTHWESTWARD DURING THE PAST SEVERAL HOURS...
BUT A LONGER TERM AVERAGE YIELDS AN INITIAL MOTION ESTIMATE OF
WEST-NORTHWEST OR 295/7 KT.  BORIS IS EXPECTED TO MOVE ON A GENERAL
WEST-NORTHWESTWARD TRACK DURING THE NEXT 24-36 HOURS TOWARD A
WEAKNESS IN THE SUBTROPICAL RIDGE.  THE RIDGE IS EXPECTED TO
REBUILD WESTWARD AFTER 36 HOURS WHICH SHOULD ALLOW BORIS TO TURN
BACK TOWARD THE WEST.  LATER...NORTHEASTERLY LOW-LEVEL FLOW SHOULD
STEER BORIS SOUTHWESTWARD AS THE CYCLONE WEAKENS AND BECOMES A
SHALLOWER SYSTEM.  THE NEW NHC FORECAST TRACK IS A LITTLE SLOWER
AND NORTH OF THE PREVIOUS TRACK...AND IS CLOSE TO THE GFS...
UKMET...AND FSSE SUPERENSEMBLE.  THE 18Z NOGAPS SOLUTION...WHICH
SHOWS LITTLE MOTION DURING THE NEXT FEW DAYS...IS DISCOUNTED.

SEA-SURFACE TEMPERATURES ALONG THE FORECAST TRACK ARE EXPECTED TO
CONTINUE TO COOL. THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO THE
PREVIOUS FORECAST...AND CALLS FOR GRADUAL WEAKENING DURING THE NEXT
2 DAYS...FOLLOWED BY FASTER WEAKENING TO A REMNANT LOW IN 3-4 DAYS.
THE NEW INTENSITY FORECAST FOLLOWS THE ICON INTENSITY CONSENSUS
CLOSELY.  IT SHOULD BE NOTED THAT IF BORIS MOVES TO THE RIGHT OF
THE FORECAST TRACK...THE SSTS WOULD DECREASE QUICKER WHICH WOULD
RESULT IN A WEAKER CYCLONE THAN INDICATED BELOW. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/0300Z 15.5N 125.9W    60 KT
 12HR VT     02/1200Z 15.9N 126.8W    55 KT
 24HR VT     03/0000Z 16.4N 128.1W    50 KT
 36HR VT     03/1200Z 16.8N 129.2W    45 KT
 48HR VT     04/0000Z 16.9N 130.3W    40 KT
 72HR VT     05/0000Z 16.6N 132.5W    30 KT
 96HR VT     06/0000Z 16.0N 135.0W    25 KT...REMNANT LOW
120HR VT     07/0000Z 15.5N 137.5W    25 KT...REMNANT LOW
 
$$
FORECASTER BROWN