EPAC: OLAF - Post-Tropical

[supercane4867]

Olaf should feel proud by spinning with Patricia

[galaxy401]

Yeah I was just thinking too about poor Olaf.

[Kingarabian]

Olaf trying to mimic Patricia.

[Kingarabian]

CPHC better upgrade Olaf back to a major hurricane:




UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 23 OCT 2015 Time : 053000 UTC
Lat : 14:38:42 N Lon : 146:15:00 W


CI# /Pressure/ Vmax
6.3 / 943.7mb/122.2kt


Final T# Adj T# Raw T#
6.3 6.7 6.7

[northjaxpro]

Olaf is strengthening again for sure. He is looking impressive in his own right for sure. Check out the deep cold tops within the eyewall. He looks better even since the time I posted on him the last hour /hour and 1/2. He will be a Cat 4 tropical cyclone for sure later today.

[galaxy401]

Meanwhile Olaf is a category 3 again.

[supercane]

WTPA45 PHFO 231444
TCDCP5

HURRICANE OLAF DISCUSSION NUMBER 35
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP192015
500 AM HST FRI OCT 23 2015

A RAGGED 10 NM WIDE EYE EMBEDDED WITHIN AN ASYMMETRIC DEEP
CONVECTIVE RING DESCRIBES THE CENTRAL FEATURE FOR OLAF. SOME
ADDITIONAL BANDING WITHIN THE NORTH AND EAST QUADRANTS GIVES US THE
IMPRESSION THAT OLAF ORGANIZATION HAS IMPROVED SLIGHTLY SINCE LAST
EVENING. SUBJECTIVE DVORAK SATELLITE INTENSITY ESTIMATES ARE
UNCHANGED FROM EARLIER...5.5...102 KT...FROM ALL THREE SATELLITE
CENTERS. HOWEVER...UW-CIMSS ADT INCREASED DRAMATICALLY TO AN
UNREPRESENTATIVE 6.7...132 KT. GIVEN THE SLIGHTLY BETTER OVERALL
SATELLITE PRESENTATION...AND AS A NOD TO THE ADT TREND...WE WILL
ASSIGN 105 KT AS THE INITIAL INTENSITY FOR THIS ADVISORY.

INITIAL MOTION IS JUST EAST OF DUE NORTH...OR 005/08 KT...AS OLAF
CONTINUES MOVING INTO A WEAKNESS IN THE SUBTROPICAL RIDGE FAR
NORTHEAST OF THE MAIN HAWAIIAN ISLANDS. A LARGE NORTHWARD COMPONENT
WILL CONTINUE THROUGH THE FORECAST PERIOD...WITH A PAIR OF TROUGHS
PASSING EASTWARD TO THE NORTH OF OLAF NUDGING THIS SYSTEM EVER MORE
INSISTENTLY TO THE EAST THROUGH DAY FOUR. TRACK GUIDANCE HAS CHANGE
VERY LITTLE THROUGH 96 HOURS. HOWEVER...GFS JOINED ECMWF IN
DEPICTING A SUDDEN SWING TO THE NORTHWEST BETWEEN 96 AND 120
HOURS...DRAGGING CONSENSUS LEFTWARD LATE IN THE FORECAST PERIOD AS
WELL. THIS MAY BE DUE TO BOTH GLOBAL MODELS SEEING A DECAPITATED
OLAF SUDDENLY COMING UNDER THE INFLUENCE OF SHALLOW LOW LEVEL FLOW
ALONG THE SOUTH FLANK OF THE SUBTROPICAL RIDGE AT THAT POINT.
HOWEVER...BOTH GFS AND ECMWF KEEP OLAF RATHER STRONG ON DAYS FOUR
AND FIVE...SO PERHAPS RIDGE STRENGTHENING TO THE NORTH OF OLAF IS
SEEN. EITHER WAY...THE DAY FIVE FORECAST POINT WAS ADJUSTED TO THE
LEFT TO ACCOUNT FOR THIS EFFECT...LEAVING THE REMAINING FORECAST
POINTS PRETTY MUCH INTACT FROM LAST TIME.

SHIPS AND UW-CIMSS CONTINUE TO DISAGREE ON THE AMOUNT OF SHEAR
ACROSS OLAF...RANGING FROM 15 TO 25 KT...RESPECTIVELY. WE ASSUME
THAT THE AMOUNT OF SHEAR PRESENT IS CLOSER TO THE LOWER VALUE SINCE
THE INNER CORE OF OLAF APPEARS TO BE UNAFFECTED. INTENSITY GUIDANCE
SHOWS WEAKENING ACROSS THE BOARD THROUGH THE NEXT FIVE DAYS AS SHEAR
INCREASES AND SSTS DROP...WITH SHIPS DISSIPATING OLAF BY DAY FOUR.
THE GLOBAL MODELS WEAKEN OLAF MUCH MORE SLOWLY...WITH GFS DEPICTING
OLAF STILL AT TROPICAL STORM STRENGTH ON DAY FIVE. WE WILL KEEP THE
SAME STEADY WEAKENING TREND FROM LAST TIME...EXCEPT FOR A BUMP UP TO
95 KT AT 24 HOURS TO ACCOUNT FOR THE INITIAL INTENSITY INCREASE. WE
FORECAST OLAF WILL REMAIN A MINIMAL HURRICANE AT 72 HOURS...THEN
WEAKEN TO A TROPICAL STORM AT 96 AND 120 HOURS.


FORECAST POSITIONS AND MAX WINDS

INIT 23/1500Z 15.9N 146.2W 105 KT 120 MPH
12H 24/0000Z 16.9N 145.9W 100 KT 115 MPH
24H 24/1200Z 18.3N 145.5W 95 KT 110 MPH
36H 25/0000Z 19.5N 144.9W 90 KT 105 MPH
48H 25/1200Z 20.7N 144.1W 85 KT 100 MPH
72H 26/1200Z 23.3N 141.8W 65 KT 75 MPH
96H 27/1200Z 25.8N 137.9W 60 KT 70 MPH
120H 28/1200Z 30.3N 138.0W 45 KT 50 MPH

$$
FORECASTER POWELL

[Hurricanehink]

Looks like Olaf will become the first storm to cross from CPHC to the NHC territory. The last storm to cross 140°W from CPAC was Ema in 1982, when the EPHC was still around.

[Kingarabian]

AJC3 is proud!

[CrazyC83]

Olaf is looking good, I had almost forgotten about him!

[supercane]

WTPA45 PHFO 232100
TCDCP5

HURRICANE OLAF DISCUSSION NUMBER 36
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP192015
1100 AM HST FRI OCT 23 2015

THE SATELLITE PRESENTATION OF OLAF HAS CHANGED LITTLE SINCE THE
PREVIOUS ADVISORY...WITH THE CLOUD-FILLED EYE SURROUNDED BY A
BROKEN RING OF DEEP CONVECTION. RECENT MICROWAVE IMAGERY SHOWS THAT
THE STRUCTURE OF OLAF HAS IMPROVED SOMEWHAT SINCE THIS
TIME YESTERDAY...BUT ALSO HIGHLIGHTS THE BREAKS IN THE EYE WALL
THAT HAVE RECENTLY BEEN ROTATING AROUND THE CENTER. LATEST
SUBJECTIVE DVORAK INTENSITY ESTIMATES FROM PHFO/SAB/PGTW WERE
5.5/102 KT ACROSS THE BOARD...AND THE INITIAL INTENSITY ESTIMATE
FOR THIS ADVISORY HAS BEEN MAINTAINED AT 105 KT.

OLAF IS TRACKING DUE NORTH THIS MORNING...WITH AN INITIAL MOTION OF
360/09 KT. THE SYNOPTIC SETUP FEATURES A MID-LEVEL HIGH CENTERED
EAST OF OLAF...WITH ANOTHER MID-LEVEL HIGH CENTERED JUST WEST OF THE
DATE LINE. THE RIDGE ASSOCIATED WITH DATE LINE HIGH EXTENDS EASTWARD
OVER THE HAWAIIAN ISLANDS...WITH THE EASTERN TERMINUS OF THIS RIDGE
LOCATED JUST NORTHWEST OF OLAF. WATER VAPOR IMAGERY SHOWS A WELL-
DEFINED TROUGH ALOFT DIGGING SOUTHEASTWARD SEVERAL HUNDRED MILES
NORTHWEST OF OLAF. THUS A SOUTHERLY STEERING FLOW PREVAILS OVER
OLAF...PRIMARILY PROVIDED BY THE HIGH TO THE EAST...BUT ALSO
PROVIDED BY SHORTWAVE TROUGHS RIDING AROUND THE MID-LEVEL HIGH TO
THE DISTANT WEST. OVER TIME...THE HIGH TO THE EAST IS EXPECTED TO
SLIDE INTO A POSITION SOUTH OLAF...WHILE SHORTWAVE TROUGHS PASS FROM
WEST TO EAST WELL TO THE NORTH OF OLAF. THIS WILL INDUCE A MOTION
TOWARD THE NORTH-NORTHEAST...AND THEN TOWARD THE NORTHEAST. AT THE
VERY END OF THE FORECAST PERIOD..THE RIDGE CENTERED WEST OF THE DATE
LINE WILL SHIFT EASTWARD...EVENTUALLY BUILDING TO THE NORTH OF OLAF.
GLOBAL MODELS RESPOND BY SLOWING OLAF/S FORWARD MOTION...AND THE
UPDATED OFFICIAL FORECAST FOLLOWS SUIT. THE UPDATED FORECAST TRACK
LIES CLOSE TO THE TVCN AND GFEX...AND IS SLIGHTLY TO THE RIGHT OF
THE PREVIOUS THROUGH 36 HOURS...AND THEN LIES ALONG THE PREVIOUS BY
48 HOURS...BUT INDICATES A SLOWER FORWARD SPEED. THE 96 AND 120 HOUR
UPDATED TRACK FORECAST REPRESENTS A SLOWER FORWARD MOTION THAN
PREVIOUSLY INDICATED.

THE FORECAST TRACK TAKES OLAF OVER STEADILY DECREASING SSTS...WITH
VALUES EXPECTED TO DIMINISH FROM 28C CURRENTLY...TO NEAR 23C BY DAY
5. VERTICAL SHEAR IS FORECAST TO INCREASE OVER THE NEXT 24 HOURS...
PRIMARILY FROM THE SOUTHWEST...AND THEN REMAIN RELATIVELY STRONG /20
TO 30 KT/ THROUGH THE REMAINDER OF THE FORECAST PERIOD. THIS IS
EXPECTED TO LEAD TO STEADY WEAKENING THROUGH THE FORECAST PERIOD.
THE UPDATED INTENSITY FORECAST REPRESENTS A BLEND OF THE PREVIOUS
AND THE INTENSITY CONSENSUS IVCN...BUT REMAINS HIGHER THAN MOST OF
THE INTENSITY GUIDANCE...INCLUDING SHIPS...WHICH INDICATES
DISSIPATION AFTER 72 HOURS. IF GUIDANCE CONTINUES ON CURRENT
TRENDS...THEN THE NEXT FORECAST WILL LIKELY INDICATE A GREATER RATE
OF WEAKENING...ESPECIALLY LATE IN THE FORECAST.


FORECAST POSITIONS AND MAX WINDS

INIT 23/2100Z 17.1N 146.3W 105 KT 120 MPH
12H 24/0600Z 18.2N 145.9W 95 KT 110 MPH
24H 24/1800Z 19.4N 145.3W 85 KT 100 MPH
36H 25/0600Z 20.4N 144.8W 80 KT 90 MPH
48H 25/1800Z 21.6N 144.1W 70 KT 80 MPH
72H 26/1800Z 23.7N 142.4W 55 KT 65 MPH
96H 27/1800Z 25.6N 140.0W 45 KT 50 MPH
120H 28/1800Z 26.6N 139.0W 35 KT 40 MPH

$$
FORECASTER BIRCHARD

[supercane]

WTPA45 PHFO 240257
TCDCP5

HURRICANE OLAF DISCUSSION NUMBER 37
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP192015
500 PM HST FRI OCT 23 2015

THE OVERALL SATELLITE PRESENTATION OF OLAF HAS CHANGED LITTLE SINCE
THE PREVIOUS ADVISORY. SIMILAR TO THIS MORNING...STRONG EYE WALL
CONVECTION CONTINUES TO ROTATE AROUND THE CENTER...WITH BREAKS IN
THE EYE WALL HIGHLIGHTED BY BOTH CONVENTIONAL AND MICROWAVE
IMAGERY. WATER VAPOR IMAGERY SHOWS OUTFLOW BECOMING INCREASINGLY
RESTRICTED IN THE SOUTH AND SOUTHWEST SEMICIRCLES DUE TO
SOUTHWESTERLY SHEAR NEAR 20 KT...WHILE A MID- AND UPPER-LEVEL
SHORTWAVE TROUGH PASSING NORTH OF OLAF APPEARS TO HAVE ENHANCED
OUTFLOW IN THE NORTHERN SEMICIRCLE. SUBJECTIVE DVORAK CURRENT
INTENSITY ESTIMATES FROM PHFO/SAB/PGTW ARE ONCE AGAIN A CONSENSUS
5.5/102 KT...WHILE SATCON FROM UW-CIMSS INDICATED AN INTENSITY NEAR
110 KT. BASED ON THIS DATA...THE INITIAL INTENSITY FOR THIS ADVISORY
HAS BEEN MAINTAINED AT 105 KT.

THE RAGGED AND CLOUD-FILLED EYE OF OLAF HAS BEEN WOBBLING
SIGNIFICANTLY OVER THE PAST 6 TO 12 HOURS AS IT MOVES GENERALLY
NORTHWARD...AND SMOOTHING OUT THE WOBBLES YIELDS AN INITIAL MOTION
OF 015/09 KT FOR THIS ADVISORY. OVERALL TRACK FORECAST PHILOSOPHY
REMAINS GENERALLY THE SAME HAS BEEN RECENTLY PRESENTED...BUT
GLOBAL MODELS HAVE BEEN TRENDING TOWARD A WEAKER STEERING FLOW AND
A SLOWER FORECAST FORWARD MOTION. GENERALLY SPEAKING...OLAF IS
FORECAST TO TRACK TOWARD THE NORTH-NORTHEAST THROUGH DAY 4...WITH
INCREASED UNCERTAINTY SURROUNDING THE DAY 5 POSITION AND MOTION.

THE CURRENT SYNOPTIC SETUP FEATURES A MID-LEVEL HIGH CENTERED EAST
OF OLAF...WITH ANOTHER MID-LEVEL HIGH CENTERED JUST WEST OF THE DATE
LINE. THE RIDGE ASSOCIATED WITH THE DATE LINE HIGH EXTENDS EASTWARD
TO NEAR THE HAWAIIAN ISLANDS...WHILE A SIGNIFICANT BREAK IN THE
RIDGE EXISTS NORTH OF OLAF. SHORTWAVE TROUGHS EMBEDDED IN THE
MID-LATITUDE WESTERLIES ARE MAINTAINING THE BREAK IN THE
RIDGE...WITH A FAST-MOVING TROUGH CURRENTLY PASSING NORTH OF OLAF.
THIS TROUGH IS FORECAST TO LIFT RAPIDLY NORTHEASTWARD OVER THE NEXT
12 TO 24 HOURS...AND THE PRIMARY STEERING FEATURE WILL THEN BECOME
THE HIGH EAST OF OLAF...WHICH WILL MOVE TO A POSITION SOUTHEAST...
AND THEN SOUTH...OF OLAF THROUGH THE WEEKEND. ANOTHER SHORTWAVE
PASSING NORTH OF OLAF OVER THE WEEKEND WAS EARLIER FORECAST TO DIG
FURTHER SOUTHEAST THAN RECENT GUIDANCE SUGGESTS. WITH THIS TROUGH
NOW EXPECTED TO BE FARTHER NORTH...THE PRIMARY STEERING MECHANISM
WILL BE THE RIDGE SOUTH OF OLAF. THE TRACK FORECAST AND GUIDANCE HAS
RESPONDED BY SLOWING THE FORWARD SPEED OF OLAF...ESPECIALLY IN THE 3
TO 5 DAY RANGE. AT THE END OF THE FORECAST PERIOD...THE RIDGE
CURRENTLY NEAR THE DATE LINE IS EXPECTED TO SHIFT RAPIDLY EASTWARD
AND BUILD NORTH OF OLAF. GLOBAL MODELS INDICATE THAT THIS WILL CAUSE
OLAF TO BRIEFLY BECOME NEARLY STATIONARY...BEFORE MAKING A TURN BACK
TOWARD THE WEST. THE UPDATED OFFICIAL FORECAST INDICATES VERY LITTLE
CHANGE IN FORECAST POSITIONS BETWEEN DAYS 4 AND 5 AS THIS OCCURS.
OTHERWISE...THE UPDATED TRACK FORECAST LIES CLOSE TO THE
PREVIOUS...AND CLOSELY FOLLOWS THE TVCN AND FSSE GUIDANCE...BUT IS
NOT AS FAST IN TURNING OLAF BACK TOWARD THE WEST ON DAY 5.

THE FORECAST TRACK TAKES OLAF OVER STEADILY DECREASING SSTS...WITH
VALUES EXPECTED TO DIMINISH FROM JUST BELOW 28C CURRENTLY...TO NEAR
25C BY DAY 5. VERTICAL SHEAR IS FORECAST TO INCREASE OVER THE NEXT
12 HOURS...AS THE AFOREMENTIONED SHORTWAVE PASSES NORTH OF OLAF...
AND THEN FLUCTUATE THROUGH THE REMAINDER OF THE FORECAST PERIOD AS
A DYNAMIC PATTERN ALOFT DEVELOPS. DESPITE RECENT TRENDS OF
MAINTAINING STRENGTH...FAIRLY STEADY WEAKENING IS ANTICIPATED
THROUGH THE FORECAST PERIOD. THE UPDATED INTENSITY FORECAST
REPRESENTS A BLEND OF THE PREVIOUS AND THE INTENSITY CONSENSUS
IVCN...BUT REMAINS HIGHER THAN MOST OF THE GUIDANCE...INCLUDING
SHIPS...WHICH INDICATES DISSIPATION AFTER 72 HOURS.

A WELL-PLACED ASCAT PASS AROUND 1920Z WAS UTILIZED TO FINE-TUNE THE
34 AND 50 KT WIND RADII...WITH THE PRIMARY EFFECT BEING AN
EXPANSION OF THE RADII...ESPECIALLY IN THE SOUTH SEMICIRCLE.


FORECAST POSITIONS AND MAX WINDS

INIT 24/0300Z 18.2N 145.8W 105 KT 120 MPH
12H 24/1200Z 19.0N 145.4W 95 KT 110 MPH
24H 25/0000Z 20.2N 144.9W 80 KT 90 MPH
36H 25/1200Z 21.3N 144.3W 70 KT 80 MPH
48H 26/0000Z 22.2N 143.7W 60 KT 70 MPH
72H 27/0000Z 24.0N 141.7W 50 KT 60 MPH
96H 28/0000Z 25.5N 139.5W 40 KT 45 MPH
120H 29/0000Z 26.0N 139.5W 30 KT 35 MPH

$$

FORECASTER BIRCHARD

[cycloneye]

HURRICANE OLAF DISCUSSION NUMBER 38
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP192015
1100 PM HST FRI OCT 23 2015

THE DVORAK SUBJECTIVE ESTIMATES FROM HFO...JTWC AND SAB WERE ALL
5.5/102 KT...UNCHANGED FROM SIX HOURS AGO. THE UW-CIMSS OBJECTIVE
ESTIMATE WAS 5.9/112.4 KT. OLAF HAS MAINTAINED A RAGGED EYE OVER THE
PAST 6 HOURS. THE AREA OF COLD CLOUDS SURROUNDING THE CENTER HAS
BECOME A BIT MORE STRETCHED OUT TOWARDS THE NORTH. THE INITIAL
INTENSITY FOR THIS ADVISORY WILL BE KEPT AT 105 KT.

THE INITIAL MOTION FOR THIS ADVISORY IS EXPECTED TO CONTINUE 005/08
KT WITH GOOD CONFIDENCE IN RECENT CENTER POSITIONS. OLAF IS MOVING
THROUGH A WEAKNESS IN THE SUBTROPICAL RIDGE WITH A SHORT-WAVE TROUGH
PASSING EASTWARD FAR NORTH OF THE HURRICANE. OLAF IS FORECAST TO
CURVE SLIGHTLY TOWARD THE NORTHEAST WITH A SLIGHT SLOWING OF ITS
FORWARD MOTION OVER THE NEXT COUPLE OF DAYS...THEN START MOVING
FASTER TOWARD THE NORTHEAST. THE TRUSTED TRACK GUIDANCE IS IN GOOD
AGREEMENT FOR THE NEXT FEW DAYS. THE CURRENT FORECAST REMAINS CLOSE
TO THE GUIDANCE AND THE PREVIOUS TRACK.

SHIPS SHOWS 27 KT OF VERTICAL WIND SHEAR...VWS...FROM THE SOUTHWEST
WHILE UW-CIMSS SHOWS 36 KT FROM THE SOUTH SOUTHWEST. OLAF IS OVER 27
DEGREE CELSIUS WATER WITH THE SEA SURFACE TEMPERATURE...SST...
EXPECTED TO DROP SLIGHTLY TO 25.5 DEGREES ALONG THE FORECAST TRACK.
CONTINUING VWS AND DECREASING SST ARE EXPECTED TO STEADILY WEAKEN
OLAF OVER THE NEXT FEW DAYS.

THE FORECAST BECOMES MORE PROBLEMATICAL AFTER ABOUT 72 HOURS WHEN
THE GUIDANCE SHOWS THE SUBTROPICAL RIDGE BUILDING NORTH OF OLAF.
THAT CAN BE EXPECTED TO CAUSE OLAF TO TAKE A SHARP TURN TOWARD THE
WEST AND WEAKEN RAPIDLY. TIMING THE TURN TO THE WEST MAY BE
DIFFICULT SINCE THE TURN MAY BE QUITE SUDDEN AND SINCE THERE IS
QUITE A BIT OF SPREAD IN THE MODEL GUIDANCE REGARDING EXACTLY WHEN
AND WHERE IT WILL OCCUR. THE CURRENT FORECAST SHOWS THE TURN TAKING
PLACE WEDNESDAY MORNING...BUT THAT MAY NEED TO BE ADJUSTED IN LATER
FORECAST PACKAGES.



FORECAST POSITIONS AND MAX WINDS

INIT 24/0900Z 18.7N 145.6W 105 KT 120 MPH
12H 24/1800Z 19.6N 145.1W 95 KT 110 MPH
24H 25/0600Z 20.7N 144.4W 80 KT 90 MPH
36H 25/1800Z 21.8N 143.7W 70 KT 80 MPH
48H 26/0600Z 22.9N 142.8W 60 KT 70 MPH
72H 27/0600Z 24.8N 140.2W 50 KT 60 MPH
96H 28/0600Z 25.5N 139.5W 40 KT 45 MPH
120H 29/0600Z 26.0N 141.0W 30 KT 35 MPH

$$
FORECASTER DONALDSON

[wxmann_91]

This would be a kind of ridiculous NHC-CPHC-NHC-CPHC swap if it verified:

[cycloneye]

HURRICANE OLAF DISCUSSION NUMBER 39
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP192015
500 AM HST SAT OCT 24 2015

THE DVORAK SUBJECTIVE ESTIMATES FROM JTWC AND SAB WERE 5.0/90 KT...
AND 5.5/102 KT FROM HFO. THE UW-CIMSS OBJECTIVE ESTIMATE WAS
6.0/115.0 KT. THE EYE HAS DISAPPEARED OVER THE PAST 6 HOURS...BUT
VERY COLD CLOUDS STILL COVER THE CENTER. THE INITIAL INTENSITY FOR
THIS ADVISORY WILL BE KEPT AT 105 KT.

THE INITIAL MOTION FOR THIS ADVISORY IS 030 DEGREES AT 7 KT WITH
FAIR CONFIDENCE IN RECENT CENTER POSITIONS. OLAF IS MOVING
THROUGH A WEAKNESS IN THE SUBTROPICAL RIDGE WHILE A SHORT-WAVE
TROUGH MOVES EASTWARD FAR NORTH OF THE HURRICANE. OLAF IS FORECAST
TO CURVE SLIGHTLY TOWARD THE NORTHEAST OVER THE NEXT COUPLE OF DAYS.
THE TRACK GUIDANCE REMAINS IN GOOD AGREEMENT FOR THE NEXT FEW DAYS.
THE CURRENT FORECAST REMAINS CLOSE TO THE GUIDANCE AND THE PREVIOUS
TRACK.

SHIPS SHOWS 31 KT OF VERTICAL WIND SHEAR...VWS...FROM THE
SOUTHWEST...WHILE UW-CIMSS SHOWS 36 KT FROM THE SOUTHWEST.
OLAF REMAINS OVER 27 DEGREE CELSIUS WATER WITH THE SEA SURFACE
TEMPERATURE...SST...EXPECTED TO DROP SLIGHTLY TO 25.5 DEGREES ALONG
THE FORECAST TRACK. CONTINUING VWS AND DECREASING SST ARE EXPECTED
TO STEADILY WEAKEN OLAF OVER THE NEXT FEW DAYS.

THE FORECAST BECOMES MORE PROBLEMATICAL AFTER ABOUT 72 HOURS WHEN
THE GUIDANCE SHOWS THE SUBTROPICAL RIDGE BUILDING NORTH OF OLAF.
THAT CAN BE EXPECTED TO CAUSE OLAF TO TAKE A SHARP TURN TOWARD THE
WEST AND WEAKEN RAPIDLY. TIMING THE TURN TO THE WEST MAY BE
DIFFICULT SINCE THE TURN MAY BE QUITE ABRUPT. THE MODEL GUIDANCE
HAS BECOME MORE CONSISTENT DEPICTING THE DIRECTIONAL CHANGE...BUT
THERE IS STILL QUITE A BIT OF SPREAD IN THE GUIDANCE. THIS FORECAST
HAS A SHARPER TURN TO THE WEST AND SHOWS OLAF MOVING FASTER AFTER
THE TURN.


FORECAST POSITIONS AND MAX WINDS

INIT 24/1500Z 19.3N 145.3W 105 KT 120 MPH
12H 25/0000Z 20.2N 144.7W 90 KT 105 MPH
24H 25/1200Z 21.3N 143.9W 80 KT 90 MPH
36H 26/0000Z 22.2N 143.2W 65 KT 75 MPH
48H 26/1200Z 23.4N 142.2W 55 KT 65 MPH
72H 27/1200Z 25.0N 140.0W 40 KT 45 MPH
96H 28/1200Z 26.0N 140.0W 35 KT 40 MPH
120H 29/1200Z 26.0N 144.0W 30 KT 35 MPH

$$
FORECASTER DONALDSON

[cycloneye]

Keeps adding ACE.

Philip Klotzbach ‏@philklotzbach · 15m15 minutes ago
#Olaf is now in 2nd place for ACE generated by a NE Pac (to 180W) TC forming after 1 Oct, trailing only Trudy (1990)

[supercane]

WTPA45 PHFO 242058
TCDCP5

HURRICANE OLAF DISCUSSION NUMBER 40
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP192015
1100 AM HST SAT OCT 24 2015

OLAF IS WEAKENING IN THE FACE OF SOUTHWESTERLY VERTICAL WIND
SHEAR...ESTIMATED TO BE NEAR 30 KT...AND THE EYE IS NO LONGER
VISIBLE IN CONVENTIONAL SATELLITE IMAGERY. A 1615Z WINDSAT PASS
HOWEVER INDICATED AN EYE-LIKE FEATURE WITH BREAKS IN THE EYE WALL IN
THE SOUTHEAST SEMICIRCLE. SUBJECTIVE DVORAK CURRENT INTENSITY
ESTIMATES WERE 5.0/90 KT FROM PHFO/SAB/PGTW...WHILE SATCON FROM
UW-CIMSS IS ALSO TRENDING DOWN...WITH THE LATEST AVAILABLE INTENSITY
ESTIMATE NEAR 95 KT. THE INITIAL INTENSITY USED FOR THIS ADVISORY IS
A SOMEWHAT CONSERVATIVE 95 KT.

LATEST ANALYSES FEATURE A NORTHEAST TO SOUTHWEST ORIENTED
DEEP-LAYER RIDGE TO THE EAST OF OLAF...AND AN EAST TO WEST ORIENTED
RIDGE CENTERED NEAR THE DATE LINE. OLAF IS MOVING NORTH-
NORTHEAST...030/07 KT...INTO A SIGNIFICANT BREAK IN THE RIDGE...AND
INCREASINGLY INTO THE MID-LATITUDE WESTERLIES. NORTH OF THE DATE
LINE RIDGE...A FAST-MOVING SHORTWAVE TROUGH IN THE WESTERLIES ALOFT
IS SEEN MOVING EAST-SOUTHEAST NEAR 55 MPH. THIS FEATURE IS
RESPONSIBLE FOR INTRODUCING INCREASED UNCERTAINTY TO THE TRACK
FORECAST FOR OLAF...ESPECIALLY IN LATER FORECAST PERIODS. WHEREAS
RECENT MODEL ITERATIONS TRENDED TOWARD A WEAKER TROUGH...THE LATEST
GUIDANCE IS NOW INDICATING A DEEPER TROUGH TAKING OLAF FURTHER EAST
AT A FASTER RATE OF SPEED BEFORE THE TROUGH LIFTS. THE DATE LINE
RIDGE IS STILL EXPECTED TO SHIFT RAPIDLY EAST AND BUILD NORTH OF
OLAF AS THE TROUGH LIFTS OUT...INDUCING A TURN TOWARD THE
WEST...WITH SIGNIFICANT UNCERTAINTY SURROUNDING THE TIMING AND
LOCATION OF THIS TURN. DUE TO THE LACK OF MODEL CONSISTENCY...THE
OFFICIAL FORECAST REPRESENTS A BLEND OF THE PREVIOUS TRACK FORECAST
AND THE LATEST TVCN AND FSSE CONSENSUS GUIDANCE...TAKING OLAF NORTH-
NORTHEASTWARD THROUGH DAY 3 BEFORE TURNING IT SHARPLY BACK TOWARD
THE WEST.

STRONG SOUTHWESTERLY SHEAR IS FORECAST TO DIMINISH SOMEWHAT IN THE
SHORT TERM AS A SHORTWAVE TROUGH NORTH OF OLAF LIFTS OUT...AND
BEFORE A SECOND SHORTWAVE /DISCUSSED ABOVE/ ARRIVES IN ABOUT 36
HOURS. THE FORECAST TRACK TAKES OLAF OVER STEADILY DECREASING SSTS
THROUGH DAY 3...AFTER WHICH TIME IT IS EXPECTED TO BE OVER SSTS
BETWEEN 25C AND 26C. THE UPDATED INTENSITY FORECAST CLOSELY FOLLOWS
GUIDANCE PROVIDED BY THE INTENSITY CONSENSUS IVCN...AND INDICATES
THAT RAPID WEAKENING IN THE FIRST 24 HOURS OF THE FORECAST WILL BE
FOLLOWED BY A SLOWER RATE OF WEAKENING. SHIPS RESPONDS TO THE
DECREASING SSTS AND PERSISTENT SHEAR BY DISSIPATING OLAF AFTER 72
HOURS. THE OFFICIAL FORECAST MAINTAINS OLAF AS A TROPICAL
DEPRESSION AS IT MOVES WEST ON DAYS 4 AND 5...BUT THERE IS
CONSIDERABLE UNCERTAINTY AS TO WHETHER OLAF WILL BE ABLE TO SURVIVE
THE MODERATE TO STRONG SOUTHWESTERLY SHEAR IT ENCOUNTERS BEFORE
THAT TIME.


FORECAST POSITIONS AND MAX WINDS

INIT 24/2100Z 19.8N 145.0W 95 KT 110 MPH
12H 25/0600Z 20.8N 144.5W 80 KT 90 MPH
24H 25/1800Z 21.9N 143.9W 70 KT 80 MPH
36H 26/0600Z 23.2N 142.8W 60 KT 70 MPH
48H 26/1800Z 24.5N 141.1W 50 KT 60 MPH
72H 27/1800Z 26.1N 138.5W 35 KT 40 MPH
96H 28/1800Z 26.5N 140.0W 30 KT 35 MPH
120H 29/1800Z 26.5N 142.5W 30 KT 35 MPH

$$

FORECASTER BIRCHARD

[supercane]

WTPA45 PHFO 250258
TCDCP5

HURRICANE OLAF DISCUSSION NUMBER 41
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP192015
500 PM HST SAT OCT 24 2015

OLAF CONTINUES TO BE WEAKENED BY STRONG SOUTHWESTERLY VERTICAL WIND
SHEAR NEAR 30 KT...BUT REMAINS AT HURRICANE STRENGTH THIS
AFTERNOON. WHILE A CLOUD-FILLED EYE IS BARELY DISCERNIBLE IN VISIBLE
IMAGERY...AVAILABLE MICROWAVE IMAGES INDICATE THAT THE EYE STILL
EXISTS...HIGHLIGHTED MOST RECENTLY BY 2345Z MHS AND 0110Z SSMIS
OVERPASSES. THESE PASSES INDICATED SIGNIFICANT EYE WALL BREAKS IN
THE SOUTHERN SEMICIRCLE...AS WELL AS MODEST TILTING TOWARD THE
NORTHEAST WITH HEIGHT. SUBJECTIVE DVORAK CURRENT INTENSITY ESTIMATES
RANGED FROM 4.5/77 KT FROM PHFO TO 5.0/90 KT FROM SAB/PGTW...AND THE
INITIAL INTENSITY FOR THIS ADVISORY HAS BEEN LOWERED TO 85 KT.

OLAF IS MOVING TOWARD THE NORTH-NORTHEAST...WITH THE CURRENT MOTION
VECTOR ESTIMATED TO BE 030/10 KT. THE CYCLONE LIES BETWEEN A
NORTHEAST TO SOUTHWEST ORIENTED DEEP-LAYER RIDGE TO THE SOUTHEAST...
AND AN EAST TO WEST ORIENTED RIDGE CENTERED WELL TO THE WEST...NEAR
THE INTERNATIONAL DATE LINE. THE RECENT OBSERVED MOTION HAS OLAF
MOVING ON A TRAJECTORY THAT IS FASTER AND TO THE RIGHT OF THE
PREVIOUS FORECAST TRACK...AND INCREASINGLY INTO THE MID-LATITUDE
WESTERLIES NORTH OF THE RIDGE AXIS. AN APPROACHING POTENT MID-LEVEL
SHORTWAVE TROUGH PASSING NORTH OF THE MAIN HAWAIIAN ISLANDS IS NOW
EXPECTED TO BE SUFFICIENTLY STRONG TO COMPLETELY DISRUPT THE
CIRCULATION OF OLAF BY DAY 3. ON DAYS 4 AND 5...THE RIDGE NEAR THE
DATE LINE IS EXPECTED TO SHIFT RAPIDLY EAST AND BUILD NORTH OF OLAF
IN RESPONSE TO THE SHORTWAVE TROUGH LIFTING NORTHEASTWARD. THIS WILL
INDUCE A TURN TOWARD THE WEST AS OLAF WEAKENS TO A SHALLOW REMNANT
LOW STEERED BY THE RETURNING TRADE WIND FLOW. THE UPDATED TRACK
FORECAST CLOSELY FOLLOWS THE PREVIOUS AND THE TVCN CONSENSUS THROUGH
DAY 3...AND THEN REPRESENTS A BLEND BETWEEN THE PREVIOUS AND THE
TVCN ON DAYS 4 AND 5.

AS SOUTHWESTERLY VERTICAL WIND SHEAR WILL REMAIN RELATIVELY HIGH
OVER THE NEXT COUPLE OF DAYS WHILE OLAF MOVES OVER COOLER SSTS...
OLAF IS NOT EXPECTED TO REMAIN AT HURRICANE STRENGTH FOR MUCH
LONGER. THE UPDATED INTENSITY FORECAST IS VERY CLOSE TO THE IVCN
INTENSITY CONSENSUS...AND HAS EXPEDITED THE FORECAST DEMISE OF
OLAF...WHICH IS EXPECTED TO BECOME A TROPICAL STORM ON SUNDAY. AS
MENTIONED ABOVE...SHEAR ASSOCIATED WITH A STRONG SHORTWAVE TROUGH
APPROACHING OLAF FROM THE NORTHWEST IS EXPECTED TO LEAD TO POST-
TROPICAL REMNANT LOW STATUS BY WEDNESDAY. THIS IS STILL NOT AS
AGGRESSIVE AS SHIPS GUIDANCE...WHICH INDICATES DISSIPATION OF OLAF
BY DAY 3.


FORECAST POSITIONS AND MAX WINDS

INIT 25/0300Z 20.7N 144.3W 85 KT 100 MPH
12H 25/1200Z 21.9N 143.6W 70 KT 80 MPH
24H 26/0000Z 23.0N 142.8W 60 KT 70 MPH
36H 26/1200Z 24.2N 141.5W 50 KT 60 MPH
48H 27/0000Z 25.2N 139.7W 40 KT 45 MPH
72H 28/0000Z 26.6N 137.0W 30 KT 35 MPH
96H 29/0000Z 26.0N 139.5W 30 KT 35 MPH...POST-TROP/REMNT LOW
120H 30/0000Z 25.5N 143.5W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$

FORECASTER BIRCHARD

[supercane]

WTPA45 PHFO 250859
TCDCP5

HURRICANE OLAF DISCUSSION NUMBER 42
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP192015
1100 PM HST SAT OCT 24 2015

OLAF REMAINS RATHER WELL-ORGANIZED THIS EVENING...WITH INFRARED
SATELLITE IMAGERY REVEALING A RAGGED BUT CLOUD-FREE EYE DURING THE
PAST FEW HOURS. 0327Z WINDSAT AND 0423Z SSMS MICROWAVE PASSES ALSO
DEPICTED A WELL-DEFINED EYE. HOWEVER...DEEP CONVECTION AROUND THE
EYE HAS WEAKENED INTERMITTENTLY DURING THE EVENING...AND THE EYE HAS
BEEN OPEN TO THE SOUTH AT TIMES. SUBJECTIVE DVORAK CURRENT INTENSITY
ESTIMATES CAME IN AT 4.5/77 KT FROM ALL THREE AGENCIES...WHILE THE
UW-CIMSS ADT CURRENT INTENSITY ESTIMATE REMAINS SIGNIFICANTLY
STRONGER AT 5.3/97 KT. THE INITIAL INTENSITY FOR THIS ADVISORY HAS
BEEN LOWERED TO 80 KT.

OLAF APPEARS TO HAVE SLOWED DOWN AND TURNED SLIGHTLY TO THE RIGHT
DURING THE EVENING...AND HAVE USED A LONGER-TERM 12 HOUR MOTION OF
035/07 KT FOR THIS ADVISORY. THE CYCLONE LIES BETWEEN A NORTHEAST
TO SOUTHWEST ORIENTED DEEP-LAYER RIDGE TO THE SOUTHEAST...AND AN
EAST TO WEST ORIENTED RIDGE CENTERED WELL TO THE WEST...NEAR
THE INTERNATIONAL DATE LINE. WATER VAPOR IMAGERY SHOWS A POTENT
MID-LATITUDE TROUGH MOVING QUICKLY EASTWARD TO THE NORTH OF
HAWAII...AND THIS TROUGH IS EXPECTED TO EXERT AN INCREASING
INFLUENCE ON OLAF THROUGH AT LEAST THE NEXT 48 HOURS...WITH THE
CYCLONE MOVING MORE QUICKLY TOWARD THE NORTHEAST. GUIDANCE DIVERGES
SIGNIFICANTLY AT 72 HOURS AND BEYOND...WITH THE GFS AND GFDL
CONTINUING TO ACCELERATE OLAF OFF TO THE NORTHEAST AS IT BECOMES
FULLY ENTRAINED IN THE MID-LATITUDE TROUGH...WHILE MOST OF THE OTHER
MODELS INCLUDING THE ECMWF TURN THE WEAKENING CYCLONE BACK TOWARD
THE SOUTHWEST...TO THE SOUTH OF A BUILDING DEEP-LAYER RIDGE OVER THE
NORTHEAST PACIFIC. THE GUIDANCE ENVELOPE DID SHIFT SIGNIFICANTLY
EASTWARD WITH THIS CYCLE. THE NEW OFFICIAL FORECAST REPRESENTS A
BLEND BETWEEN THE PREVIOUS TRACK AND THE TVCN MODEL CONSENSUS
THROUGH 48 HOURS...THEN IS MOST SIMILAR TO THE ECMWF AT 72 HOURS AND
BEYOND.

SATELLITE IMAGERY INDICATES THAT WEST/SOUTHWEST VERTICAL WIND SHEAR
CONTINUES TO IMPACT OLAF...WITH OUTFLOW RESTRICTED IN THOSE
QUADRANTS. UW-CIMSS AND SHIPS SHEAR MAGNITUDE ESTIMATES RANGE FROM
21 TO 27 KT...AND THE SHEAR SHOULD REMAIN ROUGHLY THE SAME OR
INCREASE SOMEWHAT DURING THE NEXT 48 HOURS AS THE MID-LATITUDE
TROUGH MOVES CLOSER TO THE CYCLONE. OLAF WILL ALSO BE MOVING OVER
COOLER SEA SURFACE TEMPERATURES AND DECREASING OCEAN HEAT CONTENT
VALUES DURING THE NEXT FEW DAYS. STEADY WEAKENING IS FORECAST. THE
OFFICIAL INTENSITY FORECAST IS CLOSE TO THE IVCN CONSENSUS...AND
REPRESENTS A COMPROMISE BETWEEN THE FASTER WEAKENING RATES DEPICTED
BY THE SHIPS AND LGEM...AND THE SLOWER RATES SHOWN BY MOST OF THE
DYNAMICAL MODELS. WE CONTINUE TO SHOW OLAF AS A POST-TROPICAL
REMNANT LOW AT DAYS 4 AND 5.


FORECAST POSITIONS AND MAX WINDS

INIT 25/0900Z 21.2N 143.8W 80 KT 90 MPH
12H 25/1800Z 22.1N 143.2W 70 KT 80 MPH
24H 26/0600Z 23.6N 141.9W 60 KT 70 MPH
36H 26/1800Z 25.0N 140.0W 50 KT 60 MPH
48H 27/0600Z 26.7N 137.5W 40 KT 45 MPH
72H 28/0600Z 28.0N 134.0W 30 KT 35 MPH
96H 29/0600Z 26.5N 133.5W 30 KT 35 MPH...POST-TROP/REMNT LOW
120H 30/0600Z 24.5N 140.0W 25 KT 30 MPH...POST-TROP/REMNT LOW

$$
FORECASTER JACOBSON

[supercane]

WTPA45 PHFO 251450
TCDCP5

HURRICANE OLAF DISCUSSION NUMBER 43
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP192015
500 AM HST SUN OCT 25 2015

OLAF CONTINUES TO HOLD ITS OWN...WITH INFRARED SATELLITE IMAGERY
SHOWING A RAGGED BUT PERSISTENT EYE DURING THE NIGHT. OVERALL
CONVECTIVE COVERAGE HAS DIMINISHED TO THE WEST AND SOUTH OF THE
CENTER...BUT THE CENTRAL CORE OF THE SYSTEM REMAINS INTACT AT THIS
TIME. SUBJECTIVE DVORAK CURRENT INTENSITY ESTIMATES REMAIN 4.5/77 KT
FROM ALL THREE AGENCIES...WHILE THE UW-CIMSS ADT CURRENT INTENSITY
ESTIMATE REMAINS MUCH STRONGER AT 5.5/102 KT. AN EARLIER ASCAT PASS
ACROSS THE WESTERN HALF OF THE CYCLONE DID FIND SOME HURRICANE FORCE
WIND BARBS...AND THE WIND RADII WERE ADJUSTED BASED ON THE ASCAT
DATA. THE INITIAL INTENSITY FOR THIS ADVISORY WILL REMAIN AT 80 KT.

OLAF HAS CONTINUED ON A STEADY NORTHEAST COURSE DURING THE NIGHT...
AND THE INITIAL MOTION ESTIMATE IS 035/07 KT. THE CYCLONE LIES
BETWEEN A NORTHEAST TO SOUTHWEST ORIENTED DEEP-LAYER RIDGE TO THE
SOUTHEAST...AND AN EAST TO WEST ORIENTED RIDGE CENTERED WELL TO THE
WEST...NEAR THE INTERNATIONAL DATE LINE. WATER VAPOR IMAGERY SHOWS A
POTENT MID-LATITUDE TROUGH MOVING QUICKLY EASTWARD TO THE NORTH OF
HAWAII...AND THIS TROUGH IS EXPECTED TO EXERT AN INCREASING
INFLUENCE ON OLAF THROUGH AT LEAST THE NEXT 48 HOURS...WITH THE
CYCLONE MOVING MORE QUICKLY TOWARD THE NORTHEAST. GUIDANCE DIVERGES
SIGNIFICANTLY AT 72 HOURS AND BEYOND...WITH THE GFS AND GFDL
CONTINUING TO ACCELERATE OLAF OFF TO THE NORTHEAST AS IT BECOMES
FULLY ENTRAINED IN THE MID-LATITUDE TROUGH...WHILE MOST OF THE OTHER
MODELS INCLUDING THE ECMWF TURN THE WEAKENING CYCLONE BACK TOWARD
THE SOUTHWEST...TO THE SOUTH OF A BUILDING DEEP-LAYER RIDGE OVER THE
NORTHEAST PACIFIC. THE NEW OFFICIAL FORECAST REPRESENTS A BLEND
BETWEEN THE PREVIOUS TRACK AND THE TVCN MODEL CONSENSUS THROUGH 48
HOURS...THEN IS NUDGED CLOSER TO THE ECMWF AT 72 HOURS AND BEYOND.

SATELLITE IMAGERY INDICATES THAT WESTERLY VERTICAL WIND SHEAR
CONTINUES TO IMPACT OLAF...WITH OUTFLOW RESTRICTED TO THE WEST
AND SOUTH. UW-CIMSS AND SHIPS SHEAR MAGNITUDE ESTIMATES RANGE FROM
20 TO 28 KT...AND THE SHEAR IS FORECAST TO REMAIN ROUGHLY THE SAME
OR INCREASE SOMEWHAT DURING THE NEXT 48 HOURS AS THE MID-LATITUDE
TROUGH MOVES CLOSER TO THE CYCLONE. OLAF WILL ALSO BE MOVING OVER
COOLER SEA SURFACE TEMPERATURES AND DECREASING OCEAN HEAT CONTENT
VALUES DURING THE NEXT FEW DAYS...AND MODEL OUTPUT AS WELL AS
SATELLITE DATA SUGGEST THAT THE CYCLONE WILL BE IMPACTED BY
SIGNIFICANT MID LEVEL DRY AIR. THE OFFICIAL INTENSITY FORECAST
REMAINS CLOSE TO THE IVCN CONSENSUS...AND SHOWS A SLOWER WEAKENING
TREND THAN PREVIOUSLY INDICATED DURING THE FIRST 24 HOURS DUE TO THE
RECENT RESILIENCE OF THE CYCLONE. THIS REPRESENTS A COMPROMISE
BETWEEN THE FASTER WEAKENING RATES DEPICTED BY THE SHIPS AND
LGEM...AND THE SLOWER RATES SHOWN BY MOST OF THE DYNAMICAL MODELS.
WE CONTINUE TO SHOW OLAF AS A POST-TROPICAL REMNANT LOW AT DAY 4...
AND HAVE FORECAST DISSIPATION AT DAY 5.


FORECAST POSITIONS AND MAX WINDS

INIT 25/1500Z 21.6N 143.6W 80 KT 90 MPH
12H 26/0000Z 22.8N 142.7W 75 KT 85 MPH
24H 26/1200Z 24.5N 140.8W 65 KT 75 MPH
36H 27/0000Z 26.2N 138.4W 50 KT 60 MPH
48H 27/1200Z 28.1N 135.3W 40 KT 45 MPH
72H 28/1200Z 29.0N 132.0W 30 KT 35 MPH
96H 29/1200Z 25.5N 134.0W 30 KT 35 MPH...POST-TROP/REMNT LOW
120H 30/1200Z...DISSIPATED

$$
FORECASTER JACOBSON