SIO: Peta - Ex-Tropical

[supercane4867]

15kts 1007mb 16.3S 122.1E

[supercane4867]

A moderate to strong monsoon lies over the tropics which is causing enhanced
rainfall and moisture over Northern Australia. A
low is expected to develop in the monsoon trough over the western Kimberley on
Monday and move in a generally west direction into the Indian Ocean during
Tuesday. The risk of this low becoming a tropical cyclone increases during the
week when it is expected to be located north of the Pilbara coast.

Likelihood of this system being a tropical cyclone in the Western Region on:
Monday Low
Tuesday Moderate
Wednesday Moderate

[supercane4867]

AN AREA OF CONVECTION HAS PERSISTED NEAR 18.6S 122.1E,
APPROXIMATELY 495 NM EAST-NORTHEAST OF LEARMONTH, AUSTRALIA.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A DEVELOPING
LOW LEVEL CIRCULATION CENTER (LLCC) THAT HAS BEEN SLOWLY TRACKING
ALONG THE WESTERN COAST OF AUSTRALIA FOR THE PAST 12 TO 18 HOURS.
CONVECTION HAS BEEN FLARING OVER THE WESTERN HALF OF THE LLCC AS THE
AIR FLOW INTO THE LLCC PICKS UP MOISTURE FROM THE INDIAN OCEAN.
OBSERVATION.S NEAR THE LLCC INDICATE WIND SPEEDS ARE BETWEEN 10 TO 15
KNOTS WITH A CENTRAL PRESSURE NEAR 1002 MB. UPPER LEVEL ANALYSIS
INDICATES THE LLCC IS LOCATED BENEATH A BUILDING ANTICYCLONE, WHICH
IS PROVIDING LOW (5 TO 10 KNOTS) VERTICAL WIND SHEAR (VWS) AND GOOD
RADIAL OUTFLOW. SEA SURFACE TEMPERATURES (SSTS) OFF THE COAST ARE 29
TO 30 DEGREES CELSIUS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED
AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE
NEAR 1002 MB. DUE TO THE GOOD LOW LEVEL ORGANIZATION AND THE CLOSE
PROXIMITY OF THE LLCC TO THE WARM INDIAN OCEAN WATERS, THE POTENTIAL
FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE
NEXT 24 HOURS IS MEDIUM.

[Hurricane_Luis]

Invest 93S, Expected to strengthen into Tropical Cyclone Peta

[Extratropical94]

IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1850 UTC 22/01/2013
Name: Tropical Low
Identifier: 08U
Data At: 1800 UTC
Latitude: 19.6S
Longitude: 117.7E
Location Accuracy: within 25 nm [45 km]
Movement Towards: west northwest [289 deg]
Speed of Movement: 8 knots [16 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 998 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:
Dvorak Intensity Code:
Pressure of outermost isobar: 1004 hPa
Radius of outermost closed isobar: 70 nm [130 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 23/0600: 20.2S 116.6E: 050 [090]: 040 [075]: 992
+24: 23/1800: 20.9S 116.1E: 075 [135]: 030 [055]: 998
+36: 24/0600: 21.0S 115.7E: 095 [175]: 020 [035]: 1004
+48: 24/1800: 20.8S 115.0E: 115 [210]: 020 [035]: 1005
+60: 25/0600: 21.0S 113.6E: 130 [245]: 020 [035]: 1005
+72: 25/1800: 20.9S 112.2E: 150 [280]: 020 [035]: 1005
REMARKS:
Limited deep convection continues about this small system, mainly constrained to
the southern quadrants. Dvorak intensity provides ineffective guidance in this
instance - intensity is based on surface observations with Bedout Island and
Port Hedland airport recording winds in the 25 to 30 knot range.

Upper conditions remain moderately favourable this morning, however an
approaching upper trough combined with a strengthening ridge to the east of the
system is likely to lead to strengthening northerly shear during Wednesday.

ECMWF and GFS computer models have consistently forecast the top half of the
storm to rapidly separate due to this shear after 23 / 0600 UTC. The most recent
ECMWF run suggests that the low level centre may be dragged further southwards
over the Pilbara as the upper northerlies affect the system, before weakening
sufficiently for the shallow layer steering to push it westwards. This scenario
will bring useful rain further inland but will have little other effect.

Widespread 24 hour rainfall totals of 30 to 60 mm per day are expected with
isolated falls in the range 60-100mm and possible peak fall of around 150mm. The
heaviest rainfall is likely to occur within 50 kilometres of the coast but
localised heavy falls [even the peak fall] may occur further inland, especially
if the low tracks further inland.Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 23/0100 UTC by Perth TCWC.

[euro6208]

WTXS31 PGTW 230900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 12S (PETA) WARNING NR 003//
RMKS/
1. TROPICAL CYCLONE 12S (PETA) WARNING NR 003
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
230600Z --- NEAR 21.1S 117.6E
MOVEMENT PAST SIX HOURS - 185 DEGREES AT 09 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE AND RADAR
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 21.1S 117.6E
---
FORECASTS:
12 HRS, VALID AT:
231800Z --- 21.9S 116.8E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 260 DEG/ 03 KTS
---
24 HRS, VALID AT:
240600Z --- 22.0S 116.1E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 36 HR POSIT: 265 DEG/ 05 KTS
---
36 HRS, VALID AT:
241800Z --- 22.1S 115.1E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 48 HR POSIT: 270 DEG/ 06 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
250600Z --- 22.1S 113.7E
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 72 HR POSIT: 275 DEG/ 08 KTS
---
72 HRS, VALID AT:
260600Z --- 21.8S 110.2E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
230900Z POSITION NEAR 21.3S 117.4E.
TROPICAL CYCLONE (TC) 12S (PETA), LOCATED APPROXIMATELY 210 NM EAST-
NORTHEAST OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTHWARD AT 09 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS A SYMMETRIC SYSTEM WITH IMPROVED CONVECTIVE BANDING WITH A
CENTRAL DENSE OVERCAST FEATURE THAT CONTINUES TO OBSCURE THE LLCC.
THE DAMPIER AUSTRALIA RADAR SHOWS A DEFINED CENTER WITH TIGHTLY-
CURVED CONVECTIVE BANDING OVER THE SOUTHERN SEMI-CIRCLE. OVER THE
PAST SIX HOURS, TC 12S HAS TRACKED ERRATICALLY AND HAS RECENTLY MADE
A SHARP TURN TO THE SOUTH, MOVING OVERLAND. UPPER-LEVEL ANALYSIS
INDICATES THAT THE LLCC IS LOCATED UNDER THE SUBTROPICAL RIDGE AXIS
WITH WEAK VERTICAL WIND SHEAR (10 TO 15 KNOTS) AND GOOD POLEWARD
OUTFLOW, WHICH IS BEING ENHANCED BY THE NORTHWESTERLY FLOW OVER
WESTERN AUSTRALIA. THE INITIAL INTENSITY IS ASSESSED AT 35 KNOTS
BASED ON OBSERVATIONS IN THE AREA AND PERSISTENCE AS DVORAK
INTENSITY ESTIMATES WERE BEGINNING TO CLIMB PRIOR TO LANDFALL. THERE
IS HIGH CONFIDENCE IN THE INITIAL POSITION BASED ON THE RADAR
IMAGERY. TC 12S IS FORECAST TO TURN SOUTHWESTWARD AS THE LOW-LEVEL
STEERING RIDGE WEAKENS IN RESPONSE TO AN APPROACHING MIDLATITUDE
SHORTWAVE TROUGH THROUGH TAU 12. AFTER TROUGH PASSAGE, THE LOW-LEVEL
STEERING RIDGE IS FORECAST TO BUILD WEST OF AUSTRALIA PROVIDING A
WESTWARD STEERING INFLUENCE. TC 12S IS FORECAST TO MAINTAIN 35 KNOTS
THROUGH TAU 48 AS IT TRACKS ALONG THE COAST AND THEN DISSIPATE AS IT
TRACKS INTO THE INDIAN OCEAN WITH COOL SSTS (24 TO 26C) AND
INCREASING VWS. THERE IS A POSSIBILITY THAT THE SYSTEM COULD
DISSIPATE SOONER THEN TAU 72 DUE TO THE LAND INTERACTION. DYNAMIC
MODEL GUIDANCE IS IN GOOD AGREEMENT, THEREFORE, THERE IS HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK. NEXT WARNINGS AT 231500Z,
232100, 240300Z AND 240900Z.//
NNNN

[Hurricane_Luis]

Tropical Cyclone Peta

[Hurricane_Luis]

It lives...It lives!