SPO: ATU (11F/17P) Tropical Cyclone

[GCANE]

Looks like it is already building a much bigger outer eyewall.

[HURAKAN]

TROPICAL DISTURBANCE ADVISORY NUMBER A11 ISSUED FROM RSMC NADI
Feb 20/1358 UTC 2011 UTC.

SEVERE TROPICAL CYCLONE ATU CENTRE 940HPA CAT 4 WAS LOCATED NEAR
17.0S 169.5E AT 201200 UTC. POSITION GOOD BASED ON MTSAT EIR IMAGERY
AND PERIPHERAL SURFACE OBSERVATIONS. CYCLONE MOVING SOUTHEAST AT
ABOUT 3 KNOTS. MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE
ESTIMATED AT ABOUT 90 KNOTS AND INCREASING TO 100 KNOTS BY 210000
UTC.
EXPECT WINDS OVER 63 KNOTS WITHIN 30 NAUTICAL MILES OF CENTRE OVER 47
KNOTS WITHIN 40 NAUTICAL MILES OF CENTRE AND OVER 33 KNOTS WITHIN 200
NAUTICAL MILES IN NE QUADRANT AND WITHIN 150 NAUTICAL MILES IN SE
QUADRANT AND WITHIN 80 NAUTICAL MILES IN SW QUADRANT AND WITHIN 60
NAUTICAL MILES IN NW QUADRANT.

TC ATU INTENSIFIED RAPIDLY PAST 12 HOURS. ORGANISATION HAS IMPROVED
SIGNIFICANTLY IN THE LAST 24 HOURS. EYE WELL DEFINED. ATU CONTINUES
TO INTENSIFY WITH EYE WARMING AND CONVECTIVE TOPS COOLING. OUTFLOW
GOOD. SST AROUND 29 DEGREES CELCIUS. SYSTEM LIES UNDER AN UPPER
DIFFLUENT REGION IN A WEAK SHEARED ENVIRONMENT. CIMSS INDICATES
DECREASING SHEAR ALONG FORECAST PATH. SYSTEM IS BEING STEERED
SOUTHEAST BY A WEAK NORHTWESTERLY DEEP LAYER MEAN WIND. DVORAK
ASSESSMENT BASED ON DG EYE W SURROUND YIELDING DT = 6.5, MET =5.0 PT
= 5.5, FT BASED ON PT, THUS T5.5/5.5/D2.0/24HRS.
GLOBAL MODELS ARE INTENSIFYING THE SYSTEM AND GRADUALLY MOVING IT
SOUTH-SOUTHEASTWARDS.

FORECASTS :
AT 12 HRS VALID AT 210000 UTC 17.7S 169.8E MOV SSE AT 04 KT WITH 100
KT CLOSE TO CENTRE
AT 24 HRS VALID AT 211200 UTC 19.0S 170.2E MOV SSE AT 06 KT WITH 105
KT CLOSE TO CENTRE

OUTLOOK :
AT 36 HRS VALID AT 220000 UTC 20.6S 170.6E MOV SSE AT 08 KT WITH 105
KT CLOSE TO CENTRE
AT 48 HRS VALID AT 221200 UTC 22.7S 171.6E MOV SSE AT 10 KT WITH 105
KT CLOSE TO CENTRE

THE NEXT TROPICAL DISTURBANCE ADVISORY ON CYCLONE ATU WILL BE ISSUED
AROUND 202000 UTC.

[HURAKAN]

Latest microwave ... looks like an EWRC is underway

[HURAKAN]

Latest microwave and infrared ... NRL : 110 knots

[KWT]

Interestingly I think its probably not 110kts anymore, probably closer IMO to 100kts now, though I have few doubts 110kts was probably close to its max 6-12hrs ago.

[cycloneye]

The 18:00z update at NRL has it at 115kts and 937 mbs.

[Bobo2000]

Near 120kts 936 mbs

[cycloneye]

JTWC 2100z Warning=115 kts

WTPS31 PGTW 202100
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 17P (ATU) WARNING NR 005//
RMKS/
1. TROPICAL CYCLONE 17P (ATU) WARNING NR 005
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
201800Z --- NEAR 17.4S 169.7E
MOVEMENT PAST SIX HOURS - 150 DEGREES AT 04 KTS
POSITION ACCURATE TO WITHIN 040 NM
POSITION BASED ON EYE FIXED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 085 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
075 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT
165 NM SOUTHEAST QUADRANT
140 NM SOUTHWEST QUADRANT
150 NM NORTHWEST QUADRANT
REPEAT POSIT: 17.4S 169.7E
---
FORECASTS:
12 HRS, VALID AT:
210600Z --- 18.4S 170.1E
MAX SUSTAINED WINDS - 120 KT, GUSTS 145 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT
090 NM SOUTHEAST QUADRANT
080 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT
175 NM SOUTHEAST QUADRANT
155 NM SOUTHWEST QUADRANT
160 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 160 DEG/ 08 KTS
---
24 HRS, VALID AT:
211800Z --- 19.9S 170.7E
MAX SUSTAINED WINDS - 120 KT, GUSTS 145 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT
090 NM SOUTHEAST QUADRANT
080 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT
175 NM SOUTHEAST QUADRANT
155 NM SOUTHWEST QUADRANT
160 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 160 DEG/ 12 KTS
---
36 HRS, VALID AT:
220600Z --- 22.2S 171.5E
MAX SUSTAINED WINDS - 110 KT, GUSTS 135 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 085 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
075 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 165 NM NORTHEAST QUADRANT
165 NM SOUTHEAST QUADRANT
140 NM SOUTHWEST QUADRANT
150 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 155 DEG/ 17 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
221800Z --- 25.3S 173.1E
MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 155 NM NORTHEAST QUADRANT
160 NM SOUTHEAST QUADRANT
135 NM SOUTHWEST QUADRANT
140 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 140 DEG/ 21 KTS
---
72 HRS, VALID AT:
231800Z --- 31.4S 179.6E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 075 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT
170 NM SOUTHEAST QUADRANT
135 NM SOUTHWEST QUADRANT
130 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 145 DEG/ 26 KTS
---
LONG RANGE OUTLOOK:
NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 250 NM
ON DAY 4 AND 350 NM ON DAY 5... AND FOR INTENSITY
NEAR 20 KT EACH DAY.
---
96 HRS, VALID AT:
241800Z --- 39.9S 173.0W
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
202100Z POSITION NEAR 17.7S 169.8E.
TROPICAL CYCLONE (TC) 17P (ATU), LOCATED APPROXIMATELY 80 NM EAST-
NORTHEAST OF PORT VILA, VANUATU, HAS TRACKED SOUTH-SOUTHEASTWARD AT
04 KNOTS OVER THE PAST SIX HOURS. RECENT DVORAK T-NUMBER ESTIMATES
OF 6.0 FROM PGTW, PHFO, AND KNES INDICATE THAT THE MAXIMUM SUSTAINED
SURFACE WIND ASSOCIATED WITH THE CYCLONE HAS INCREASED TO AN
ESTIMATED 115 KNOTS. RECENT ANIMATED INFRARED SATELLITE IMAGERY
INDICATES FORMATION OF A 22 NM BANDING EYE FEATURE, ALSO EVIDENT IN
RECENT MICROWAVE SATELLITE IMAGERY. TC 17P IS TRACKING ALONG THE
WESTERN PERIPHERY OF A SUBTROPICAL RIDGE TO THE EAST. THIS RIDGE
WILL CONTINUE TO BUILD OVER THE NEXT FEW DAYS TO THE NORTHWEST OF
THE CYCLONE, STEERING THE SYSTEM GENERALLY SOUTH-SOUTHEASTWARD
THROUGH THE FORECAST PERIOD. AS A MID-LATITUDE TROUGH APPROACHES
FROM THE SOUTHWEST, TC 17P WILL ACCELERATE TOWARD THE BAROCLINIC
ZONE, PARTICULARLY AFTER TAU 36. BY TAU 72, INCREASING VERTICAL WIND
SHEAR AHEAD OF THE APPROACHING TROUGH, ENTRAINMENT OF DRIER AIR, AND
PASSAGE OVER A COOLER SEA SURFACE WILL INDUCE THE FIRST PHASE OF
EXTRATROPICAL TRANSITION. BY TAU 96 THE CYCLONE IS EXPECTED TO BE
FULLY EXTRATROPICAL, THROUGH STILL QUITE INTENSE DUE TO FAVORABLE
INTERACTION WITH THE MID-LATITUDE UPPER-LEVEL FLOW PATTERN. THE
NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH THE CURRENT FORECAST,
WHICH LIES SLIGHTLY EAST OF AND FASTER THAN THE MODEL CONSENSUS.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 201800Z IS 31 FEET. NEXT WARNINGS
AT 210900Z AND 212100Z.//
NNNN

[HURAKAN]

Latest

[HURAKAN]

Latest microwave

[cycloneye]

The latest.

[HURAKAN]

TROPICAL DISTURBANCE ADVISORY NUMBER A12 ISSUED FROM RSMC NADI
Feb 20/2032 UTC 2011 UTC.

SEVERE TROPICAL CYCLONE ATU CENTRE 940HPA CAT 4 WAS LOCATED NEAR
17.4S 169.7E AT 201800 UTC. POSITION GOOD BASED ON MTSAT EIR IMAGERY
AND PERIPHERAL SURFACE OBSERVATIONS. CYCLONE SLOW MOVING. MAXIMUM
10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT ABOUT 90 KNOTS
AND INCREASING TO 100 KNOTS WITHIN THE NEXT 6 TO 18 HOURS.
EXPECT WINDS OVER 63 KNOTS WITHIN 30 NAUTICAL MILES OF CENTRE.
EXPECT WINDS OVER 47 KNOTS WITHIN 40 NAUTICAL MILES OF CENTRE.
EXPECT WINDS OVER 33 KNOTS WITHIN 200 NAUTICAL MILES OF CENTRE IN NE
QUADRANT
AND WITHIN 150 NAUTICAL MILES OF CENTRE IN SE QUADRANT
AND WITHIN 100 NAUTICAL MILES OF CENTRE IN SW QUADRANT
AND WITHIN 80 NAUTICAL MILES OF CENTRE IN NW QUADRANT.

SYSTEM INTENSIFIED RAPIDLY PAST 12 HOURS. ORGANISATION HAS IMPROVED
SIGNIFICANTLY IN THE LAST 24 HOURS. EYE HAS BECOME CLOUD FILLED IN
PAST 3 HOURS. SYSTEM CONTINUES TO INTENSIFY WITH CONVECTIVE TOPS
COOLING. PRIMARY BANDS TO SOUTH AND WEST OF SYSTEM DISSIPATING DUE TO
DRY AIR ENTRAINMENT PAST 4 HOURS THOUGH THIS COULD ALSO BE PART
OF EYE WALL REPLACEMENT PROCESS. OUTFLOW GOOD TO SOUTH AND EAST AND
FAIR ESLEWHERE. SST AROUND 29C. SYSTEM LIES ALONG IN A WEAK SHEAR
ENVIRONMENT. CIMSS INDICATES DECREASING SHEAR ALONG FORECAST PATH.
SYSTEM IS BEING STEERED SOUTHEAST BY A WEAK NORHTWESTERLY DEEP LAYER
MEAN WIND. DVORAK ASSESSMENT BASED ON B EYE W SURROUND YIELDING
DT6.0, MET 5.5 PT 5.5, FT BASED ON PT, THUS T5.5/5.5/D2.0/24HRS.
GLOBAL MODELS ARE INTENSIFYING THE SYSTEM AND ARE MOVING IT
SOUTHEASTWARDS.

FORECASTS :
AT 12 HRS VALID AT 210600 UTC 18.3S 170.1E MOV SSE AT 05 KT WITH 100
KT CLOSE TO CENTRE
AT 24 HRS VALID AT 211800 UTC 19.6S 170.6E MOV SSE AT 06 KT WITH 100
KT CLOSE TO CENTRE

OUTLOOK :
AT 36 HRS VALID AT 220600 UTC 21.4S 171.4E MOV SSE AT 07 KT WITH 100
KT CLOSE TO CENTRE
AT 48 HRS VALID AT 221800 UTC 23.7S 172.5E MOV SSE AT 09 KT WITH 95
KT CLOSE TO CENTRE

THE NEXT TROPICAL DISTURBANCE ADVISORY ON CYCLONE ATU WILL BE ISSUED
AROUND 210200 UTC.

[Crostorm]

[HURAKAN]

Latest microwave and infrared

[HURAKAN]

TROPICAL DISTURBANCE ADVISORY NUMBER A14 ISSUED FROM RSMC NADI
Feb 21/0811 UTC 2011 UTC.

SEVERE TROPICAL CYCLONE ATU CENTRE 949HPA CAT 4 WAS LOCATED NEAR
18.3S 170.2E AT 210600 UTC. POSITION GOOD BASED ON MTSAT EIR/VIS
IMAGERY AND PERIPHERAL SURFACE OBSERVATIONS. CYCLONE MOVING SOUTHEAST
AT 05 KNOTS. MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE
ESTIMATED AT ABOUT 90 KNOTS AND INCREASING TO 95 KNOTS WITHIN THE
NEXT 24 HOURS.
EXPECT WINDS OVER 63 KNOTS WITHIN 30 NAUTICAL MILES OF CENTRE.
EXPECT WINDS OVER 47 KNOTS WITHIN 60 NAUTICAL MILES OF CENTRE IN
EASTERN SEMICIRCLE AND WITHIN 40 NAUTICAL MILES OF CENTRE ELSEWHERE.
EXPECT WINDS OVER 33 KNOTS WITHIN 200 NAUTICAL MILES OF CENTRE IN NE
QUADRANT
AND WITHIN 160 NAUTICAL MILES OF CENTRE IN SE QUADRANT
AND WITHIN 120 NAUTICAL MILES OF CENTRE IN SW QUADRANT
AND WITHIN 100 NAUTICAL MILES OF CENTRE IN NW QUADRANT.

STRUCTURE OF THE SYSTEM HAS SLIGHTLY WEAKEN IN LAST 6 HOURS BUT THE
OVERALL ORGANISATION REMAINS GOOD IN THE PAST 24 HOURS. EYE HAS
SLIGHTLY EXPOSED. SLIGHT WARMING OF CLOUD TOPS PAST 6 HOURS. PRIMARY
BANDS TO SOUTH OF SYSTEM DISSIPATED WHILE THE BAND TO THE NORTH HAS
CONSOLIDATED AND WRAPPED AROUND LLCC. OUTFLOW GOOD TO NORTH AND EAST
BUT RESTRICTED ESLEWHERE. SST AROUND 29C. SYSTEM LIES ALONG IN A WEAK
SHEAR ENVIRONMENT. CIMSS INDICATES DECREASING SHEAR ALONG FORECAST
PATH. SYSTEM IS BEING STEERED SOUTHEAST BY A WEAK NORHTWESTERLY DEEP
LAYER MEAN WIND. DVORAK ASSESSMENT BASED ON EYE PATTERN WITH DG EYE
AND LG SURROUND YIELDING DT = 5.0, MET 5.0 PT 5.0, FT BASED ON DT,
THUS T5.0/5.5/D0.5/24HRS.
GLOBAL MODELS MOVING THE SYSTEM SOUTHEASTWARDS AND SLIGHT
INTENSIFICATION.

FORECASTS :
AT 12 HRS VALID AT 211800 UTC 19.8S 170.7E MOV SSE AT 08 KT WITH 95
KT CLOSE TO CENTRE
AT 24 HRS VALID AT 220000 UTC 21.8S 171.4E MOV SSE AT 10 KT WITH 95
KT CLOSE TO CENTRE

OUTLOOK :
AT 36 HRS VALID AT 221800 UTC 24.2S 172.5E MOV SSE AT 15 KT WITH 80
KT CLOSE TO CENTRE
AT 48 HRS VALID AT 230600 UTC 26.9S 174.5E MOV SSE AT 16 KT WITH 60
KT CLOSE TO CENTRE

THE NEXT TROPICAL DISTURBANCE ADVISORY ON CYCLONE ATU WILL BE ISSUED
AROUND 211400 UTC.

[HURAKAN]

Latest

[HURAKAN]

Latest infrared

[HURAKAN]

TROPICAL DISTURBANCE ADVISORY NUMBER A15 ISSUED FROM RSMC NADI
Feb 21/1357 UTC 2011 UTC.

SEVERE TROPICAL CYCLONE ATU CENTRE 940HPA CAT 4 WAS LOCATED NEAR
19.0S 170.5E AT 211200 UTC. POSITION GOOD BASED ON MTSAT IR IMAGERY
AND PERIPHERAL SURFACE OBSERVATIONS. CYCLONE MOVING SOUTH SOUTHEAST
AT 06 KNOTS. MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE
ESTIMATED AT ABOUT 90 KNOTS.
EXPECT WINDS OVER 63 KNOTS WITHIN 30 NAUTICAL MILES OF CENTRE.
EXPECT WINDS OVER 47 KNOTS WITHIN 80 NAUTICAL MILES OF CENTRE IN THE
NE QUADRANT
AND WITHIN 130 NAUTICAL MILES OF CENTRE IN SE QUADRANT
AND WITHIN 80 NAUTICAL MILES OF CENTRE IN SW QUADRANT
AND WITHIN 40 NAUTICAL MILES OF CENTRE IN NW QUADRANT.
EXPECT WINDS OVER 33 KNOTS WITHIN 200 NAUTICAL MILES OF CENTRE IN NE
QUADRANT
AND WITHIN 160 NAUTICAL MILES OF CENTRE IN SE QUADRANT
AND WITHIN 100 NAUTICAL MILES OF CENTRE IN WESTERN SEMICIRCLE..

OVERALL ORGANISATION REMAINS GOOD. EYE PARTIALLY CLOUD FILLED BUT
STILL DISCERNIBLE. EYE WARMING AND CLOUD TOPS COOLING PAST 3 HOURS.
PRIMARY BANDS WRAPPING AROUND LLCC. OUTFLOW GOOD TO NORTH AND EAST
BUT FAIR ESLEWHERE. SST AROUND 29C. SYSTEM LIES ALONG A WEAK SHEARED
ENVIRONMENT. CIMSS INDICATES INCREASING SHEAR THAN DECREASING SHEAR
ALONG FORECAST PATH. SYSTEM IS BEING STEERED SOUTHEAST BY A
NORHTWESTERLY DEEP LAYER MEAN WIND. DVORAK ASSESSMENT BASED ON EYE
PATTERN WITH OW EYE AND LG SURROUND YIELDING DT = 5.0, MET 5.5 PT
5.0, FT BASED ON DT, THUS T5.0/5.5/S0.0/24HRS.
GLOBAL MODELS MOVE THE SYSTEM SOUTH SOUTHEAST.

FORECASTS :
AT 12 HRS VALID AT 220000 UTC 20.9.8S 171.3E MOV SSE AT 12 KT WITH 90
KT CLOSE TO CENTRE
AT 24 HRS VALID AT 221200 UTC 23.6S 172.6E MOV SSE AT 15 KT WITH 90
KT CLOSE TO CENTRE

OUTLOOK :
AT 36 HRS VALID AT 230000 UTC 26.7S 174.7E MOV SSE AT 17 KT WITH 90
KT CLOSE TO CENTRE
AT 48 HRS VALID AT 231200 UTC 30.1S 177.8E MOV SE AT 20 KT WITH 85 KT
CLOSE TO CENTRE

THE NEXT TROPICAL DISTURBANCE ADVISORY ON CYCLONE ATU WILL BE ISSUED
AROUND 212000 UTC.

[HURAKAN]

Latest

[HURAKAN]

WTPS31 PGTW 212100
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 17P (ATU) WARNING NR 007//
RMKS/
1. TROPICAL CYCLONE 17P (ATU) WARNING NR 007
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
211800Z --- NEAR 19.9S 171.1E
MOVEMENT PAST SIX HOURS - 150 DEGREES AT 09 KTS
POSITION ACCURATE TO WITHIN 040 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 110 NM NORTHEAST QUADRANT
115 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 175 NM NORTHEAST QUADRANT
185 NM SOUTHEAST QUADRANT
140 NM SOUTHWEST QUADRANT
155 NM NORTHWEST QUADRANT
REPEAT POSIT: 19.9S 171.1E
---
FORECASTS:
12 HRS, VALID AT:
220600Z --- 22.1S 172.0E
MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 110 NM NORTHEAST QUADRANT
115 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT
190 NM SOUTHEAST QUADRANT
150 NM SOUTHWEST QUADRANT
160 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 155 DEG/ 17 KTS
---
24 HRS, VALID AT:
221800Z --- 25.1S 173.6E
MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 110 NM NORTHEAST QUADRANT
115 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT
190 NM SOUTHEAST QUADRANT
165 NM SOUTHWEST QUADRANT
170 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 145 DEG/ 21 KTS
---
36 HRS, VALID AT:
230600Z --- 28.4S 176.4E
MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 064 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 100 NM NORTHEAST QUADRANT
110 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT
185 NM SOUTHEAST QUADRANT
140 NM SOUTHWEST QUADRANT
150 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 135 DEG/ 24 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
231800Z --- 31.8S 179.8W
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 064 KT WINDS - 045 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 145 NM NORTHEAST QUADRANT
160 NM SOUTHEAST QUADRANT
130 NM SOUTHWEST QUADRANT
135 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 145 DEG/ 24 KTS
---
72 HRS, VALID AT:
241800Z --- 39.1S 172.4W
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
212100Z POSITION NEAR 20.5S 171.3E.
TROPICAL CYCLONE (TC) 17P (ATU), LOCATED APPROXIMATELY 295 NM EAST-
NORTHEAST OF NOUMEA, NEW CALEDONIA, HAS TRACKED SOUTHEASTWARD AT 09
KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION ESTIMATE IS
BASED ON SATELLITE FIXES FROM VARIOUS REPORTING AGENCIES AND A
211701Z SSMI IMAGE. THE CURRENT INTENSITY OF 95 KNOTS IS CONSISTENT
WITH DVORAK INTENSITY T-NUMBER ESTIMATES RANGING FROM 90 TO 102
KNOTS. TC 17P HAS UNDERGONE SOME STRUCTURAL CHANGE OVER THE PAST
TWELVE HOURS, WITH EROSION OF THE SOUTHWESTERN PORTION OF THE
EYEWALL NOW EVIDENT IN INFRARED SATELLITE IMAGERY. THESE STRUCTURAL
CHANGES HAVE RESULTED IN SLIGHT WEAKENING. HOWEVER, THE CYCLONE IS
EXPECTED TO MAINTAIN INTENSITY OR INTENSIFY A BIT OVER THE UPCOMING
24 HOURS AS STRONG UPPER LEVEL OUTFLOW AND PASSAGE OVER A WARM SEA
SURFACE ARREST THE CURRENT WEAKENING TREND. TC 17P IS TRACKING ALONG
THE WESTERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE TO THE EAST
AND IS EXPECTED TO ACCELERATE DURING THE FORECAST PERIOD AHEAD OF A
MID-LATITUDE TROUGH APPROACHING FROM THE SOUTHWEST. INCREASING
VERTICAL WIND SHEAR, ENTRAINMENT OF DRIER AIR, AND PASSAGE OVER
COOLER WATER WILL INDUCE THE FIRST PHASE OF EXTRATROPICAL TRANSITION
BY TAU 36. FAVORABLE INTERACTION WITH THE UPPER LEVEL FLOW PATTERN
AHEAD OF THE APPROACHING TROUGH WILL ENABLE TC 17P TO TRANSITION
INTO A STRONG EXTRATROPICAL LOW BY TAU 72. THE NUMERICAL MODEL
GUIDANCE REMAINS IN VERY GOOD AGREEMENT. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 211800Z IS 33 FEET. NEXT WARNINGS AT 220900Z AND 222100Z.//
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