893 
 WTPZ42 KNHC 012100
 TCDEP2
 TROPICAL STORM BORIS DISCUSSION NUMBER  20
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP022008
 200 PM PDT TUE JUL 01 2008
  
 BORIS HAS FAILED TO DISPLAY AN EYE IN VISIBLE OR INFRARED GOES
 IMAGERY DURING THE PAST SEVERAL HOURS...BUT DVORAK INTENSITY
 ESTIMATES REMAIN 65 KT.  A QUIKSCAT OVERPASS AT 1425 UTC INCLUDED
 MAXIMUM WINDS OF ABOUT 55 KT IN THE 25-KM-RESOLUTION RETRIEVALS. 
 BORIS MIGHT STILL HAVE BEEN A HURRICANE AT THAT TIME...AS SUGGESTED
 BY A LONE 65-KT RETRIEVAL IN THE 12.5-KM QUIKSCAT RETRIEVALS...BUT
 THE GRADUAL DETERIORATION OF THE CONVECTIVE PATTERN SINCE THEN
 SUGGESTS THAT THE CYCLONE HAS PROBABLY WEAKENED.  THE ADVISORY
 INTENSITY IS REDUCED SLIGHTLY TO 60 KT.  SEA-SURFACE TEMPERATURES
 ALONG THE FORECAST TRACK WILL CONTINUE TO SLOWLY COOL
 DURING THE NEXT 24-36 HOURS OR SO...THEN DECREASE FASTER WHILE
 FALLING TO 25C OR LESS THEREAFTER.  THE OFFICIAL INTENSITY FORECAST
 CALLS FOR CONTINUED GRADUAL WEAKENING THROUGH 48 HOURS...FOLLOWED
 BY A MORE RAPID DECLINE AND EVENTUAL DEGENERATION TO A REMNANT LOW
 IN THE 3 TO 5 DAY TIME FRAME.  THE NEW INTENSITY FORECAST IS
 CHANGED LITTLE FROM THE PREVIOUS ADVISORY AND IS CLOSEST TO THE
 SHIPS AND LGEM GUIDANCE.
  
 BORIS CONTINUES TO SLOW DOWN...A LITTLE SOONER THAN PREVIOUSLY
 ANTICIPATED...AND THE INITIAL MOTION ESTIMATE IS NOW 280/7.  THE
 STORM IS HEADED INTO A WEAKNESS IN THE SUBTROPICAL RIDGE TO ITS
 NORTH THAT IS ASSOCIATED WITH AN EASTWARD-MOVING MID- TO
 UPPER-LEVEL TROUGH CURRENTLY ALONG 140W AND NORTH OF 25N.  A
 GENERAL WEST-NORTHWESTWARD MOTION OF BORIS WILL PROBABLY PREVAIL FOR
 THE NEXT COUPLE OF DAYS...UNTIL THAT TROUGH LIFTS OUT AND RIDGING
 BUILDS BACK IN.  BY THAT TIME...THE CYCLONE SHOULD BE WEAKENING OVER
 COOLER WATERS AND IS EXPECTED TO TURN TOWARD THE WEST OR EVEN SOUTH
 OF WEST IN THE LOWER-LEVEL FLOW.  THE NEW TRACK FORECAST IS
 ADJUSTED SLIGHTLY NORTH OF THE PREVIOUS ADVISORY...BUT IS OTHERWISE
 VERY SIMILAR...INCLUDING THAT THE TRACK REMAINS GENERALLY ON THE
 SOUTHERN SIDE OF THE GUIDANCE ENVELOPE...IN BEST AGREEMENT WITH THE
 GFS AND UKMET.
  
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      01/2100Z 15.0N 125.3W    60 KT
  12HR VT     02/0600Z 15.2N 126.4W    55 KT
  24HR VT     02/1800Z 15.6N 127.8W    50 KT
  36HR VT     03/0600Z 16.0N 129.2W    45 KT
  48HR VT     03/1800Z 16.2N 130.4W    40 KT
  72HR VT     04/1800Z 16.0N 133.0W    30 KT
  96HR VT     05/1800Z 15.5N 135.5W    25 KT...REMNANT LOW
 120HR VT     06/1800Z 15.0N 138.0W    25 KT...REMNANT LOW
  
 $$
 FORECASTER KNABB