SIO: TROPICAL CYCLONE ROBYN (23S)

[wyq614]

I see EC develop it...

Potential Cyclones:
There are no significant lows in the region. Thunderstorm activity is increasing
along a trough near 10S from 090E to 100E, and there are indications that a low
may form in the vicinity of 10S 090E later this week or over the weekend.

Likelihood of a tropical cyclone being in the Western Region:
Wednesday :Very Low
Thursday :Very Low
Friday :Low

http://www.bom.gov.au/weather/wa/foreca ... lone.shtml

[HURAKAN]

Latest

[HURAKAN]

Australian Government Bureau of Meteorology
Western Australia

Tropical Cyclone three-day outlook for the Western Region
Issued at 3:46pm WST on Thursday the 1st of April 2010
Valid until midnight WST Sunday


Existing Cyclones in the Western region:
Nil

Potential Cyclones:
While there are no significant lows in the region, a weak low appears to be
forming in the monsoon trough in the vicinity of 9S 93E. The low will most
likely be steered to the southwest in the next few days towards 90E and then be
slow moving. There is an increasing likelihood of development early next week.

Likelihood of a tropical cyclone being in the Western Region:
Friday :Low
Saturday :Low
Sunday :Moderate


NOTES: Development Potential is an estimate of the chance of each system being a
tropical cyclone in the Region for each day.
Very Low: less than 5% Low: 5% - 20%,
Moderate: 20% - 50% High: Over 50%

The Western Region refers to the Indian Ocean between Longitudes 90 -125E and
south of 10S.
Further information on Tropical Cyclones is available at:
http://www.bom.gov.au/weather/cyclone/

[HURAKAN]

AN AREA OF CONVECTION HAS PERSISTED NEAR 9.4S 92.5E,
APPROXIMATELY 305 NM WEST-NORTHWEST OF COCOS ISLANDS. A 010232Z
ASCAT PASS REVEALS AN AREA OF TIGHT TROUGHING WITH A BAND OF 20-25
KNOT WINDS ON THE POLEWARD SIDE OF THE TROUGH WHILE ANIMATED
MULTISPECTRAL SATELLITE IMAGERY SHOWS A PARTIALLY-EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION TO THE SOUTHWEST OF
THE SYSTEM CENTER. A 010034Z SSMIS MICROWAVE IMAGE ALSO DEPICTS
CURVED INFLOW ABOUT THE SYSTEM CENTER. ENVIRONMENTAL ANALYSIS
INDICATES THE SYSTEM HAS DIVERGENT OUTFLOW ALOFT BUT IS ALSO IN AN
AREA OF MODERATE VERTICAL WIND SHEAR CAUSED BY EASTERLY FLOW
EQUATORWARD OF THE SUBTROPICAL RIDGE AXIS. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1008 MB. DUE TO THE DISORGANIZED AND SHEARED
DEEP CONVECTION AS WELL AS A LACK OF GLOBAL MODEL DEVELOPMENT OVER
THE NEXT 24 HOURS, THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS POOR.

[HURAKAN]

Latest

[HURAKAN]

Latest

[HURAKAN]

01/2030 UTC 10.2S 92.7E T1.5/1.5 94S -- Southeast Indian

25 knots

[HURAKAN]

WTXS21 PGTW 020130
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 130
NM EITHER SIDE OF A LINE FROM 9.7S 92.8E TO 15.1S 92.4E WITHIN THE
NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUM-
BERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE
ESTIMATED TO BE 30 TO 35 KNOTS. METSAT IMAGERY AT 012330Z INDICATES
THAT A CIRCULATION CENTER IS LOCATED NEAR 10.7S 92.5E. THE SYSTEM IS
MOVING SOUTHWESTWARD AT 13 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 10.3S
92.8E IS NOW LOCATED NEAR 10.7S 92.5E, APPROXIMATELY 270 NM WEST-
NORTHWEST OF COCOS ISLAND. ANIMATED INFRARED SATELLITE IMAGERY SHOWS
AN AREA OF DEEP CONVECTION HAS CONTINUED TO BUILD TOWARDS A LOW
LEVEL CIRCULATION CENTER (LLCC), SUPPORTED BY A 011933Z AMSU-B PASS.
A RECENT 011505Z ASCAT PASS REVEALED A WELL DEFINED LLCC WITH WINDS
BETWEEN 20 AND 25 KNOTS ALONG THE WESTERN PERIPHERY. SURFACE CONDI-
TIONS THROUGHOUT THE AREA ARE FAVORABLE FOR FURTHER DEVELOPMENT.
UPPER LEVEL ANALYSIS INDICATES THE LLCC IS LOCATED EQUATORWARD OF A
SUBTROPICAL RIDGE AXIS, WHICH IS PROVIDING GOOD UPPER LEVEL DIVER-
GENCE AND MODERATE VERTICAL WIND SHEAR (VWS) NEAR THE LLCC. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 30 TO 35 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. BASED ON THE
INCREASING DEEP CONVECTION, DECREASING VWS, AND WELL DEFINED LLCC,
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
030130Z.//
NNNN

[HURAKAN]

WTXS31 PGTW 020900
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 23S (TWENTYTHREE) WARNING NR 001//
RMKS/
1. TROPICAL CYCLONE 23S (TWENTYTHREE) WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
020600Z --- NEAR 11.3S 92.5E
MOVEMENT PAST SIX HOURS - 190 DEGREES AT 05 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 11.3S 92.5E
---
FORECASTS:
12 HRS, VALID AT:
021800Z --- 12.2S 92.6E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 155 DEG/ 06 KTS
---
24 HRS, VALID AT:
030600Z --- 13.2S 93.1E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 020 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 145 DEG/ 05 KTS
---
36 HRS, VALID AT:
031800Z --- 14.1S 93.7E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 145 DEG/ 07 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
040600Z --- 15.3S 94.6E
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 - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 120 DEG/ 08 KTS
---
72 HRS, VALID AT:
050600Z --- 17.0S 97.5E
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 - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 115 DEG/ 07 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:
060600Z --- 18.1S 100.1E
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 120 HR POSIT: 140 DEG/ 06 KTS
---
120 HRS, VALID AT:
070600Z --- 19.8S 101.6E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
020900Z POSITION NEAR 11.5S 92.5E.
TROPICAL CYCLONE (TC) 23S, LOCATED APPROXIMATELY 260 NM WEST OF COCOS
ISLAND, AUSTRALIA, HAS TRACKED SOUTHWARD AT 05 KNOTS OVER THE PAST
SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS CONVECTIVE
BANDING HAS CONSOLIDATED AROUND THE LOW LEVEL CIRCULATION CENTER. THE
INITIAL POSITION IS EXTRAPOLATED FROM A 020022Z SSMIS MICROWAVE IMAGE
AND THE CURRENT INTENSITY IS BASED ON DVORAK ESTIMATES OF T2.5 FROM
PGTW, APRF AND KNES. UPPER LEVEL ANALYSIS INDICATES TC 23S IS JUST TO
THE NORTH OF A RIDGE AXIS IN AN AREA OF MODERATE EASTERLY VERTICAL
WIND SHEAR (VWS). THE CYCLONE IS EXPECTED TO TRACK SOUTH TO
SOUTHEASTWARD ALONG THE PERIPHERY OF A LOW- TO MID-LEVEL NEAR
EQUATORIAL RIDGE TO THE EAST OVER THE NEXT 48 HOURS. 22S WILL
GRADUALLY INTENSIFY AS IT TRACKS UNDER THE UPPER LEVEL RIDGE AXIS
WHERE THE VWS VALUES ARE AT A MINIMUM. AFTER TAU 72, THE SYSTEM WILL
DEFLECT MORE EASTWARD AS A MID-LATITUDE TROUGH APPROACHES FROM THE
SOUTHWEST. TC 22S WILL RAPIDLY WEAKEN WITH INCREASED VWS ASSOCIATED
WITH THE STRONG WESTERLIES. THE AVAILABLE NUMERIC MODELS ARE IN LOOSE
AGREEMENT WITH THIS TRACK FORECAST WITH THE EXCEPTION OF GFS, WHICH
INITIALLY TRACKS A WEAK VORTEX TO THE SOUTHWEST BEFORE MERGING WITH
THE MAIN ENVELOPE TO A SOUTHEAST TRAJECTORY. THE MODEL TRACKS SPREAD
OUT SIGNIFICANTLY IN SPEED AND DIRECTION AFTER TAU 72. THIS WARNING
SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN 020121Z APR 10 TROPICAL
CYCLONE FORMATION ALERT (WTXS21 PGTW 020130 ) MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 020600Z IS 8 FEET. NEXT WARNINGS AT 022100Z AND 030900Z.//
NNNN

[HURAKAN]

02/0830 UTC 11.5S 92.3E T2.5/2.5 23S -- Southeast Indian

35 knots

[HURAKAN]

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0831 UTC 02/04/2010
Name: Tropical Low
Identifier: 12U
Data At: 0600 UTC
Latitude: 11.0S
Longitude: 92.3E
Location Accuracy: within 30 nm [55 km]
Movement Towards: southwest [224 deg]
Speed of Movement: 6 knots [11 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 1000 hPa
Radius of 34-knot winds NE quadrant:
Radius of 34-knot winds SE quadrant:
Radius of 34-knot winds SW quadrant:
Radius of 34-knot winds NW quadrant:
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: T2.5/2.5/D1.0/24HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Medium
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 02/1800: 11.9S 92.1E: 060 [110]: 035 [065]: 997
+24: 03/0600: 12.5S 92.0E: 090 [165]: 040 [075]: 994
+36: 03/1800: 13.1S 92.0E: 120 [225]: 050 [095]: 988
+48: 04/0600: 13.8S 92.1E: 155 [285]: 060 [110]: 981
+60: 04/1800: 14.6S 92.3E: 200 [375]: 060 [110]: 981
+72: 05/0600: 15.3S 93.1E: 250 [465]: 060 [110]: 981
REMARKS:
Deep convection has improved near and west of the low level circulation centre
in the past 18 hours, despite ongoing moderate to strong easterly vertical wind
shear in excess of 30 knots. Ascat images indicate 30 knot winds in the
southwestern quadrant [downshear].

Dvorak DT=2.5 based on -0.4 wrap on curved band [although shear pattern could
even suggest a 3.0 possible]. MET/PAT agree.

Given the persisting deep convection with very cold cloud tops through the day,
further intensification expected especially as the low moves to the south
southwest into a zone of lower wind shear. Tropical cyclone intensity is hence
expected during the overnight period [although a region of 35 knots in the
southwestern quadrant is likely from now on]. Steering flow remains light with a
ridge remaining weak in the forecast period. Slow south southwesterly movent is
forecast. On Sunday a strengthening mid-level trough to the south may help to
deepen the system and move it to the south southeast keeping the system east of
90E within the Australian region.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 02/1300 UTC by Perth TCWC.

[HURAKAN]

Latest

[HURAKAN]

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1321 UTC 02/04/2010
Name: Tropical Low
Identifier: 12U
Data At: 1200 UTC
Latitude: 11.6S
Longitude: 92.3E
Location Accuracy: within 30 nm [55 km]
Movement Towards: south southwest [204 deg]
Speed of Movement: 6 knots [11 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 1000 hPa
Radius of 34-knot winds NE quadrant:
Radius of 34-knot winds SE quadrant:
Radius of 34-knot winds SW quadrant:
Radius of 34-knot winds NW quadrant:
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: T2.5/2.5/D1.0/24HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Medium
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 03/0000: 12.7S 92.3E: 060 [110]: 040 [075]: 995
+24: 03/1200: 13.5S 92.4E: 090 [165]: 050 [095]: 988
+36: 04/0000: 14.1S 92.7E: 120 [220]: 060 [110]: 981
+48: 04/1200: 14.6S 93.1E: 155 [285]: 065 [120]: 977
+60: 05/0000: 15.1S 93.6E: 200 [370]: 065 [120]: 977
+72: 05/1200: 15.4S 94.1E: 250 [465]: 065 [120]: 977
REMARKS:
Deep convection has persisted near and southwest of the low level circulation
centre in the past 24 hours, despite ongoing moderate vertical wind shear of
between 20/30 knots.

Difficult to assign a DT. Shear pattern would yield DT of 3.0. MET is 2.5 based
on developing trend with PAT of 2.5, so FT/CI set to 2.5.

Given the persisting deep convection with very cold cloud tops through the day,
further intensification is expected especially as the low moves to the south
into a zone of lower wind shear. Tropical cyclone intensity is possible during
the overnight period [although a region of 35 knot winds in the southwestern
quadrant is likely to exist already]. Steering flow remains light with a ridge
remaining weak in the forecast period. Slow southerly movement is forecast. On
Monday the passage of a mid-level trough to the south may help to deepen the
system and steer it to the south southeast keeping the system east of 90E within
the Australian region.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 02/1900 UTC by Perth TCWC.

[HURAKAN]

02/1430 UTC 12.4S 91.8E T2.5/2.5 23S -- Southeast Indian

35 knots

[KWT]

Yeah 35kts looks about right to me as well, tracking southwards but its at quite a high latitude and thus its got some decent waters to strengthen in, if the shear eases off at all.

[HURAKAN]

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0111 UTC 03/04/2010
Name: Tropical Cyclone Robyn
Identifier: 12U
Data At: 0000 UTC
Latitude: 12.9S
Longitude: 92.2E
Location Accuracy: within 25 nm [45 km]
Movement Towards: south [191 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: 70 nm [130 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/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: 03/1200: 13.7S 92.2E: 045 [085]: 045 [085]: 991
+24: 04/0000: 14.3S 92.2E: 075 [140]: 055 [100]: 985
+36: 04/1200: 15.2S 92.3E: 105 [195]: 060 [110]: 982
+48: 05/0000: 15.9S 92.6E: 135 [250]: 065 [120]: 977
+60: 05/1200: 16.1S 93.5E: 165 [305]: 070 [130]: 974
+72: 06/0000: 16.2S 94.3E: 195 [360]: 075 [140]: 969
REMARKS:
Very deep convection continues near and southwest of the low level circulation
centre with improvement in banding evident on recent IR imagery. The
circulation has been hampered by moderate ENE vertical wind shear but this has
now dropped below 20 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 0.6 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 . During Sunday 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: 03/0700 UTC by Perth TCWC.

[HURAKAN]

Latest

[HURAKAN]

02/2030 UTC 13.1S 91.9E T3.0/3.0 23S -- Southeast Indian

45 knots

[HURAKAN]

WTXS31 PGTW 022100
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 23S (TWENTYTHRE) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 23S (TWENTYTHRE) WARNING NR 002
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
021800Z --- NEAR 12.7S 92.4E
MOVEMENT PAST SIX HOURS - 180 DEGREES AT 07 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
REPEAT POSIT: 12.7S 92.4E
---
FORECASTS:
12 HRS, VALID AT:
030600Z --- 13.4S 92.5E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 165 DEG/ 04 KTS
---
24 HRS, VALID AT:
031800Z --- 14.1S 92.7E
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 - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 155 DEG/ 04 KTS
---
36 HRS, VALID AT:
040600Z --- 14.8S 93.0E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 145 DEG/ 05 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
041800Z --- 15.6S 93.6E
MAX SUSTAINED WINDS - 080 KT, GUSTS 100 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
020 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 120 DEG/ 04 KTS
---
72 HRS, VALID AT:
051800Z --- 16.5S 95.1E
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
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 125 DEG/ 02 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:
061800Z --- 17.0S 95.8E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 120 HR POSIT: 155 DEG/ 02 KTS
---
120 HRS, VALID AT:
071800Z --- 17.6S 96.1E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
022100Z POSITION NEAR 12.9S 92.4E.
TROPICAL CYCLONE (TC) 23S, LOCATED APPROXIMATELY 265 NM WEST OF THE
COCOS ISLANDS, AUSTRALIA, HAS TRACKED SOUTHWARD AT 07 KNOTS OVER THE
PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY AND RECENT
MICROWAVE IMAGERY INDICATE A CONSOLIDATING LOW-LEVEL CIRCULATION
CENTER (LLCC) WITH IMPROVED POLEWARD OUTFLOW. CONSEQUENTLY, DEEP
CONVECTION HAS EXPANDED OVER THE PAST 06 HOURS WITH THE LLCC LOCATED
ALONG THE NORTHEASTERN EDGE DUE TO MODERATE EASTERLY VERTICAL WIND
SHEAR. THE CURRENT INTENSITY IS BASED ON THE AVERAGE OF DVORAK
ESTIMATES RANGING FROM 35 TO 45 KNOTS. THERE IS MARGINAL CONFIDENCE
IN THE CURRENT POSITION AND MOTION BASED ON THE LACK OF STRONG
CONVECTIVE BANDING AND DEARTH OF HIGH-RESOLUTION MICROWAVE IMAGERY.
TC 23S IS CURRENTLY TRACKING SOUTHWARD ALONG THE WESTERN PERIPHERY
OF THE WEAK LOW- TO MID-LEVEL SUBTROPICAL RIDGE (STR). THE SYSTEM IS
EXPECTED TO TRACK INCREASINGLY SOUTHEASTWARD AS THE SOUTHERN
PERIPHERY OF THE STR ERODES WITH THE PASSAGE OF A MIDLATITUDE
SHORTWAVE TROUGH. TC 23S IS EXPECTED TO INTENSIFY UP TO A PEAK
INTENSITY OF 80 KNOTS NEAR TAU 48 DUE TO THE ENHANCED POLEWARD
OUTFLOW AND FAVORABLE SST AND OCEAN HEAT CONTENT. AFTER TAU 72, THE
SYSTEM SHOULD WEAKEN SIGNIFICANTLY DUE TO STRONG VERTICAL WIND SHEAR
PRODUCED BY A COMBINATION OF UPPER-LEVEL WESTERLIES AND LOW-LEVEL
EASTERLY FLOW (RIDGE BUILDING SOUTH OF THE SYSTEM AFTER THE FRONTAL
SYSTEM MOVES INTO WESTERN AUSTRALIA). IN THE EXTENDED TAUS, TC 23S
IS FORECAST TO WEAKEN BELOW 35 KNOTS AND DE-COUPLE AND WILL LIKELY
TURN WESTWARD UNDER THE STEERING INFLUENCE OF THE LOW-LEVEL RIDGE.
ALL OF THE DYNAMIC MODELS SUPPORT THIS TRACK WITH DIFFERENCES IN THE
TIMING OF THE TURN WESTWARD. THE UKMO MODEL REMAINS AN OUTLIER AND
INDICATES AN ERRONEOUS EASTWARD TRACK INTO THE STR AFTER TAU 48
THEREFORE THIS FORECAST IS POSITIONED WEST OF THE MODEL CONSENSUS
FROM TAU 72-120. THIS FORECAST REPRESENTS A SIGNIFICANT CHANGE FROM
THE PREVIOUS FORECAST BASED ON A LARGE SHIFT IN SEVERAL MODELS TO A
SLOWER, MORE REALISTIC TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
021800Z IS 12 FEET. NEXT WARNINGS AT 030900Z AND 032100Z.//

[HURAKAN]

NRL - 45 knots