825 
 WTPA42 PHFO 191505
 TCDCP2
 
 TROPICAL STORM NEKI DISCUSSION NUMBER   4
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP032009
 500 AM HST MON OCT 19 2009
 
 THE LARGE TROPICAL CYCLONE LOCATED FAR SOUTH OF THE MAIN HAWAIIAN
 ISLANDS...CURRENTLY MORE THAN 800 MILES SOUTH OF HONOLULU 
 HAWAII...REMAINS VERY IMPRESSIVE IN SATELLITE IMAGERY EARLY THIS
 MORNING. LARGE SPIRALING CONVECTIVE BANDS ARE FEEDING INTO DEEP
 TROPICAL CONVECTION THAT IS CLOSE TO THE APPARENT LOW-LEVEL
 CIRCULATION CENTER...OR LLCC. AS MENTIONED IN THE PREVIOUS
 DISCUSSION...A TROPICAL CYCLONE OF THIS TYPE IS LIKELY A RARE
 OCCURRENCE OVER THE NORTH CENTRAL PACIFIC OCEAN. THESE TYPES OF
 SYSTEMS ARE MUCH MORE COMMON OVER THE NORTHWESTERN PACIFIC OCEAN.
 THEREFORE...DESPITE THE SLOW...BUT STEADY DEVELOPMENT OF THIS TYPE
 OF TROPICAL SYSTEM...DO NOT UNDERESTIMATE ITS POTENTIAL TO
 ULTIMATELY BECOME A VERY INTENSE TROPICAL CYCLONE.
  
 DESPITE THE LARGE SIZE AND IMPROVED APPEARANCE OF THE TROPICAL
 CYCLONE IN SATELLITE IMAGERY...AND THE CONTINUED COOLING OF THE
 CUMULONIMBUS CLOUD TOPS...IT IS DIFFICULT TO LOCATE THE LLCC IN THE
 INFRARED SATELLITE IMAGERY. THE SATELLITE AGENCIES...PHFO...JTWC
 AND SAB...HAD A RELATIVELY LARGE SPREAD IN THE LOCATIONS OF THE
 LLCC. SCATTEROMETER DATA FROM AN ASCAT PASS AT 0820 UTC SEEMED TO
 INDICATE IT WAS A BIT FURTHER SOUTH THAN EXPECTED. THE CURRENT
 POSITION IS BASED ON A BLEND OF THESE LOCATIONS. THE CURRENT MOTION
 IS 290/12.
 
 THE SATELLITE FIX AGENCIES ALSO HAD A RANGE OF INTENSITY ESTIMATES
 BASED ON SUBJECTIVE DVORAK TECHNIQUES. THE LATEST T-NUMBERS RANGED
 FROM 1.5 TO 2.5. AN EARLIER HIGH RESOLUTION QUIKSCAT PASS FROM 0425
 UTC INDICATED THERE WERE ALREADY A FEW 35 KT WINDS WITHIN 45 NM OF
 THE APPARENT LLCC THAT WERE NOT FLAGGED FOR RAIN CONTAMINATION.
 BASED ON THIS INFORMATION...ALONG WITH THE IMPROVED APPEARANCE OF 
 THE TROPICAL CYCLONE...TROPICAL DEPRESSION THREE-C IS NOW UPGRADED 
 TO A 35 KT TROPICAL STORM. IT HAS RECEIVED THE HAWAIIAN NAME 
 NEKI...WHICH IS NEXT ON THE LIST OF TROPICAL CYCLONE NAMES IN OUR 
 BASIN.
 
 THE LATEST UW/CIMSS VERTICAL WIND SHEAR ANALYSIS FOR THREE-C 
 INDICATES 2 KT FROM 37 DEGREES. NEKI IS SOUTHWEST OF AN UPPER LEVEL 
 RIDGE...AND SOUTHEAST OF AN UPPER LEVEL TROUGH. AS A RESULT...THE 
 CONSENSUS AND INDIVIDUAL TRACK FORECAST MODELS CONTINUE TO INDICATE 
 THAT THREE-C WILL MOVE TOWARD THE WEST NORTHWEST DURING THE NEXT 12 
 TO 24 HOURS...WITH A GRADUAL TURN TOWARD THE NORTHWEST AT A SLIGHTLY 
 SLOWER FORWARD MOTION OVER THE NEXT 36 TO 48 HOURS. THE LATEST TRACK 
 FORECAST WAS NUDGED SLIGHTLY TO THE LEFT OF THE PREVIOUS ONE...AND 
 CLOSELY FOLLOWS THE TVCN...TCON AND GUNA CONSENSUS FORECASTS.
 
 BASED ON THE TRACK FORECAST...NEKI IS EXPECTED TO CONTINUE MOVING
 ACROSS MARGINAL OCEAN HEAT CONTENT VALUES ACCORDING TO THE LATEST
 CIRA ANALYSIS. THE SEA SURFACE TEMPERATURES ARE ALSO EXPECTED TO 
 REMAIN CLOSE TO 29C ALONG THE FORECAST TRACK. THE UW/CIMSS
 INTENSIFICATION FORECAST INDICATES LOW VALUES OF VERTICAL
 WIND SHEAR ALONG THE NEKI/S TRACK. THEREFORE...THESE CONDITIONS ALL
 APPEAR TO BE VERY FAVORABLE FOR INTENSIFICATION. THE LATEST
 INTENSITY FORECAST IS NUDGED TOWARD THE ICON...WHICH BRINGS THE
 SYSTEM TO MINIMAL HURRICANE INTENSITY WITHIN 36 HOURS. NEKI MAY
 ACTUALLY BECOME A HURRICANE SOONER...SINCE THE LATEST SHIPS
 INTENSITY FORECAST INDICATES RAPID INTENSIFICATION IS POSSIBLE.
  
 THREE-C REMAINS FAR SOUTH OF THE MAIN HAWAIIAN ISLANDS EARLY THIS
 MORNING. HOWEVER...BASED ON THE CURRENT FORECAST...ANYONE IN THE
 VICINITY OF JOHNSTON ISLAND NEEDS TO CLOSELY MONITOR FUTURE
 ADVISORIES. THE CURRENT FORECAST TAKES NIKI NEAR THAT ISLAND 
 WEDNESDAY AS A HURRICANE. A HURRICANE WATCH MAY BE NEEDED FOR
 THAT ISLAND LATER TODAY.
   
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      19/1500Z  9.5N 159.6W    35 KT
  12HR VT     20/0000Z 10.5N 161.6W    45 KT
  24HR VT     20/1200Z 12.0N 163.9W    55 KT
  36HR VT     21/0000Z 13.4N 166.0W    65 KT
  48HR VT     21/1200Z 14.8N 168.0W    75 KT
  72HR VT     22/1200Z 16.4N 170.5W    90 KT
  96HR VT     23/1200Z 18.0N 173.0W    90 KT
 120HR VT     24/1200Z 19.6N 175.3W    90 KT
  
 $$
 FORECASTER HOUSTON