344 
 WTPZ41 KNHC 302036
 TCDEP1
 TROPICAL DEPRESSION ALVIN DISCUSSION NUMBER  16
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP012007
 200 PM PDT WED MAY 30 2007
  
 SATELLITE IMAGES INDICATE THAT THE CIRCULATION OF ALVIN HAS BECOME
 DISTORTED. THE MAIN CENTER...AS INDICATED BY MICROWAVE DATA...SEEMS
 TO BE ON THE EASTERN EDGE OF THE THUNDERSTORM ACTIVITY.
 HOWEVER...THERE IS SOME EVIDENCE OF A WEAK LOW-LEVEL SWIRL ON THE
 WESTERN SIDE OF WEAKENING DEEP CONVECTION. DESPITE THE GRADED
 SATELLITE PRESENTATION...A 1313 UTC QUIKSCAT PASS SUGGESTED WINDS
 OF ABOUT 30 KT. ALTHOUGH DVORAK INTENSITY ESTIMATES ARE FALLING...
 THE INITIAL INTENSITY WILL BE KEPT AT 30 KT...PERHAPS GENEROUSLY.
 THE INTENSITY FORECAST IS BASICALLY A BLEND OF PERSISTENCE AND THE
 SHIPS/GFDL MODELS. IT IS A BIT OF A MYSTERY WHY THIS SYSTEM HAS
 FAILED TO INTENSIFY...AND SINCE THE ENVIRONMENT IS ONLY GETTING
 LESS FAVORABLE WITH TIME...THERE IS NO GOOD REASON TO FORECAST
 ANYTHING BUT SLOW WEAKENING.
  
 THE BEST ESTIMATE OF INITIAL MOTION IS 290/3.  A STOUT RIDGE TO THE
 NORTH OF ALVIN SHOULD FORCE A WESTWARD TURN SOON... FOLLOWED BY A
 TURN MORE TOWARD THE WEST-SOUTHWEST IN A DAY OR TWO.  THERE IS
 RELATIVELY GOOD AGREEMENT ON THIS PATH...THOUGH THE UKMET KEEPS
 THE SYSTEM VIRTUALLY STATIONARY AS ALVIN GETS CAUGHT UP IN THE
 LARGER ITCZ CIRCULATION TO THE EAST.  THE OFFICIAL FORECAST IS
 BASICALLY AN UPDATE OF THE PREVIOUS FORECAST...NUDGED SOUTHWARD.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      30/2100Z 13.4N 115.0W    30 KT
  12HR VT     31/0600Z 13.5N 115.5W    25 KT
  24HR VT     31/1800Z 13.5N 116.4W    25 KT
  36HR VT     01/0600Z 13.4N 117.3W    25 KT
  48HR VT     01/1800Z 13.1N 118.2W    25 KT
  72HR VT     02/1800Z 12.5N 119.5W    20 KT...REMNANT LOW
  96HR VT     03/1800Z 11.7N 120.7W    20 KT...REMNANT LOW
 120HR VT     04/1800Z 10.5N 122.5W    20 KT...REMNANT LOW
  
 $$
 FORECASTER BLAKE