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