CPAC: ANA - Post-Tropical

[tolakram]

Ana from the FTP site. ftp://goes.gsfc.nasa.gov/pub/goeswest/overview2/vis/

10/25 00:00Z, probably near peak.


10/25 03:00Z

[cycloneye]

HURRICANE ANA DISCUSSION NUMBER 48
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP022014
500 AM HST SAT OCT 25 2014

THE EYE OF HURRICANE ANA IS STILL EVIDENT IN INFRARED SATELLITE
IMAGERY EARLY THIS MORNING. HOWEVER...THE APPEARANCE OF THE EYE HAS
BEEN DEGRADED COMPARED WITH 6 HOURS AGO WHEN IT WAS A DISTINCT OPEN
CIRCLE SURROUNDED BY A WELL DEFINED EYEWALL STRUCTURE. THERE HAVE
BEEN PERIODS OF PARTIAL CLOUD FILLING OF THE EYE...BUT AS OF NOW ANA
CONTINUES TO MAINTAIN UNDENIABLE TROPICAL CYCLONE CHARACTERISTICS.
THE MOST RECENT SUBJECTIVE DVORAK ESTIMATES OF CURRENT INTENSITY
FROM PHFO AND SAB WERE 4.0/65 KT...WHILE JTWC ESTIMATED 4.5/77 KT.
THE LATEST UW-CIMSS OBJECTIVE INTENSITY ESTIMATES ARE 76 TO 79 KT.
THE MOST RECENT ENVIRONMENTAL VERTICAL WIND SHEAR ESTIMATES FOR ANA
FROM UW-CIMSS AND SHIPS ARE 4 AND 12 KT...RESPECTIVELY...FROM THE
NORTHWEST. BASED ON ALL AVAILABLE EVIDENCE...ANA WILL BE MAINTAINED
AS A MINIMAL HURRICANE WITH AN INITIAL INTENSITY OF 65 KT FOR THIS
ADVISORY.

ANA CONTINUES TO MOVE RAPIDLY NORTHEASTWARD...045/25 KT THIS
MORNING. THIS FAST FORWARD MOTION IS DUE TO THE DEEP STEERING FLOW
BETWEEN A MIDDLE-LEVEL ANTICYCLONE TO THE SOUTH SOUTHEAST...AND A
MIDDLE- TO UPPER-LEVEL TROUGH DIGGING DOWN TO THE NORTHWEST OF ANA.
THE LATEST MODEL GUIDANCE REMAINS TIGHTLY CLUSTERED THROUGH SUNDAY.
THEREFORE...THE MODEL CONSENSUS...OR TVCN...CONTINUES TO BE THE
PREFERRED TRACK GUIDANCE FOR THE 12-36 HOUR TIME PERIOD. AS A
RESULT...THE LATEST TRACK FORECAST THROUGH 36 HOURS HAS ONLY SUBTLE
CHANGES FROM THE PREVIOUS ADVISORY. NOTE THAT THE 36 TO 72 HOUR
FORECAST POSITIONS WERE SUPPLIED BY THE NOAA OCEAN PREDICTION
CENTER...OR OPC. THE OPC FORECASTS ARE BASED ON A BLEND OF THE
GFS/ECMWF MODELS DURING THE 36-48 HOUR TIME PERIOD...AND A BLEND OF
THE ECMWF/UKMET MODELS FOR DAYS 2-3.

IN REGARDS TO THE FORECAST INTENSITY...THE VERTICAL WIND SHEAR IS
EXPECTED TO BE RELATIVELY LOW TODAY. HOWEVER...ANA IS MOVING OVER
INCREASINGLY COOLER SEA SURFACE TEMPERATURES ALONG ITS FORECAST
TRACK. THESE DETRIMENTAL CONDITIONS SHOULD BEGIN TO TAKE A TOLL ON
THE MAINTENANCE OF THE DEEP CONVECTION NEAR THE CORE OF THE
HURRICANE LATER TODAY AND TONIGHT. THE CONSENSUS INTENSITY
GUIDANCE...OR ICON...CONTINUES TO SHOW A WEAKENING TREND...
ESPECIALLY AS FORECAST VERTICAL WIND SHEAR RAMPS UP IN THE NEXT 18
TO 24 HOURS. WE ARE FORECASTING ANA TO WEAKEN TO A STRONG TROPICAL
STORM LATER TODAY...WITH SOME ADDITIONAL WEAKENING EXPECTED TONIGHT.
BASED ON THE LATEST INPUT FROM OPC...ANA IS FORECAST TO TRANSITION
TO A STRONG EXTRATROPICAL LOW...LIKELY WITH STORM FORCE WINDS...
WITHIN 36 HOURS. THEREFORE...THE INTENSITY FORECAST AND WIND RADII
STARTING ON SUNDAY ARE BASED ON THE LATEST GUIDANCE FROM OPC. BY DAY
4...THE OPC FORECAST INDICATES ANA WILL LIKELY BE ABSORBED BY
ANOTHER EXTRATROPICAL LOW NEAR THE WEST COAST OF NORTH AMERICA.


FORECAST POSITIONS AND MAX WINDS

INIT 25/1500Z 34.3N 163.4W 65 KT 75 MPH
12H 26/0000Z 37.1N 159.2W 60 KT 70 MPH
24H 26/1200Z 41.4N 152.1W 55 KT 65 MPH
36H 27/0000Z 46.0N 144.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
48H 27/1200Z 48.2N 139.4W 45 KT 50 MPH...POST-TROP/EXTRATROP
72H 28/1200Z 48.9N 136.5W 45 KT 50 MPH...POST-TROP/EXTRATROP
96H 29/1200Z...ABSORBED

$$
FORECASTER HOUSTON

[Yellow Evan]

edit: Hurricane Two from 1957 attained hurricane status at 30.6N 152.0W
The unnamed 1975 Hurricane attained hurricane status at 40.0N, 156.0W

Meh, 1957 was pre-reliable record era.

Well, of course it is. It's in the BT database as such and that's what we have to go on. One other thing to consider is that 1957 fits the pattern in that it was a moderate warm ENSO phase, which would lend itself to enhanced CPAC TC activity, and the potential for higher latitude intensification.

1957-8 was a fairly strong El Nino and came after a long stretch of no Ninos.

Here was the SST plot:

[cycloneye]

HURRICANE ANA DISCUSSION NUMBER 49
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP022014
1100 AM HST SAT OCT 25 2014

THE EYE OF ANA HAS BEGUN TO FILL IN THE PAST COUPLE OF HOURS AS ITS
SATELLITE APPEARANCE IS DEGRADING. CONVECTIVE CLOUD TOPS ARE WARMING
IN THE WESTERN QUADRANT WHILE PERSISTENT DEEP CONVECTION REMAINS
ALONG THE EASTERN SEMICIRCLE OF THE EYE WALL. ALL THREE FIX AGENCIES
DETERMINED CURRENT INTENSITY VALUES OF 4.0/65 KT...AND CIMSS SATCON
FROM 1542Z CAME IN AT 62 KT. AS A RESULT...ANA WILL REMAIN A
HURRICANE WITH AN INTENSITY OF 65 KT.

ANA IS ACCELERATING TOWARD THE NORTHEAST WITH AN INITIAL MOTION OF
045/33 KT. THIS TREND WILL CONTINUE INTO SUNDAY AS ANA REMAINS
EMBEDDED WITHIN A DEEP SOUTHWEST FLOW ASSOCIATED WITH A MID-LATITUDE
TROUGH SWEEPING THROUGH FROM THE WEST. THE TRANSITION PROCESS INTO A
STRONG EXTRATROPICAL LOW WILL OCCUR TONIGHT AND EARLY SUNDAY AS THE
TWO FEATURES INCREASINGLY INTERACT...WITH THE FORWARD MOTION OF
EXTRATROPICAL ANA EXPECTED TO SLOW CONSIDERABLY ON SUNDAY NIGHT. THE
GUIDANCE IS TIGHTLY CLUSTERED THROUGH 24 HOURS WITH SOME INCREASE IN
SPREAD OCCURRING AFTER ANA BECOMES EXTRATROPICAL LATER SUNDAY. AT
36 HOURS AND BEYOND...FORECAST POSITIONS ARE BEING SUPPLIED BY THE
NOAA OCEAN PREDICTION CENTER AND ARE HEAVILY WEIGHTED TOWARD THE
ECMWF AT THAT TIME. BY 24 HOURS THE EXTRATROPICAL LOW OF ANA IS
EXPECTED TO BE NEARING THE BRITISH COLUMBIA COAST OF CANADA.

SOME WEAKENING IS EXPECTED THROUGH AT LEAST THE NEXT 24 HOURS...WITH
ANA FORECAST TO BE A STRONG EXTRATROPICAL LOW BY SUNDAY NIGHT. ANA
IS ALREADY BEGINNING TO INTERACT WITH THE MID-LATITUDE TROUGH...BUT
VERTICAL WIND SHEAR REMAINS RATHER LOW...AROUND 10 KT ACCORDING TO A
RECENT CIMSS ANALYSIS...DUE TO THE DEEP SOUTHWESTERLY FLOW STEERING
ANA. AS A RESULT...THE SHORT TERM WEAKENING OF ANA WILL BE DRIVEN BY
INCREASINGLY COOLER OCEAN TEMPERATURES...ALREADY DOWN TO ABOUT 20C
AND DROPPING TO 15C LATE TONIGHT ALONG THE FORECAST TRACK. THE
FORECAST CURRENTLY CALLS FOR EXTRATROPICAL TRANSITION TO OCCUR BY 36
HOURS...BUT THE COMBINATION OF RAPIDLY DECREASING OCEAN TEMPERATURES
AND INCREASING VERTICAL WIND SHEAR COULD LEAD TO EXTRATROPICAL
TRANSITION AS EARLY AS LATE TONIGHT. THE INTENSITY FORECAST FOLLOWS
CLOSELY TO ICON THROUGH 24 HOURS AND IS THEREAFTER BASED ON INPUT
FROM THE OCEAN PREDICTION CENTER...WHICH MAINTAINS THE
EXTRATROPICAL LOW AT OR NEAR STORM FORCE.


FORECAST POSITIONS AND MAX WINDS

INIT 25/2100Z 36.3N 160.9W 65 KT 75 MPH
12H 26/0600Z 39.3N 156.0W 55 KT 65 MPH
24H 26/1800Z 44.0N 147.4W 50 KT 60 MPH
36H 27/0600Z 48.0N 143.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
48H 27/1800Z 49.0N 142.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
72H 28/1800Z 52.4N 133.8W 45 KT 50 MPH...POST-TROP/EXTRATROP
96H 29/1800Z...ABSORBED

$$
FORECASTER WROE

[cycloneye]

TROPICAL STORM ANA DISCUSSION NUMBER 50
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP022014
500 PM HST SAT OCT 25 2014

THE SATELLITE PRESENTATION OF ANA HAS BEEN STEADILY DEGRADING
TODAY. THERE IS NO EYE STRUCTURE REMAINING...AND DEEP CONVECTION
HAS NEARLY CEASED IN THE WESTERN SEMICIRCLE. VERTICAL WIND SHEAR IS
INCREASING...UP TO ABOUT 25 KT ACCORDING TO A RECENT CIMSS
ANALYSIS...DUE TO INTERACTION WITH A DEEP MID-LATITUDE TROUGH...AND
SEA SURFACE TEMPERATURES ARE DOWN TO ABOUT 20C. HFO AND JTWC BOTH
CAME IN WITH CURRENT INTENSITY VALUES OF 4.0/65 KT WHILE SAB HAD
3.5/55 KT. FINAL T NUMBERS FROM ALL AGENCIES WERE LOWER...AND THE
INTENSITY FOR THIS ADVISORY IS LOWERED TO 60 KT.

ANA CONTINUES TO MOVE RAPIDLY TO THE NORTHEAST WITH AN INITIAL
MOTION OF 050/35 KT. ANA IS TRAVELING WITHIN DEEP SOUTHWESTERLY
FLOW AHEAD OF A COLD FRONT AND AN ASSOCIATED A MID-LATITUDE LOW
PRESSURE SYSTEM TO THE WEST AND NORTH. THIS MOTION WILL CONTINUE
THROUGH THROUGH EARLY SUNDAY AS ANA INTERACTS WITH THE MID-LATITUDE
LOW AND UNDERGOES EXTRATROPICAL TRANSITION. THE FORWARD MOTION OF
EXTRATROPICAL ANA WILL SLOW CONSIDERABLY LATE SUNDAY AS IT COMES IN
CLOSE PROXIMITY TO THE MID-LATITUDE LOW. THE GUIDANCE REMAINS
TIGHTLY CLUSTERED IN THE SHORT TERM WITH SOME INCREASE IN SPREAD
OCCURRING AFTER ANA BECOMES EXTRATROPICAL. AT 24 HOURS AND BEYOND...
FORECAST POSITIONS ARE BEING SUPPLIED BY THE NOAA OCEAN PREDICTION
CENTER AND ARE HEAVILY WEIGHTED TOWARD THE UKMET AND ECMWF AT THAT
TIME. BY TUESDAY THE EXTRATROPICAL LOW OF ANA IS EXPECTED TO BE
NEARING THE BRITISH COLUMBIA COAST OF CANADA.

CONTINUED WEAKENING IS EXPECTED AS ANA UNDERGOES EXTRATROPICAL
TRANSITION TONIGHT OR EARLY SUNDAY. VERTICAL WIND SHEAR WILL RISE
STEADILY AS ANA INCREASINGLY INTERACTS WITH THE MID-LATITUDE LOW...
AND SEA SURFACE TEMPERATURES WILL BE DECREASING TO ABOUT 15C ALONG
THE TRACK TONIGHT...DEPRIVING ANA OF ENERGY. THE CURRENT FORECAST
CALLS FOR ANA TO STILL BE A TROPICAL SYSTEM AT THE 12 HOUR FORECAST
POINT TONIGHT...BUT THE GFS AND ECMWF DEPICT THE WARM CORE ALOFT
DEGRADING RAPIDLY AROUND THAT TIME...HINTING AT A HASTENING TO THE
TRANSITION TO AN EXTRATROPICAL LOW AS EARLY AS TONIGHT. THE
INTENSITY FORECAST CLOSELY FOLLOWS THE HWRF AND THE TREND OF THE
CONSENSUS THROUGH 24 HOURS AND IS THEREAFTER BASED ON INPUT FROM
THE OCEAN PREDICTION CENTER. IT IS IMPORTANT TO NOTE THAT EVEN
THOUGH THE SYSTEM WILL BE WEAKENING...THE WIND FIELD WILL BE
EXPANDING AS EXTRATROPICAL TRANSITION OCCURS.


FORECAST POSITIONS AND MAX WINDS

INIT 26/0300Z 38.1N 157.4W 60 KT 70 MPH
12H 26/1200Z 41.4N 151.8W 55 KT 65 MPH
24H 27/0000Z 46.1N 144.1W 50 KT 60 MPH
36H 27/1200Z 49.2N 141.6W 45 KT 50 MPH...POST-TROP/EXTRATROP
48H 28/0000Z 49.3N 141.2W 45 KT 50 MPH...POST-TROP/EXTRATROP
72H 29/0000Z 53.3N 131.7W 35 KT 40 MPH...POST-TROP/EXTRATROP
96H 30/0000Z...ABSORBED

$$
FORECASTER WROE

[cycloneye]

Yellow Evan,Is Ana the longest TC that lasted the most days at CPAC?

POST-TROPICAL CYCLONE ANA DISCUSSION NUMBER 52
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP022014
500 AM HST SUN OCT 26 2014

ANA HAS COMPLETED THE TRANSFORMATION INTO AN EXTRATROPICAL CYCLONE.
DUE TO STRONG SOUTHWESTERLY SHEAR...THE DIMINISHING COLD CLOUD TOPS
ARE LOCATED NORTHEAST AND EAST OF THE NEARLY EXPOSED LOW LEVEL
CENTER...WHILE COLD AIR STRATOCUMULUS CLOUDS ARE SEEN WRAPPING IN
TOWARD THE CENTER FROM THE NORTH AND WEST. ADDITIONALLY...THE MAIN
CLOUD SHIELD BEGAN TO RESEMBLE A BAROCLINIC LEAF EARLIER IN THE
NIGHT...INDICATING THE TRANSITION WAS WELL UNDERWAY AT THAT TIME.
THE INITIAL INTENSITY FOR THIS ADVISORY IS SET AT 50 KT BASED
ON A BLEND OF THE AVAILABLE SUBJECTIVE AND OBJECTIVE SATELLITE
ANALYSES.

ANA WILL CONTINUE TO TRACK RAPIDLY NORTHEAST TODAY...WITH AN
INITIAL MOTION ESTIMATE OF 060/40 KT. THE FORWARD MOTION OF THE
CYCLONE IS EXPECTED TO SLOW CONSIDERABLY TONIGHT AND MONDAY AS IT
INTERACTS...AND EVENTUALLY MERGES...WITH AN EXTRATROPICAL GALE LOW
CURRENTLY TO ITS NORTH. THE RESULTANT LOW IS FORECAST TO GRADUALLY
WEAKEN BEFORE MOVING ASHORE IN BRITISH COLUMBIA ON TUESDAY...AND
DISSIPATING INLAND. THE OFFICIAL FORECAST CLOSELY FOLLOWS A
CONSENSUS OF THE GLOBAL MODELS...AND WAS MADE IN COLLABORATION WITH
THE NOAA OCEAN PREDICTION CENTER.

THIS IS THE LAST CPHC ADVISORY ON THIS SYSTEM. ADDITIONAL
INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS
ISSUED BY THE NATIONAL WEATHER SERVICE UNDER AWIPS HEADER NFDHSFEP1
AND WMO HEADER FZPN01 KWBC.


FORECAST POSITIONS AND MAX WINDS

INIT 26/1500Z 42.2N 147.9W 50 KT 60 MPH...POST-TROP/EXTRATROP
12H 27/0000Z 45.4N 144.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
24H 27/1200Z 48.8N 140.8W 45 KT 50 MPH...POST-TROP/EXTRATROP
36H 28/0000Z 48.1N 139.4W 45 KT 50 MPH...POST-TROP/EXTRATROP
48H 28/1200Z 48.8N 132.6W 40 KT 45 MPH...POST-TROP/EXTRATROP
72H 29/1200Z...DISSIPATED

$$

FORECASTER BIRCHARD

[Yellow Evan]

Yellow Evan,Is Ana the longest TC that lasted the most days at CPAC?

I don't like considering the EPAc and CPAC separate, but yes. It smashed the old record of Uleki 88, which lasted 11.5 days.

[galaxy401]

She seemed to last forever. Nice knowing you Ana.

[hurricanes1234]

Very long lasting system. Also made it to an impressive northerly latitude. Bye Ana!