154 
 WTPA45 PHFO 202041
 TCDCP5
 
 HURRICANE OLAF DISCUSSION NUMBER  24
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP192015
 1100 AM HST TUE OCT 20 2015
  
 OLAF SATELLITE PRESENTATION CONTINUES TO SHOW A ROBUST AND HEALTHY
 TROPICAL SYSTEM THIS MORNING...WITH A WELL-DEFINED 15 NM WIDE EYE
 AND A CONCENTRIC RING OF DEEP CONVECTION. THE UNANIMOUS SUBJECTIVE
 DVORAK SATELLITE INTENSITY ESTIMATES OF 6.5...127 KT...FROM ALL
 THREE SATELLITE CENTERS PROMPTS US TO KEEP THE INITIAL INTENSITY AT
 130 KT FOR THIS ADVISORY. 
 
 WHILE INITIAL MOTION IS UNCHANGED AT 285/09 KT FOR THIS
 ADVISORY...OLAF APPEARS TO BE WOBBLING A BIT...WITH SIX HOUR MOTION
 ACTUALLY SLIGHTLY MORE WESTERLY. HOWEVER...SINCE THE 1800 UTC
 ANALYSIS CYCLE...OLAF MOTION APPEARS TO HAVE PICKED UP A MORE
 NORTHERLY COMPONENT ONCE AGAIN. THE OVERALL TRACK GUIDANCE ENVELOPE
 HAS CHANGED LITTLE OVER THE PAST FEW FORECAST CYCLES...WITH ALL
 GUIDANCE SHOWING HIGH CONFIDENCE IN A RECURVING TRACK KEEPING OLAF
 WELL EAST OF THE MAIN HAWAIIAN ISLANDS. HOWEVER...SWELL GENERATED BY
 OLAF WILL AFFECT THE MAIN HAWAIIAN ISLANDS INTO THE
 WEEKEND...PRODUCING SURF THAT WILL BUILD OVER THE NEXT FEW
 DAYS...THEN BE LARGE...POTENTIALLY LIFE-THREATENING AND DAMAGING.
 SEE PRODUCTS ISSUED BY THE FORECAST OFFICE IN HONOLULU FOR DETAILS.
 OLAF WILL GRADUALLY GAIN LATITUDE THROUGH TODAY AND
 WEDNESDAY...SLIDING WESTWARD ALONG THE SOUTHERN FLANK OF DEEP
 RIDGING TO ITS NORTH. A SHORTWAVE TROUGH IS FORECAST TO PASS
 EASTWARD ALONG THE NORTHERN FLANK OF THIS RIDGE WEDNESDAY AND
 THURSDAY...WEAKENING THE RIDGE AND ALLOWING OLAF TO SLIP NORTHWARD
 MORE QUICKLY. A STRONGER TROUGH IS FORECAST TO PASS EASTWARD
 SATURDAY...BREAKING DOWN THE RIDGE AND SCOOPING OLAF NORTHEASTWARD
 OUT OF THE DEEP TROPICS. THE CURRENT TRACK WAS ADJUSTED SLIGHTLY TO
 THE LEFT THROUGH 24 HOURS TO ACCOUNT FOR INITIAL MOTION...THEN
 FOLDED BACK INTO THE GUIDANCE ENVELOPE AFTERWARDS...FOLLOWING THE
 PREVIOUS TRACK AND TVCN CONSENSUS.
 
 SHIPS AND UW-CIMSS INDICATE SHEAR IN THE 6 TO 8 KT
 RANGE...GENERALLY FROM THE WEST TO NORTHWEST. WHILE OUTFLOW DOES
 APPEAR TO BE HINDERED SLIGHTLY TO THE NORTHWEST...SHEAR HAS YET TO
 IMPACT THE CENTRAL STRUCTURE OF THIS SYSTEM. OLAF HAS NEARED ITS
 PEAK INTENSITY AND MOST INTENSITY GUIDANCE SHOWS STEADY WEAKENING
 FROM HERE ON OUT. HOWEVER...SINCE SHIPS INDICATES THAT SHEAR WILL 
 LIKELY REMAIN LOW THROUGH 12 TO 24 HOURS AS THIS SYSTEM MOVES OVER 
 29C WATER...SOME STRENGTHENING IS FORECAST THROUGH 12 HOURS. A SLOW 
 WEAKENING TREND IS FORECAST AFTERWARDS THROUGH DAY THREE...WITH 
 RAPID WEAKENING FORECAST FOR DAYS FOUR AND FIVE AS SHEAR INCREASES 
 TO OVER 20 KT AND OLAF MOVES OVER COOLER WATER. THE WEAKENING TREND 
 MATCHES THAT OF IVCN...BUT IS A LITTLE FASTER THAN SHIPS AND SOME OF 
 THE GLOBAL MODELS. 
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  20/2100Z 10.8N 142.1W  130 KT 150 MPH
  12H  21/0600Z 11.2N 143.4W  135 KT 155 MPH
  24H  21/1800Z 12.2N 144.7W  130 KT 150 MPH
  36H  22/0600Z 13.5N 145.7W  125 KT 145 MPH
  48H  22/1800Z 14.8N 146.3W  115 KT 135 MPH
  72H  23/1800Z 17.5N 147.0W  100 KT 115 MPH
  96H  24/1800Z 20.3N 146.6W   80 KT  90 MPH
 120H  25/1800Z 22.8N 145.1W   60 KT  70 MPH
  
 $$
 FORECASTER POWELL