South Indian Ocean: Tropical Cyclone 17S

[HURAKAN]

07/1430 UTC 16.7S 105.9E T3.0/3.0 17S -- South Indian Ocean

Should be Nicholas soon.

[HURAKAN]

HIGH SEAS WEATHER WARNING FOR METAREA 10 ISSUED BY THE
AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING
CENTRE PERTH AT 1847UTC 7 FEBRUARY 2008

GALE WARNING FOR THE WESTERN AREA

Please be aware, wind gusts can be a further 40 percent stronger than the
averages given here, and maximum waves may be up to twice the height.

SITUATION
At 1800 UTC a Tropical Low was centred within 15 nautical miles of
latitude sixteen decimal four south [16.4S]
longitude one hundred and six decimal five east [106.5E]
Recent movement : east southeast at 5 knots
Central pressure: 992 hPa


AREA AFFECTED
Within 120 nautical miles of the centre in the western quadrant.

FORECAST
Clockwise winds 20/30 knots reaching 30/40 knots in the western quadrant with
rough to very rough seas and moderate swell.

Forecast positions
At 0600 UTC 08 February: Within 40 nautical miles of 16.4 south 107.8 east
Central pressure 992 hPa.
Winds to 30 knots near centre.
At 1800 UTC 08 February: Within 60 nautical miles of 16.3 south 109.1 east
Central pressure 992 hPa.
Winds to 30 knots near centre.

REMARKS
All ships in the area please send weather reports every three hours.
Regular weather observing ships use normal channels.
Other ships please use either email to tcwcwa@bom.gov.au or fax to +61892632261
or satellite to SAC 1241 through Land Earth Station Perth 312.

Next warning will be issued by 0100 UTC 08 February 2008.

WEATHER PERTH

I retract. "Nicholas" may have to wait!!

[Coredesat]

Environment seems fairly hostile at the moment. I'm not sure this will survive long enough to get a name.

[Squarethecircle]

Looks like a RBoC right now. I wouldn't give more than a day.

[Chacor]

AXAU01 APRF 080107
IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0106 UTC 08/02/2008
Name: Tropical Low
Data At: 0000 UTC
Latitude: 17.0S
Longitude: 106.7E
Location Accuracy: within 15 nm [28 km]
Movement Towards: southeast [132 deg]
Speed of Movement: 5 knots [10 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 992 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/S0.0/24HRS
Pressure of outermost isobar: 1002 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: 08/1200: 17.4S 107.4E: 035 [065]: 030 [055]: 992
+24: 09/0000: 17.3S 108.4E: 065 [120]: 030 [055]: 992
+36: 09/1200: 17.0S 110.0E: 090 [165]: 030 [055]: 992
+48: 10/0000: 16.4S 111.5E: 110 [205]: 030 [055]: 992
+60: 10/1200: 15.7S 114.0E: 140 [260]: 030 [055]: 992
+72: 11/0000: 16.4S 116.4E: 175 [325]: 040 [075]: 986
REMARKS:
The system continues to be hampered by moderate NE'ly shear with the low level
circulation centre exposed to the east of persisting deep convection. Dvorak
analysis indicates DT number of 2.5 using shear analysis averaged over 3 hours.
Ongoing shear should continue constrain development in the short term, however
in the longer term the system may intensify assisted by higher SSTs and lower
shear.
==
The next bulletin for this system will be issued by: 08/0700 UTC by Perth TCWC.

[Chacor]

Just what are the JTWC seeing here?

[HurricaneRobert]

Exposed low level circulation

[HURAKAN]

Going down, but we have seen this before with 17S!!!

[HURAKAN]

TROPICAL CYCLONE TECHNICAL SUMMARY: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0106 UTC 08/02/2008
Name: Tropical Low
Data At: 0000 UTC
Latitude: 17.0S
Longitude: 106.7E
Location Accuracy: within 15 nm (28 km)
Movement Towards: southeast (132 deg)
Speed of Movement: 5 knots (10 km/h)
Maximum 10-Minute Wind: 30 knots (55 km/h)
Maximum 3-Second Wind Gust: 45 knots (85 km/h)
Central Pressure: 992 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/S0.0/24HRS
Pressure of outermost isobar: 1002 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: 08/1200: 17.4S 107.4E: 035 (065): 030 (055): 992
+24: 09/0000: 17.3S 108.4E: 065 (120): 030 (055): 992
+36: 09/1200: 17.0S 110.0E: 090 (165): 030 (055): 992
+48: 10/0000: 16.4S 111.5E: 110 (205): 030 (055): 992
REMARKS:
The system continues to be hampered by moderate NE'ly shear with the low level circulation centre exposed to the east of persisting deep convection. Dvorak analysis indicates DT number of 2.5 using shear analysis averaged over 3 hours. Ongoing shear should continue constrain development in the short term, however in the longer term the system may intensify assisted by higher SSTs and lower shear.
Notes:
This product is issued every six hours; the Cyclone Advices (Watches and Warnings) are
usually issued more frequently and contain more useful information for coastal communities.

Time Conversion from UTC to local:
WST add 8 hrs (Add another hour for daylight saving)
CST add 9 hrs 30 min
EST add 10 hrs (Add another hour for daylight saving)
==
The next bulletin for this system will be issued by: 08/0700 UTC by Perth TCWC.

HIGH SEAS WEATHER WARNING FOR METAREA 10 ISSUED BY THE
AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING
CENTRE PERTH AT 0043UTC 8 FEBRUARY 2008

GALE WARNING FOR THE WESTERN AREA

Please be aware, wind gusts can be a further 40 percent stronger than the
averages given here, and maximum waves may be up to twice the height.

SITUATION
At 0000 UTC a tropical low was centred within 15 nautical miles of
latitude seventeen decimal zero south [17.0S]
longitude one hundred and six decimal seven east [106.7E]
Recent movement : southeast at 5 knots
Central pressure: 992 hPa


AREA AFFECTED
Within 120 nautical miles of the centre in the western quadrant.

FORECAST
Clockwise winds 20/30 knots reaching 30/40 knots in the western quadrant with
rough to very rough seas and moderate swell.

Forecast positions
At 1200 UTC 08 February: Within 35 nautical miles of 17.4 south 107.4 east
Central pressure 992 hPa.
Winds to 30 knots near centre.
At 0000 UTC 09 February: Within 65 nautical miles of 17.3 south 108.4 east
Central pressure 992 hPa.
Winds to 30 knots near centre.

REMARKS
All ships in the area please send weather reports every three hours.
Regular weather observing ships use normal channels.
Other ships please use either email to tcwcwa@bom.gov.au or fax to +61892632261
or satellite to SAC 1241 through Land Earth Station Perth 312.

Next warning will be issued by 0700 UTC 08 February 2008.

WEATHER PERTH

[Chacor]

AXAU01 APRF 080928
IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0928 UTC 08/02/2008
Name: Tropical Low
Data At: 0600 UTC
Latitude: 17.0S
Longitude: 107.2E
Location Accuracy: within 15 nm [28 km]
Movement Towards: east southeast [109 deg]
Speed of Movement: 5 knots [8 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 992 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/S0.0/24HRS
Pressure of outermost isobar: 1002 hPa
Radius of outermost closed isobar: 120 nm [220 km]
Storm Depth: Medium
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 08/1800: 16.9S 108.2E: 035 [065]: 030 [055]: 992
+24: 09/0600: 16.7S 109.3E: 065 [120]: 030 [055]: 992
+36: 09/1800: 16.4S 110.5E: 090 [165]: 030 [055]: 992
+48: 10/0600: 16.1S 112.2E: 110 [205]: 030 [055]: 992
+60: 10/1800: 15.9S 114.7E: 140 [260]: 030 [055]: 992
+72: 11/0600: 15.4S 116.6E: 170 [315]: 030 [055]: 992
REMARKS:
The system continues to be hampered by moderate NE'ly shear with the low level
circulation centre exposed to the east of persisting deep convection.
Dvorak analysis indicates DT number of 2.5 using shear analysis averaged over 3
hours.
Ongoing shear should continue to constrain development in the short term,
although gales are
possible in the western quadrant associated with the convection.
In the longer term intensification is possible if the shear does fall, however
most forecast
guidance suggests weakening in response to the development of another low
further to the east.
==
There will be no further bulletins for this system unless it intensifies.

[Pedro Fernández]

I think that there might be a nice battle wind-shear vs OHC - warmer waters. Which of them could win? Low Level Center is exposed but there are strong convective burst in the east flank of the low. Wind-shear around 30 KT...

Please, look at these images I have captured from RAMMB - CIRA:

[HURAKAN]

WTXS32 PGTW 081500
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 17S WARNING NR 004
03 ACTIVE TROPICAL CYCLONES IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
081200Z --- NEAR 17.2S 107.8E
MOVEMENT PAST SIX HOURS - 090 DEGREES AT 04 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 - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
REPEAT POSIT: 17.2S 107.8E
---
FORECASTS:
12 HRS, VALID AT:
090000Z --- 17.2S 108.6E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 070 DEG/ 05 KTS
---
24 HRS, VALID AT:
091200Z --- 16.9S 109.5E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 075 DEG/ 06 KTS
---
36 HRS, VALID AT:
100000Z --- 16.6S 110.7E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 065 DEG/ 07 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
101200Z --- 16.0S 112.0E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
---
REMARKS:
081500Z POSITION NEAR 17.2S 108.0E.
TROPICAL CYCLONE (TC) 17S (NONAME) LOCATED APPROXIMATELY 455 NM
NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED EAST AT 04 KNOTS OVER
THE PAST 06 HOURS. TC 17S HAS INTENSIFIED SLIGHTLY SINCE THE PREVIOUS
FORECAST WITH MAXIMUM SUSTAINED WIND SPEEDS ESTIMATED AT 40 KNOTS.
THIS INTENSITY IS SUPPORTED BY SATELLITE INTENSITY ESTIMATES OF 45
KNOTS AND RECENT SCATTEROMETER OBSERVATIONS RANGING FROM 25 TO 35
KNOTS. THE LOW LEVEL CIRCULATION CENTER FOR TC 17S REMAINS WELL
DEFINED, BUT IS PARTIALLY EXPOSED DUE TO MODERATE TO HIGH VERTICAL
WIND SHEAR WHICH IS THE PRIMARY INHIBITING FACTOR FOR SIGNIFICANT
INTENSIFICATION. THE SYSTEM WILL TRACK EASTWARD UNDER THE INFLUENCE
OF THE NEAR EQUATORIAL RIDGE THROUGH TAU 12 BEFORE TURNING TO A MORE
NORTHEASTERLY TRACK. THROUGHOUT THE FORECAST PERIOD THE SYSTEM WILL
INTENSIFY SLIGHTLY BUT WILL REMAIN INHIBITED BY THE VERTICAL WIND
SHEAR, AND IS NOT EXPECTED TO SURPASS 45 KNOTS IN THIS
FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 081200Z IS 14
FEET. NEXT WARNINGS AT 090300Z AND 091500Z. REFER TO TROPICAL CYCLONE
16S (HONDO) WARNINGS (WTXS31 PGTW) AND TROPICAL CYCLONE 18S (IVAN)
WARNINGS (WTXS33 PGTW) FOR TWELVE-HOURLY UPDATES.

08/1430 UTC 17.4S 107.8E T3.0/3.0 17S -- South Indian Ocean



Very intense convection. Call BoM. They unplugged 17S too early!!!

[HURAKAN]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 08 FEB 2008 Time : 153000 UTC
Lat : 17:13:51 S Lon : 108:01:22 E

CI# /Pressure/ Vmax
2.4 / 997.6mb/ 34.0kt

6hr-Avg T# 3hr-Avg T# Adj T# Raw T#
2.4 2.4 2.4 2.4

Latitude bias adjustment to MSLP : +0.0mb

Center Temp : +19.6C Cloud Region Temp : -13.9C

Scene Type : SHEAR (0.48^ TO DG)

Positioning Method : FORECAST INTERPOLATION

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

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

[HURAKAN]

Nice image!!!

[Sanibel]

Weird West to East pattern going on in Indian Ocean.

[Coredesat]

Looks like the shear won. The convection has fizzled out (the system may have weakened to the point where the convection is pulsing rather than constant):

[Chacor]

AXAU01 APRF 090044
IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0044 UTC 09/02/2008
Name: Tropical Low
Data At: 0000 UTC
Latitude: 17.4S
Longitude: 108.1E
Location Accuracy: within 20 nm [37 km]
Movement Towards: east southeast [122 deg]
Speed of Movement: 2 knots [4 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 990 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/S0.0/24HRS
Pressure of outermost isobar: 1000 hPa
Radius of outermost closed isobar: 90 nm [165 km]
Storm Depth: Shallow
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 09/1200: 17.5S 108.7E: 040 [075]: 030 [055]: 990
+24: 10/0000: 17.1S 110.1E: 065 [120]: 030 [055]: 990
+36: 10/1200: 16.5S 111.7E: 085 [155]: 030 [055]: 990
+48: 11/0000: 16.8S 113.8E: 105 [195]: 030 [055]: 990
+60: 11/1200: 18.0S 116.3E: 125 [230]: 030 [055]: 990
+72: 12/0000: 17.9S 116.3E: 155 [285]: 030 [055]: 990
REMARKS:
The system continues to be hampered by moderate NE'ly shear with the low level
circulation centre exposed to the northeast of persisting deep convection.
Dvorak analysis indicates DT number of 2.5 using shear analysis averaged over 3
hours.
Ongoing shear should continue to constrain development in the short term,
although gales are
possible in the western quadrant at times associated with the convection.
Most forecast guidance suggests this low will either weaken in response to the
development of another low further to the east or merge with this low on Monday.

==
The next bulletin for this system will be issued by: 09/0700 UTC by Perth TCWC.

[Crostorm]

[HURAKAN]

Adios mi amigo. Bye my friend.