WTPA42 PHFO 231506
TCDCP2

TROPICAL STORM NEKI DISCUSSION NUMBER  20
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP032009
500 AM HST FRI OCT 23 2009

NEKI HAS WEAKENED SIGNIFICANTLY OVER THE PAST 12 HOURS. OVER THE 
PAST 6 HOURS IN PARTICULAR...NEKI HAS STRUGGLED TO MAINTAIN DEEP 
CONVECTION AND AT 430 AM HST ITS ARGUABLE IF THERE IS ANY AT ALL. 
AGENCY DVORAK ESTIMATES CAME IN AT 3.5 3.5 AND 2.5 FROM PHFO SAB AND 
PGTW RESPECTIVELY...THE LATTER BREAKING CONSTRAINTS. COMBINED WITH 
THE POOR SATELLITE PRESENTATION...SEE NO REASON TO MAINTAIN 
HURRICANE STRENGTH AND HAVE DOWNGRADED NEKI TO A TROPICAL STORM. THE 
RAPID WEAKENING ALSO PRESENTS A CHALLENGE ON THE CENTER POSITION. 
BELIEVE WHAT LITTLE CONVECTION EXISTS IS BEING SHEARED CONSIDERABLY 
TO THE NORTH AND EAST...SO RELIED ON LIMITED MICROWAVE IMAGERY AND 
SIMPLE EXTRAPOLATION FOR THE 1200 UTC POSITION. 
 
MODELS ARE IN GOOD AGREEMENT AND BETTER REFLECT THE SLOW DOWN OF 
NEKI OVER THE PAST 24 HOURS. AS A RESULT...THE ENTIRE FORECAST TRACK 
WAS PULLED BACK EVEN FURTHER FROM THE PREVIOUS PACKAGE. THROUGH 48 
HOURS...EXPECT LESS THAN 10 KT OF FORWARD MOTION WITH NO SIGNIFICANT 
ENVIRONMENTAL PUSH. AFTER 48 HOURS...A WEAKENED NEKI WILL PICK UP 
SOME SPEED AS IT STARTS TO BE ABSORBED INTO A MUCH LARGER LOW 
PRESSURE SYSTEM TRACKING ACROSS THE NORTH PACIFIC. THE LATEST 
FORECAST IS SLIGHTLY RIGHT OF CENTER DOWN THE GUIDANCE 
ENVELOPE...AND CLOSE TO THE GFDL AND HWRF.
 
SHIPS CONTINUES TO INDICATE INCREASING SHEAR AND COOLER SEA SURFACE 
TEMPERATURES IN THE COMING DAYS. THE CURRENT SHEAR IS REALLY BEATING 
NEKI DOWN. HAVE LOWERED THE FORECAST INTENSITY ACROSS THE 
BOARD...MAKING NEKI A REMNANT LOW AT 72 HOURS.
 
ON ITS CURRENT TRACK...NEKI WILL CONTINUE TO IMPACT PORTIONS OF THE 
PAPAHANAUMOKUAKEA NATIONAL MONUMENT BETWEEN MARO REEF AND NIHOA 
TODAY. THE HURRICANE WARNING FOR THE MONUMENT FROM NIHOA ISLAND TO 
MARO REEF IS CANCELLED AND REPLACED BY A TROPICAL STORM WARNING FOR 
THE SAME AREA.  LARGE SWELLS FROM THE SOUTH WILL CONTINUE TO IMPACT 
PORTIONS OF THE WARNING AREA TODAY AND TONIGHT. SEAS UP TO 20 FT AND 
SURF UP TO 25 FEET WILL CONTINUE TO BATTER ISLANDS IN THE WARNING 
AREA...ESPECIALLY AROUND FRENCH FRIGATE SHOALS. SEAS AND SURF WILL 
BEGIN TO SUBSIDE TONIGHT AS NEKI WEAKENS FURTHER.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      23/1500Z 22.8N 165.6W    60 KT
 12HR VT     24/0000Z 23.7N 165.4W    55 KT
 24HR VT     24/1200Z 24.9N 164.9W    45 KT
 36HR VT     25/0000Z 26.2N 164.0W    40 KT
 48HR VT     25/1200Z 27.4N 162.9W    30 KT
 72HR VT     26/1200Z 30.5N 160.3W    25 KT...REMNANT LOW
 96HR VT     27/1200Z 36.6N 156.9W    20 KT...DISSIPATING
 
$$
FORECASTER TANABE