WTPA45 PHFO 200856

TCDCP5



HURRICANE OLAF DISCUSSION NUMBER  22

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP192015

1100 PM HST MON OCT 19 2015



LATEST SATELLITE IMAGES INDICATE THAT OLAF CONTINUES ON A RAPID

INTENSIFICATION TREND THAT BEGAN LAST NIGHT. THE EYE HAS WARMED AND

BECOME INCREASINGLY DISTINCT SINCE THE PREVIOUS ADVISORY...WHILE

SURROUNDING EYE WALL TEMPERATURES HAVE BEEN FLUCTUATING. AVAILABLE

DVORAK INTENSITY ESTIMATES RANGED FROM 6.0/115 KT TO 6.5/127 KT...

AND THE INITIAL INTENSITY FOR THIS ADVISORY IS DEEMED TO BE 130 KT

BASED ON THE OBSERVED TRENDS. THIS MAY BE A LITTLE ON THE LOW

SIDE...AS THE EYE CONTINUED TO WARM THROUGH THE TIME THAT THE

ANALYSES WERE CONDUCTED.



TRACKING THE NEARLY 15 NM WIDE EYE OF OLAF OVER THE PAST 6 TO 8

HOURS LEADS TO AN INITIAL MOTION ESTIMATE OF 285/09 KT. LITTLE

OVERALL CHANGE TO THE ONGOING TRACK PHILOSOPHY HAS BEEN PRESENTED

BY THE LATEST GUIDANCE...WITH OLAF EXPECTED TO CONTINUE MOVING

TOWARD THE WEST AND WEST-NORTHWEST ALONG THE SOUTHERN PERIPHERY OF A

DEEP-LAYER RIDGE FOR THE NEXT 24 HOURS OR SO...AND THEN NORTHWEST

TOWARD A DEVELOPING WEAKNESS IN THE RIDGE ON DAY 2 AND 3. ON DAYS 3

THROUGH 5...A SERIES OF FAST-MOVING SHORTWAVE TROUGHS EMBEDDED IN

THE MID-LATITUDE WESTERLIES NORTH OF OLAF ARE EXPECTED TO CREATE A

BREAK IN THE MID-LEVEL RIDGE BETWEEN 145W-150W LONGITUDE. AN

ESPECIALLY STRONG SHORTWAVE APPROACHING OLAF AT THE END OF THE

FORECAST PERIOD IS EXPECTED TO IMPART A MOTION TOWARD THE NORTH-

NORTHEAST. THE RELIABLE TRACK MODELS ARE TIGHTLY CLUSTERED ON THIS

SOLUTION THROUGH THE FORECAST PERIOD...LEADING TO INCREASED

CONFIDENCE THAT OLAF WILL TURN TOWARD THE NORTH...AND REMAIN WELL TO

THE EAST OF THE HAWAIIAN ISLANDS. THE OFFICIAL FORECAST TRACK LIES

VERY CLOSE TO THE PREVIOUS ADVISORY TRACK...AND IS NEAR THE

GFEX...TVCN AND UKMET SOLUTIONS...AND LIES EAST OF THE GFS ON DAYS 3

THROUGH 5.



LATEST UW-CIMSS AND SHIPS ANALYSES INDICATE SHEAR ON THE ORDER OF 5

KT OR LESS...WHILE WATER VAPOR IMAGERY SHOWS OLAF IN AN ENVIRONMENT

CHARACTERIZED BY OUTFLOW CHANNELS TO BOTH THE NORTH AND THE SOUTH.

SOME ADDITIONAL...BUT MODEST...STRENGTHENING IS STILL LIKELY OVER

THE NEXT DAY OR SO AS OLAF WILL REMAIN IN A LIGHT-SHEAR ENVIRONMENT

WITH SSTS OVER 29C. WITH A CYCLONE THIS INTENSE HOWEVER...THERE

COULD BE DIFFICULT TO FORECAST FLUCTUATIONS IN INTENSITY OVER THE

NEXT 1 TO 2 DAYS DUE TO EYEWALL REPLACEMENT CYCLES. THE UPDATED

INTENSITY FORECAST...AFTER ACCOUNTING FOR THE HIGHER THAN EXPECTED

INITIAL CONDITION...FOLLOWS TRENDS PRESENTED BY THE PREVIOUS...AND

INDICATES A PEAK INTENSITY OF 135 KT OVER THE NEXT 24 HOURS. AFTER

THIS TIME...A SLOW WEAKENING IS ANTICIPATED ON DAYS 2 AND 3...WITH A

GREATER RATE OF WEAKENING FORECAST ON DAYS 4 AND 5. THIS WILL OCCUR

AS OLAF MOVES OVER GRADUALLY LOWERING SSTS AND INTO A MODERATE

SOUTHWESTERLY VERTICAL WIND SHEAR REGIME. THE OFFICIAL INTENSITY

FORECAST REMAINS ABOVE THE INTENSITY CONSENSUS...JUST BELOW THE

SHIPS FORECAST...AND CLOSE TO THE LGEM...BUT DOES NOT INDICATE AS

FAST A WEAKENING TREND THAT LGEM DOES ON DAYS 4 AND 5.





FORECAST POSITIONS AND MAX WINDS



INIT  20/0900Z 10.3N 140.4W  130 KT 150 MPH

 12H  20/1800Z 10.9N 141.6W  135 KT 155 MPH

 24H  21/0600Z 11.8N 143.1W  135 KT 155 MPH

 36H  21/1800Z 12.7N 144.5W  130 KT 150 MPH

 48H  22/0600Z 13.7N 145.5W  125 KT 145 MPH

 72H  23/0600Z 16.3N 146.9W  115 KT 135 MPH

 96H  24/0600Z 19.0N 147.0W   95 KT 110 MPH

120H  25/0600Z 21.5N 146.0W   75 KT  85 MPH



$$



FORECASTER BIRCHARD