SIO: TROPICAL CYCLONE ROBYN (23S)

#21 Postby **HURAKAN** » Sat Apr 03, 2010 6:02 am

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0709 UTC 03/04/2010
Name: Tropical Cyclone Robyn
Identifier: 12U
Data At: 0600 UTC
Latitude: 13.4S
Longitude: 92.1E
Location Accuracy: within 25 nm [45 km]
Movement Towards: south [190 deg]
Speed of Movement: 5 knots [9 km/h]
Maximum 10-Minute Wind: 40 knots [75 km/h]
Maximum 3-Second Wind Gust: 55 knots [100 km/h]
Central Pressure: 995 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 80 nm [150 km]
Radius of 34-knot winds SW quadrant: 120 nm [220 km]
Radius of 34-knot winds NW quadrant: 80 nm [150 km]
Radius of 48-knot winds NE quadrant:
Radius of 48-knot winds SE quadrant:
Radius of 48-knot winds SW quadrant:
Radius of 48-knot winds NW quadrant:
Radius of 64-knot winds:
Radius of Maximum Winds: N/A
Dvorak Intensity Code: T3.0/3.0/D0.5/24HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 03/1800: 14.3S 91.9E: 045 [085]: 045 [085]: 992
+24: 04/0600: 15.0S 91.7E: 075 [140]: 055 [100]: 985
+36: 04/1800: 15.8S 91.8E: 105 [195]: 060 [110]: 982
+48: 05/0600: 16.3S 92.0E: 135 [250]: 065 [120]: 977
+60: 05/1800: 16.4S 92.4E: 165 [305]: 070 [130]: 973
+72: 06/0600: 16.6S 92.4E: 195 [360]: 075 [140]: 967
REMARKS:
Very deep convection continues near and southwest of the low level circulation
centre with a broad band evident on recent imagery. While the circulation's
history has been hampered by moderate to strong ENE vertical wind shear, this is
now dropping to about 15 knots and the LLCC is now more aligned with convection
suggesting that further intensification is likely as guidance suggests.

Dvorak intensity CI/FT/DT=3.0 based on 0.5-0.6 curved band wrap, MET/PT agree,
also supported by AMSU estimates of -50 knot [1min mean].

Continued southerly motion is forecast with light steering flow with a ridge to
the south remaining weak. Later on Sunday and during Monday a deepening
mid-level trough to the south may help to deepen the system and steer it to the
southeast for a period. There is then divergence in track predictions, although
a recurvature to the west and weakening seems the most likely scenario at this
stage.

The cyclone is likely to remain over open waters and does not pose a risk to
island or coastal communities.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 03/1300 UTC by Perth TCWC.

#22 Postby **HURAKAN** » Sat Apr 03, 2010 6:21 am

NRL - 55 knots

#23 Postby **HURAKAN** » Sat Apr 03, 2010 6:22 am

WTXS31 PGTW 030900
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 23S (ROBYN) WARNING NR 003//
RMKS/
1. TROPICAL CYCLONE 23S (ROBYN) WARNING NR 003
01 ACTIVE TROPICAL CYCLONE IN SOUTH IO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
030600Z --- NEAR 13.0S 92.2E
MOVEMENT PAST SIX HOURS - 180 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
REPEAT POSIT: 13.0S 92.2E
---
FORECASTS:
12 HRS, VALID AT:
031800Z --- 13.6S 92.2E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 170 DEG/ 03 KTS
---
24 HRS, VALID AT:
040600Z --- 14.2S 92.3E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 005 NM NORTHEAST QUADRANT
005 NM SOUTHEAST QUADRANT
005 NM SOUTHWEST QUADRANT
005 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 180 DEG/ 03 KTS
---
36 HRS, VALID AT:
041800Z --- 14.7S 92.3E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 195 DEG/ 02 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
050600Z --- 15.1S 92.2E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 215 DEG/ 01 KTS
---
72 HRS, VALID AT:
060600Z --- 15.5S 91.9E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
RADIUS OF 034 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 260 DEG/ 01 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:
070600Z --- 15.6S 91.3E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
030900Z POSITION NEAR 13.2S 92.2E.
TROPICAL CYCLONE (TC) 23S, LOCATED APPROXIMATELY 280 NM WEST-
SOUTHWEST OF THE COCOS ISLANDS, AUSTRALIA, HAS SLOWED DOWN AND
TRACKED SOUTHWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED
WATER VAPOR IMAGERY SHOWS CONVECTIVE SYMMETRICAL BANDING HAVE
CONSOLIDATED OVER THE LOW-LEVEL CIRCULATION CENTER (LLCC) WITH
IMPROVED RADIAL OUTFLOW. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM
HAS DRIFTED UNDER THE RIDGE AXIS IN AN AREA OF LOW VERTICAL WIND
SHEAR (VWS). THE CURRENT INTENSITY IS BASED ON THE PGTW DVORAK
ESTIMATE OF T3.0. THE CURRENT POSITION IS EXTRAPOLATED FROM RECENT
MICROWAVE IMAGERY AND FROM A 030331Z ASCAT SCATTEROMETRY PASS. TC 23S
IS EXPECTED TO INTENSIFY IN THE SHORT TERM AND CONTINUE TRACKING
SLOWLY SOUTHWARD ALONG THE WESTERN PERIPHERY OF A WEAK STEERING RIDGE
TO THE EAST, OVER THE NEXT 48 TO 72 HOURS. AFTER TAU 72, THE SYSTEM
WILL BE EXPOSED TO STRONG WESTERLY VWS, DECOUPLING THE LLCC FROM THE
MAIN CONVECTION. THE REMNANT LOW WILL THEN DRIFT WESTWARD, STEERED BY
AN EASTWARD-MOVING SUBTROPICAL RIDGE TO THE SOUTH, AND DISSIPATE AS A
SIGNIFICANT TROPICAL CYCLONE OVER WATER BY TAU 96. THE MAJORITY OF
THE DYNAMIC MODELS SUPPORT THIS TRACK WITH DIFFERENCES IN THE SPEED
AND TIMING OF THE WESTWARD TRACK. WBAR AND GFS FORECAST THE SYSTEM TO
SURVIVE THE STRONG WESTERLY VWS AND TRACK SOUTHEASTWARD WITH THE
MID-LEVEL FLOW. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 030600Z IS 14
FEET. NEXT WARNINGS AT 032100Z AND 040900Z.//
NNNN

#24 Postby **HURAKAN** » Sat Apr 03, 2010 7:48 pm

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1817 UTC 03/04/2010
Name: Tropical Cyclone Robyn
Identifier: 12U
Data At: 1800 UTC
Latitude: 14.2S
Longitude: 91.9E
Location Accuracy: within 25 nm [45 km]
Movement Towards: south southwest [194 deg]
Speed of Movement: 4 knots [8 km/h]
Maximum 10-Minute Wind: 45 knots [85 km/h]
Maximum 3-Second Wind Gust: 65 knots [120 km/h]
Central Pressure: 990 hPa
Radius of 34-knot winds NE quadrant: 90 nm [165 km]
Radius of 34-knot winds SE quadrant: 90 nm [165 km]
Radius of 34-knot winds SW quadrant: 120 nm [220 km]
Radius of 34-knot winds NW quadrant: 90 nm [165 km]
Radius of 48-knot winds NE quadrant:
Radius of 48-knot winds SE quadrant:
Radius of 48-knot winds SW quadrant:
Radius of 48-knot winds NW quadrant:
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T3.0/3.0/D0.5/24HRS
Pressure of outermost isobar: 1004 hPa
Radius of outermost closed isobar: 120 nm [220 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 04/0600: 15.0S 91.5E: 055 [100]: 050 [095]: 987
+24: 04/1800: 15.7S 91.4E: 085 [155]: 060 [110]: 979
+36: 05/0600: 16.3S 91.5E: 115 [215]: 065 [120]: 975
+48: 05/1800: 16.7S 91.5E: 150 [280]: 070 [130]: 971
+60: 06/0600: 17.1S 91.4E: 200 [370]: 075 [140]: 967
+72: 06/1800: 17.3S 90.9E: 245 [455]: 070 [130]: 971
REMARKS:
Very deep convection continues near and west of the low level circulation
centre. While the circulation's history has been hampered by moderate to strong
ENE vertical wind shear, this has now dropped to about 10 to 15 knots and the
LLCC is now more aligned with convection, suggesting that further
intensification is likely.

Continued southerly motion is forecast with light steering flow with a ridge to
the south remaining weak. Later on Sunday and during Monday a deepening
mid-level trough to the south may help to deepen the system and steer it to the
southeast for a period. There is then some divergence in track predictions,
although a recurvature to the west and weakening seems the most likely scenario
at this stage.

The cyclone is likely to remain over open waters and does not pose a risk to
island or coastal communities.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 04/0100 UTC by Perth TCWC.

#25 Postby **HURAKAN** » Sat Apr 03, 2010 7:49 pm

NRL - 50 knots

#26 Postby **HURAKAN** » Sat Apr 03, 2010 7:54 pm

WTXS31 PGTW 032100
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 23S (ROBYN) WARNING NR 004//
RMKS/
1. TROPICAL CYCLONE 23S (ROBYN) WARNING NR 004
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
031800Z --- NEAR 14.0S 92.5E
MOVEMENT PAST SIX HOURS - 170 DEGREES AT 05 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
REPEAT POSIT: 14.0S 92.5E
---
FORECASTS:
12 HRS, VALID AT:
040600Z --- 14.8S 92.3E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 185 DEG/ 04 KTS
---
24 HRS, VALID AT:
041800Z --- 15.6S 92.2E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 175 DEG/ 04 KTS
---
36 HRS, VALID AT:
050600Z --- 16.4S 92.3E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 145 DEG/ 02 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
051800Z --- 16.7S 92.5E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 225 DEG/ 02 KTS
---
72 HRS, VALID AT:
061800Z --- 17.2S 92.0E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 96 HR POSIT: 260 DEG/ 03 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:
071800Z --- 17.4S 90.7E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
032100Z POSITION NEAR 14.2S 92.5E.
TROPICAL CYCLONE (TC) 23S, LOCATED APPROXIMATELY 280 NM
WEST-SOUTHWEST OF THE COCOS ISLANDS, AUSTRALIA, HAS TRACKED
SOUTHWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED
INFRARED SATELLITE IMAGERY AND A 031808Z TRMM 37 GHZ IMAGE
INDICATE SLIGHT WEAKENING OVER THE PAST 12 HOURS WITH A
DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) SHEARED EAST
OF THE DEEP CONVECTION. THE CURRENT POSITION IS BASED
PRIMARILY ON THIS TRMM IMAGE WITH GOOD CONFIDENCE. THERE
IS MARGINAL CONFIDENCE IN THE EXACT 12-HOUR MOTION BASED
ON THE SHEARED NATURE OF THE SYSTEM BUT TC 23S IS TRACKING
GENERALLY SOUTHWARD ALONG THE WESTERN PERIPHERY OF THE
WEAK LOW- TO MID-LEVEL SUBTROPICAL RIDGE (STR). THE CURRENT
INTENSITY IS SLIGHTLY HIGHER THAN THE FINAL-T DVORAK
ESTIMATES OF 45 KNOTS BASED ON A CI OF 55 KNOTS FROM PGTW.
THIS MOTION SHOULD CONTINUE THROUGH TAU 36 WITH A MORE SOUTH-
SOUTHEASTWARD, SLOWER TRACK EXPECTED NEAR TAU 48 AS A
RESULT OF AN APPROACHING MIDLATITUDE SHORTWAVE TROUGH AND
INCREASING VERTICAL WIND SHEAR (VWS). TC 23S IS FORECAST
TO WEAKEN RAPIDLY UNDER STRONG VWS AND WILL TURN WESTWARD
UNDER THE STEERING INFLUENCE OF THE LOW-LEVEL RIDGE
SOUTH OF THE SYSTEM. THERE IS SIGNIFICANT UNCERTAINTY
IN THE TIMING OF THIS WESTWARD TURN, HOWEVER, ALL AVAILABLE
MODEL TRACKERS, EXCEPT WBAR, SUPPORT THE TURN BETWEEN
15-17S. WBAR INDICATES A RE-CURVE SCENARIO WHICH APPEARS
HIGHLY UNLIKELY DUE TO THE STRONG VWS AND BROAD LOW-LEVEL
HIGH EXPECTED TO BUILD SOUTH OF THE SYSTEM AFTER TAU 24.
THIS FORECAST IS IN CLOSE AGREEMENT WITH THE MODEL CONSENSUS.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 031800Z IS 16 FEET.
NEXT WARNINGS AT 040900Z AND 042100Z.//
NNNN

#27 Postby **HURAKAN** » Sat Apr 03, 2010 8:56 pm

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0102 UTC 04/04/2010
Name: Tropical Cyclone Robyn
Identifier: 12U
Data At: 0000 UTC
Latitude: 14.2S
Longitude: 92.4E
Location Accuracy: within 30 nm [55 km]
Movement Towards: south [180 deg]
Speed of Movement: 3 knots [6 km/h]
Maximum 10-Minute Wind: 45 knots [85 km/h]
Maximum 3-Second Wind Gust: 65 knots [120 km/h]
Central Pressure: 990 hPa
Radius of 34-knot winds NE quadrant: 90 nm [165 km]
Radius of 34-knot winds SE quadrant: 90 nm [165 km]
Radius of 34-knot winds SW quadrant: 120 nm [220 km]
Radius of 34-knot winds NW quadrant: 120 nm [220 km]
Radius of 48-knot winds NE quadrant:
Radius of 48-knot winds SE quadrant:
Radius of 48-knot winds SW quadrant:
Radius of 48-knot winds NW quadrant:
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T3.0/3.0/S0.0/24HRS
Pressure of outermost isobar: 1004 hPa
Radius of outermost closed isobar: 120 nm [220 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 04/1200: 14.8S 92.3E: 060 [110]: 050 [095]: 986
+24: 05/0000: 15.3S 92.5E: 090 [165]: 060 [110]: 979
+36: 05/1200: 15.9S 92.9E: 120 [220]: 065 [120]: 975
+48: 06/0000: 16.2S 92.7E: 155 [285]: 065 [120]: 975
+60: 06/1200: 16.4S 92.1E: 200 [370]: 065 [120]: 975
+72: 07/0000: 16.4S 91.3E: 250 [465]: 065 [120]: 976
REMARKS:
The system has been relocated on receipt of TRMM 1808 UTC microwave image with
the F-16 1247 UTC and 1146 UTC images supporting this relocation.

Very deep convection continues near and west of the low level circulation
centre. The system is now located in low shear with UW-CIMSS at 0000 UTC
indicating about 8 knots of NNE shear. Robyn is likely to slowly intensify in
this low shear environment and favourable SSTs.

Dvorak: Recent EIR imagery suggests 0.6 wrap [curved band pattern] giving a DT
of 3.0. 24hr trend is W- giving a MET of 2.5 but PAT is 3.0. Hence FT/CI remains
at 3.0.

Continued southerly motion is forecast with light steering flow with a ridge to
the south remaining weak. Later on Sunday and during Monday a deepening
mid-level trough to the south may help to deepen the system and steer it to the
southeast for a period. On Tuesday a mid-level ridge is likely to develop to the
south and steer the weakening system to the west.

The cyclone is likely to remain over open waters and does not pose a risk to
island or coastal communities.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 04/0700 UTC by Perth TCWC.

#28 Postby **HURAKAN** » Sun Apr 04, 2010 5:47 am

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0654 UTC 04/04/2010
Name: Tropical Cyclone Robyn
Identifier: 12U
Data At: 0600 UTC
Latitude: 14.5S
Longitude: 92.3E
Location Accuracy: within 25 nm [45 km]
Movement Towards: south southwest [198 deg]
Speed of Movement: 3 knots [6 km/h]
Maximum 10-Minute Wind: 50 knots [95 km/h]
Maximum 3-Second Wind Gust: 70 knots [130 km/h]
Central Pressure: 986 hPa
Radius of 34-knot winds NE quadrant: 90 nm [165 km]
Radius of 34-knot winds SE quadrant: 90 nm [165 km]
Radius of 34-knot winds SW quadrant: 120 nm [220 km]
Radius of 34-knot winds NW quadrant: 120 nm [220 km]
Radius of 48-knot winds NE quadrant: 20 nm [35 km]
Radius of 48-knot winds SE quadrant: 20 nm [35 km]
Radius of 48-knot winds SW quadrant: 20 nm [35 km]
Radius of 48-knot winds NW quadrant: 20 nm [35 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T3.5/3.5/D0.5/24HRS
Pressure of outermost isobar: 1004 hPa
Radius of outermost closed isobar: 120 nm [220 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 04/1800: 15.1S 92.1E: 055 [100]: 055 [100]: 982
+24: 05/0600: 15.5S 92.1E: 085 [155]: 065 [120]: 974
+36: 05/1800: 15.8S 91.9E: 115 [215]: 070 [130]: 970
+48: 06/0600: 16.1S 91.6E: 150 [280]: 065 [120]: 975
+60: 06/1800: 16.2S 90.9E: 200 [370]: 060 [110]: 979
+72: 07/0600: 16.3S 89.9E: 245 [455]: 055 [100]: 983
REMARKS:
Tropical Cyclone Robyn is located in low shear with UW-CIMSS at 0000 UTC
indicating about 8 knots of NNE shear. Robyn is likely to slowly intensify in
this low shear environment, favourable SSTs and good upper level outflow to the
south.

Dvorak: Recent visible imagery suggests 0.8 wrap [curved band pattern] giving a
DT of 3.5. 24hr trend is now D- giving a MET of 3.5 with PAT 3.5. Hence FT/CI
set to 3.5.

A general southward track is forecast with light steering flow with a ridge to
the south remaining weak. Later on Sunday and during Monday a deepening
mid-level trough to the south may help to deepen the system. On Tuesday a
mid-level ridge is likely to develop to the south and steer the system to the
west. It is then expected to weaken as shear increases.

The cyclone is likely to remain over open waters and does not pose a risk to
island or coastal communities.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 04/1300 UTC by Perth TCWC.

#29 Postby **HURAKAN** » Sun Apr 04, 2010 5:48 am

Latest

#30 Postby **HURAKAN** » Sun Apr 04, 2010 5:51 am

WTXS31 PGTW 040900
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 23S (ROBYN) WARNING NR 005//
RMKS/
1. TROPICAL CYCLONE 23S (ROBYN) WARNING NR 005
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
040600Z --- NEAR 15.2S 92.1E
MOVEMENT PAST SIX HOURS - 200 DEGREES AT 06 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
REPEAT POSIT: 15.2S 92.1E
---
FORECASTS:
12 HRS, VALID AT:
041800Z --- 16.2S 92.0E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 170 DEG/ 03 KTS
---
24 HRS, VALID AT:
050600Z --- 16.7S 92.1E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 005 NM NORTHEAST QUADRANT
005 NM SOUTHEAST QUADRANT
005 NM SOUTHWEST QUADRANT
005 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 160 DEG/ 02 KTS
---
36 HRS, VALID AT:
051800Z --- 17.0S 92.2E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 225 DEG/ 01 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
060600Z --- 17.2S 92.0E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 265 DEG/ 03 KTS
---
72 HRS, VALID AT:
070600Z --- 17.3S 90.9E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
040900Z POSITION NEAR 15.5S 92.1E.
TROPICAL CYCLONE (TC) 23S, LOCATED APPROXIMATELY 335 NM SOUTHWEST
OF THE COCOS ISLANDS, AUSTRALIA, HAS TRACKED SOUTH-SOUTHWESTWARD AT
05 KNOTS OVER THE PAST SIX HOURS. ANIMATED WATER VAPOR IMAGERY SHOWS
THE SYSTEM HAS MAINTAINED OVERALL CONVECTIVE BANDING AND OUTFLOW
ALTHOUGH IT HAS BEGUN TO ELONGATE ON THE SOUTHWEST QUADRANT, AN
INDICATION OF INCREASING VERTICAL WIND SHEAR (VWS). THE INITIAL
POSITION IS EXTRAPOLATED FROM A 040311Z AMSU-B MICROWAVE IMAGE AND
THE INITIAL INTENSITY IS AVERAGED FROM DVORAK ESTIMATES RANGING FROM
T3.0 TO T3.5 FROM PGTW/KNES AND APRF, RESPECTIVELY. TC 23S IS
EXPECTED TO CONTINUE TRACKING GENERALLY SOUTHWARD ALONG THE WESTERN
PERIPHERY OF THE WEAK LOW- TO MID-LEVEL SUBTROPICAL RIDGE (STR) UP TO
TAU 24 BEFORE IT GETS DEFLECTED MOMENTARILY TO THE SOUTHEAST IN
RESPONSE TO AN APPROACHING MID-LATITUDE SHORTWAVE TROUGH AND
INCREASING WESTERLY VWS. THE HIGH VWS WILL ERODE TC ROBYN AND CAUSE
IT TO WEAKEN RAPIDLY. THE REMNANT LOW LEVEL FEATURE WILL THEN TURN
WESTWARD UNDER THE STEERING INFLUENCE OF THE LOW-LEVEL RIDGE SOUTH OF
THE SYSTEM. THE AVAILABLE MODEL GUIDANCE, WITH THE EXCEPTION OF WBAR,
SUPPORT THE WESTWARD TURN WITH NOTABLE DIFFERENCES IN SPEED AND
TIMING. THIS TRACK FORECAST IS IN CLOSE AGREEMENT WITH THE MODEL
CONSENSUS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 040600Z IS 16 FEET.
NEXT WARNINGS AT 042100Z AND 050900Z.//
NNNN

KWT · #31 Postby **KWT** » Sun Apr 04, 2010 6:38 am

I'd personally argue this system is a little stronger then 50kts, esp looking at the vis image Hurakan has put up recently.

#32 Postby **HURAKAN** » Sun Apr 04, 2010 9:23 am

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1319 UTC 04/04/2010
Name: Tropical Cyclone Robyn
Identifier: 12U
Data At: 1200 UTC
Latitude: 14.8S
Longitude: 91.8E
Location Accuracy: within 25 nm [45 km]
Movement Towards: southwest [219 deg]
Speed of Movement: 4 knots [8 km/h]
Maximum 10-Minute Wind: 60 knots [110 km/h]
Maximum 3-Second Wind Gust: 85 knots [155 km/h]
Central Pressure: 980 hPa
Radius of 34-knot winds NE quadrant: 80 nm [150 km]
Radius of 34-knot winds SE quadrant: 100 nm [185 km]
Radius of 34-knot winds SW quadrant: 120 nm [220 km]
Radius of 34-knot winds NW quadrant: 110 nm [205 km]
Radius of 48-knot winds NE quadrant: 25 nm [45 km]
Radius of 48-knot winds SE quadrant: 25 nm [45 km]
Radius of 48-knot winds SW quadrant: 25 nm [45 km]
Radius of 48-knot winds NW quadrant: 25 nm [45 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T4.0/4.0/D1.0/24HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 05/0000: 15.5S 91.6E: 045 [085]: 065 [120]: 978
+24: 05/1200: 16.0S 91.6E: 075 [140]: 060 [110]: 980
+36: 06/0000: 16.1S 91.2E: 110 [205]: 055 [100]: 985
+48: 06/1200: 16.2S 90.4E: 140 [260]: 050 [095]: 988
+60: 07/0000: 16.4S 89.3E: 170 [315]: 045 [085]: 992
+72: 07/1200: 16.9S 88.2E: 210 [390]: 040 [075]: 995
REMARKS:
Deep convection persists on the western flank of Robyn with the mid-level centre
displaced down shear of the low level circulation centre as evidenced on the
SSMIS 1132UTC microwave image.

It appears that Tropical Cyclone Robyn is battling this moderate [-15knot NE
shear] and managing to intensify owing to strong upper level outflow poleward
and very deep convection.

Dvorak: DT=4.0 based on 0.9 [white] wrap curved band pattern, MET/PT agree. The
estimated intensity of 60 knots agrees with SATCON - latest AMSU intensity
indicates a stronger system as well. Some further intensification is expected
overnight with the deepening mid-latitude low enhancing the poleward outflow but
also likely to increase shear across the circulation. It seems unlikely the
system can become more vertically oriented to result in rapid intensification
however. During Monday this increasing NW shear is likely to adversely affect
the circulation so weakening is expected from late Monday onwards.

Motion should remain slow with some shift to the south southeast still a
possibility under the influence of that mid-level trough. However, from Tuesday
a westerly track is expected, the extent of which is dependent upon
weakening/shearing processes.

The cyclone is likely to remain over open waters and does not pose a risk to
island or coastal communities.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 04/1900 UTC by Perth TCWC.

#33 Postby **HURAKAN** » Sun Apr 04, 2010 9:24 am

Latest

#34 Postby **HURAKAN** » Sun Apr 04, 2010 12:40 pm

NRL - 60 knots

#35 Postby **HURAKAN** » Sun Apr 04, 2010 12:41 pm

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 04 APR 2010 Time : 163000 UTC
Lat : 15:12:26 S Lon : 91:39:39 E

CI# /Pressure/ Vmax
4.3 / 972.7mb/ 72.2kt

Final T# Adj T# Raw T#
4.3 4.3 3.2

Latitude bias adjustment to MSLP : +2.7mb

Center Temp : -64.7C Cloud Region Temp : -66.1C

Scene Type : UNIFORM CDO CLOUD REGION

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : INDIAN
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : MW HOLD
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

#36 Postby **P.K.** » Sun Apr 04, 2010 1:38 pm

12U up to 60kts.

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1833 UTC 04/04/2010
Name: Tropical Cyclone Robyn
Identifier: 12U
Data At: 1800 UTC
Latitude: 15.2S
Longitude: 91.6E
Location Accuracy: within 25 nm [45 km]
Movement Towards: south southwest [206 deg]
Speed of Movement: 4 knots [8 km/h]
Maximum 10-Minute Wind: 60 knots [110 km/h]
Maximum 3-Second Wind Gust: 85 knots [155 km/h]
Central Pressure: 980 hPa
Radius of 34-knot winds NE quadrant: 80 nm [150 km]
Radius of 34-knot winds SE quadrant: 100 nm [185 km]
Radius of 34-knot winds SW quadrant: 120 nm [220 km]
Radius of 34-knot winds NW quadrant: 90 nm [165 km]
Radius of 48-knot winds NE quadrant: 25 nm [45 km]
Radius of 48-knot winds SE quadrant: 25 nm [45 km]
Radius of 48-knot winds SW quadrant: 25 nm [45 km]
Radius of 48-knot winds NW quadrant: 25 nm [45 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T4.0/4.0/D1.0/24HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 05/0600: 15.8S 91.5E: 045 [085]: 065 [120]: 978
+24: 05/1800: 16.1S 91.5E: 075 [140]: 060 [110]: 980
+36: 06/0600: 16.2S 90.8E: 110 [205]: 050 [095]: 988
+48: 06/1800: 16.2S 89.8E: 140 [260]: 045 [085]: 990
+60: 07/0600: 16.6S 88.8E: 170 [315]: 040 [075]: 995
+72: 07/1800: 17.0S 87.5E: 210 [390]: 035 [065]: 998
REMARKS:
Deep convection persists on the western flank of Robyn with the mid-level centre
displaced down shear of the low level circulation centre as evidenced on the
SSMIS 1132UTC microwave image.

It appears that Tropical Cyclone Robyn is battling this moderate [-15knot] NE
shear and managing to intensify owing to strong upper level outflow poleward and
very deep convection.

Dvorak: DT=4.0 based on 0.9 [white] wrap curved band pattern, MET/PT agree. The
estimated intensity of 60 knots agrees with SATCON - latest AMSU intensity
indicates a stronger system as well. Some further intensification is expected
overnight with the deepening mid-latitude low enhancing the poleward outflow but
also likely to increase shear across the circulation. It seems unlikely the
system can become more vertically oriented to result in rapid intensification
however. During Monday this increasing NW shear is likely to adversely affect
the circulation so weakening is expected from late Monday onwards.

Motion should remain slow with some shift to the south southeast still a
possibility under the influence of that mid-level trough. However, from Tuesday
a westerly track is expected, the extent of which is dependent upon
weakening/shearing processes.

The cyclone is likely to remain over open waters and does not pose a risk to
island or coastal communities.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 05/0100 UTC by Perth TCWC.

#37 Postby **HURAKAN** » Sun Apr 04, 2010 7:49 pm

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0046 UTC 05/04/2010
Name: Severe Tropical Cyclone Robyn
Identifier: 12U
Data At: 0000 UTC
Latitude: 15.6S
Longitude: 91.4E
Location Accuracy: within 20 nm [35 km]
Movement Towards: south southwest [206 deg]
Speed of Movement: 4 knots [8 km/h]
Maximum 10-Minute Wind: 65 knots [120 km/h]
Maximum 3-Second Wind Gust: 90 knots [165 km/h]
Central Pressure: 976 hPa
Radius of 34-knot winds NE quadrant: 90 nm [165 km]
Radius of 34-knot winds SE quadrant: 90 nm [165 km]
Radius of 34-knot winds SW quadrant: 120 nm [220 km]
Radius of 34-knot winds NW quadrant: 120 nm [220 km]
Radius of 48-knot winds NE quadrant: 25 nm [45 km]
Radius of 48-knot winds SE quadrant: 25 nm [45 km]
Radius of 48-knot winds SW quadrant: 25 nm [45 km]
Radius of 48-knot winds NW quadrant: 25 nm [45 km]
Radius of 64-knot winds: 15 nm [30 km]
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T4.5/4.5/D1.5/24HRS
Pressure of outermost isobar: 1004 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 05/1200: 16.2S 91.3E: 050 [095]: 060 [110]: 979
+24: 06/0000: 16.5S 91.1E: 080 [150]: 055 [100]: 982
+36: 06/1200: 16.5S 90.4E: 110 [205]: 050 [095]: 986
+48: 07/0000: 16.5S 89.8E: 140 [260]: 045 [085]: 990
+60: 07/1200: 16.6S 88.8E: 190 [350]: 040 [075]: 993
+72: 08/0000: 16.8S 87.4E: 240 [445]: 030 [055]: 999
REMARKS:
Deep convection persists near the centre of Robyn. UW-CIMMS at 1800 UTC
indicated N'ly shear of about 14 knots. Strong upper level outflow poleward
assisted in intensifying the system overnight.

Dvorak: A weak ragged eye first appeared on the 2130 UTC MTSAT EIR image. The
2230 UTC image showed a pin hole eye. E no 6.0, E adj -1.0 so DT = 5.0. This
feature subsequently weakened on the 2330 UTC image.

MET was 4.0 based on D trend and PAT was 4.5. So FT/CI set to 4.5.

During Monday increasing NW shear is likely to adversely affect the circulation
so weakening is expected from late Monday onwards.

Motion should remain slow with some shift to the south southeast still a
possibility under the influence of a mid-level trough. However, from Tuesday a
westerly track is expected, the extent of which is dependent upon
weakening/shearing processes.

The cyclone is likely to remain over open waters and does not pose a risk to
island or coastal communities.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 05/0700 UTC by Perth TCWC.

#38 Postby **HURAKAN** » Sun Apr 04, 2010 7:51 pm

Latest

#39 Postby **HURAKAN** » Sun Apr 04, 2010 7:52 pm

Latest

KWT · #40 Postby **KWT** » Sun Apr 04, 2010 8:00 pm

Still looks decent, though I think there has been a slight decay of the presentation recently. 60kts looks about right though.

SIO: TROPICAL CYCLONE ROBYN (23S)

Re: SIO: TROPICAL CYCLONE ROBYN (23S)

Re: SIO: TROPICAL CYCLONE ROBYN (23S)

Re: SIO: TROPICAL CYCLONE ROBYN (23S)

Re: SIO: TROPICAL CYCLONE ROBYN (23S)

Re: SIO: TROPICAL CYCLONE ROBYN (23S)

Re: SIO: TROPICAL CYCLONE ROBYN (23S)

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