Tropical Cyclone ALFRED (18P)

WTPS31 PGTW 231500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 18P (ALFRED) WARNING NR 005//
RMKS/
1. TROPICAL CYCLONE 18P (ALFRED) WARNING NR 005    
   02 ACTIVE TROPICAL CYCLONES IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   231200Z --- NEAR 14.6S 152.8E
     MOVEMENT PAST SIX HOURS - 070 DEGREES AT 03 KTS
     POSITION ACCURATE TO WITHIN 025 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF 
     SATELLITE AND SYNOPTIC DATA
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            025 NM SOUTHWEST QUADRANT
                            025 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT
                            090 NM SOUTHEAST QUADRANT
                            065 NM SOUTHWEST QUADRANT
                            115 NM NORTHWEST QUADRANT
   REPEAT POSIT: 14.6S 152.8E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   240000Z --- 14.7S 153.8E
   MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            080 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 105 DEG/ 04 KTS
    ---
   24 HRS, VALID AT:
   241200Z --- 14.9S 154.5E
   MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT
                            000 NM SOUTHEAST QUADRANT
                            000 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT
                            080 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            090 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 130 DEG/ 03 KTS
    ---
   36 HRS, VALID AT:
   250000Z --- 15.3S 155.0E
   MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT
                            020 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            030 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT
                            110 NM SOUTHEAST QUADRANT
                            090 NM SOUTHWEST QUADRANT
                            100 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 150 DEG/ 03 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   251200Z --- 15.8S 155.3E
   MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            010 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT
                            140 NM SOUTHEAST QUADRANT
                            120 NM SOUTHWEST QUADRANT
                            110 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 160 DEG/ 04 KTS
    ---
   72 HRS, VALID AT:
   261200Z --- 17.3S 155.9E
   MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT
                            190 NM SOUTHEAST QUADRANT
                            160 NM SOUTHWEST QUADRANT
                            110 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 170 DEG/ 05 KTS
    ---
   LONG RANGE OUTLOOK:
    ---
   96 HRS, VALID AT:
   271200Z --- 19.3S 156.3E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT
                            020 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 100 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT
                            180 NM SOUTHEAST QUADRANT
                            160 NM SOUTHWEST QUADRANT
                            120 NM NORTHWEST QUADRANT
   VECTOR TO 120 HR POSIT: 170 DEG/ 04 KTS
    ---
   120 HRS, VALID AT:
   281200Z --- 21.0S 156.6E
   MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 000 NM NORTHEAST QUADRANT
                            120 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT
                            180 NM SOUTHEAST QUADRANT
                            140 NM SOUTHWEST QUADRANT
                            090 NM NORTHWEST QUADRANT
    ---
REMARKS:
231500Z POSITION NEAR 14.6S 153.1E.
23FEB25. TROPICAL CYCLONE 18P (ALFRED), LOCATED APPROXIMATELY 427
NM EAST-NORTHEAST OF CAIRNS, AUSTRALIA, HAS TRACKED EAST-
NORTHEASTWARD AT 03 KNOTS OVER THE PAST SIX HOURS.
MINIMUM CENTRAL PRESSURE AT 231200Z IS 994 MB. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 231200Z IS 21 FEET. NEXT WARNINGS AT
240300Z AND 241500Z.
REFER TO TROPICAL CYCLONE 19P (RAE) WARNINGS (WTPS32 PGTW)
FOR TWELVE-HOURLY UPDATES.
//
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WDPS31 PGTW 231500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 18P (ALFRED) WARNING NR 
005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.6S 152.8E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 427 NM EAST-NORTHEAST OF CAIRNS, AUSTRALIA
   MOVEMENT PAST 6 HOURS: EAST-NORTHEASTWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 21 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS DEEP
CONVECTIVE BANDS WRAPPING INTO AN OBSCURED LOW-LEVEL CIRCULATION
CENTER. CIRRUS FILAMENTS LEAD INTO A STRONG POLEWARD AND EASTWARD
OUTFLOW CHANNEL ENHANCED BY THE JET TO THE SOUTH. THE INITIAL
POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE
AFOREMENTIONED ANIMATED EIR. THE INITIAL INTENSITY OF 55 KTS IS
ASSESSED WITH LOW CONFIDENCE BASED THE AGENCY AND OBJECTIVE FIXES
BELOW, BUT IS LESS CERTAIN DUE TO A 230800Z RCM-1 SYNTHETIC
APERTURE RADAR WIND SPEED PRODUCT INDICATING MAXIMUM WIND SPEEDS UP
TO 83KTS, WHICH IS CONSIDERABLY HIGH GIVEN THE STRUCTURE OF THE
SYSTEM.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: A NEAR EQUATORIAL RIDGE TO THE
NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   ABRF: T3.5 - 55 KTS
   CIMSS SATCON: 57 KTS AT 230846Z
   CIMSS ADT: 57 KTS AT 231130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: LOW
   INITIAL WIND RADII: LOW

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THE RATE OF INTENSIFICATION IS SLOWER
THAN REFLECTED IN THE PREVIOUS WARNING DUE TO HIGH VERTICAL WIND
SHEAR THAT IS INTRODUCED AFTER TAU 48 AND CONTINUES TO ERODE THE
CIRCULATION FOR THE REMAINDER OF THE FORECAST.

FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 18P WILL SLOWLY CURVE
FROM AN EASTWARD TRACK DURING THE FIRST 24 HOURS OF THE FORECAST
PERIOD TO A SOUTH-SOUTHEASTWARD TRACK BY THE END OF THE FORECAST
PERIOD UNDER THE STEERING INFLUENCE OF A NEAR EQUATORIAL RIDGE TO
THE NORTHEAST. THE SYSTEM IS EXPECTED TO INTENSIFY TO A PEAK OF
80KTS WITHIN THE FIRST 48 HOURS DUE TO LOW VERTICAL WIND SHEAR AND
CONTINUED STRONG POLEWARD OUTFLOW. AFTER TAU 48, VERTICAL WIND
SHEAR WILL INCREASE UNFAVORABLY TO 20-25KTS RESULTING IN WEAKENING
TO 60 KTS BY THE END OF THE FORECAST. DESPITE THE UNFAVORABLE
SHEAR, SEA SURFACE TEMPERATURES AND OUTFLOW WILL REMAIN SUPPORTIVE.


MODEL DISCUSSION: THE JTWC MULTI-MODEL CONSENSUS HAS A LARGE SPREAD
OF MODEL SOLUTIONS LEADING TO A CROSS-TRACK SPREAD OF 373NM BY THE
END OF THE FORECAST. THE SPREAD OF SOLUTIONS CAN BE ATTRIBUTED TO
DIFFERENT VARIATIONS OF HOW SHARPLY THE NEAR EQUATORIAL RIDGE
DRIVES THE SYSTEM AND WHETHER OR NOT THE RIDGE BREAKS DOWN. THE
INTENSITY GUIDANCE IS LARGELY SPREAD BETWEEN THE RAPID
INTENSIFICATION AIDS AND HAFS-A, HWRF, COAMPS-TC, AND GFS WHICH
DEPICT MINIMAL INTENSIFICATION IN THE NEAR-TERM FORECAST. WITHOUT
BITING OFF COMPLETELY ON THE SUDDEN DROP IN INTENSIFICATION
GUIDANCE, THE FORECAST INTENSITY WAS LOWERED BASED ON THE NEWLY
INDICATED SHEAR AFTER TAU 48.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: LOW
   TRACK 72-120 HR: LOW
   INTENSITY 0 - 72 HR: LOW
   INTENSITY 72-120 HR: LOW//
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