Posted 08 May 2012 - 05:55 AM
Whilst the season may have officially ended a low pressure system has been developing to the north of Australia. An earlier report from JTWC:
THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 5.0S
126.8E, IS NOW LOCATED NEAR 4.5S 126.2E, APPROXIMATELY 545 NM NORTH-
NORTHWEST OF DARWIN, AUSTRALIA. ANIMATED INFRARED SATELLITE IMAGERY
SHOWS PERSISTENT CENTRAL CONVECTION WITH DEEP BANDING OVER THE
WESTERN SEMI-CIRCLE OF THE LOW-LEVEL CIRCULATION CENTER (LLCC). A
051259Z AMSU IMAGE DEPICTS THE DEEP BANDING WRAPPING INTO THE LLCC
FROM THE WEST WITH MUCH WEAKER AND FRAGMENTED BANDS FEEDING IN FROM
THE EAST. A RECENT SHIP OBSERVATION IN THE AREA INDICATES 1006 MB
AND 25 KNOTS. THE 051200Z PGTW UPPER-LEVEL ANALYSIS SHOWS A POINT
SOURCE OF DIFFLUENCE APPROXIMATELY 5 DEGREES TO THE EAST OF THE
LLCC. THIS IS PROVIDING FOR GOOD OUTFLOW IN BOTH THE EQUATORWARD
AND POLEWARD DIRECTIONS AND KEEPING VERTICAL WIND SHEAR LIGHT (05-
10 KNOTS). SEA SURFACE TEMPERATURES IN THE AREA ARE ABOVE 30
DEGREES CELSIUS, HIGHLY CONDUCIVE FOR TROPICAL CYCLONE DEVELOPMENT.
NUMERICAL MODEL GUIDANCE INDICATES INTENSITY DEVELOPMENT TO REACH
WARNING CRITERIA (35 KNOTS) WITHIN THE 36-48 HOUR TIMEFRAME.
HOWEVER, DUE TO THE FAVORABLE UPPER- AND LOWER-LEVEL ENVIRONMENTS,
THAT TIMEFRAME MAY BECOME ACCELERATED AS THE NEXT MODEL RUNS COME
IN. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 22 TO 27
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM
Monday (7th May) it had developed into a weak tropical cyclone:
071500Z POSITION NEAR 8.3S 129.8E.
TROPICAL CYCLONE (TC) 19S, LOCATED APPROXIMATELY 270 NM NORTH-
NORTHWEST OF DARWIN, AUSTRALIA, HAS TRACKED SOUTH-SOUTHEASTWARD AT
13 KNOTS DURING THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE
IMAGERY SHOWS TC 19S HAS WEAKENED SIGNIFICANTLY IN THE PAST 12 HOURS
AND NOW HAS MINIMAL ASSOCIATED DEEP CONVECTION. ADDITIONALLY, A
071110Z SSMIS DEPICTS A VERY WEAK, FULLY EXPOSED LOW LEVEL
CIRCULATION CENTER, FROM WHICH THE INITIAL POSITION WAS BASED. THE
INITIAL INTENSITY WAS ON THE LOWER SIDE OF THE KNES AND PGTW 25 TO
35 KNOT DVORAK ESTIMATES BECAUSE OF THE WEAK CONVECTIVE SIGNATURE IN
MICROWAVE IMAGERY. TC 19S IS EXPECTED TO CONTINUE TO WEAKEN UNDER
HIGH VERTICAL WIND SHEAR, BUT COULD POTENTIALLY REDEVELOP AS IT
TRACKS UNDER THE SUBTROPICAL RIDGE AXIS TO THE SOUTH. THIS IS THE
FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WARNING CENTER.
THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 071200Z IS 10 FEET.//
Tuesday (today) it had weakened below TC strength but JTWC still give it a possibility of re-intensifying.
ABIO10 PGTW 081230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN
B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION (REMNANTS OF TC 19S) HAS PERSISTED
NEAR 9.1S 129.2E, APPROXIMATELY 220 NM NORTH-NORTHWEST OF DARWIN,
AUSTRALIA. ANIMATED INFRARED SATELLITE IMAGERY REVEALS FLARING
CONVECTION OVER THE PAST 12 HOURS, WITH AN EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC) OBSERVED BETWEEN CONVECTIVE CYCLES. A
080715Z SSMI IMAGE DEPICTS FRAGMENTED WEAK BANDING, WITH THE DEEPEST
CONVECTION ALONG THE SOUTHERN PERIPHERY OF THE LLCC. A 080316Z OSCAT
PASS SHOWS AN ELONGATED AREA OF SHARP TROUGHING STRETCHING ALONG THE
8S LATITUDE LINE, WITH MAXIMUM WIND SPEEDS OF 30-35 KNOTS NEAR 129E
LONGITUDE. UPPER LEVEL ANALYSIS INDICATES THIS AREA IS JUST
EQUATORWARD OF A NEAR EQUATORIAL RIDGE AXIS, WITH APPROXIMATELY 15-
20 KTS OF VERTICAL WIND SHEAR (VWS). AS THE RECENT MOVEMENT HAS HAD
A MORE SOUTHERLY COMPONENT (TOWARDS THE RIDGE AXIS), THE VWS HAS
RELAXED SLIGHTLY AND MAY CONTINUE TO DO SO IF THIS MOTION PERSISTS.
NUMERICAL MODEL GUIDANCE SUGGESTS THAT REGENERATION OF TC 19S IS
POSSIBLE, PARTICULARLY IF THE SOUTHWARD MOTION CONTINUES. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002 MB. DUE TO THE CURRENT
MOTION AND RELAXING SHEAR, THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS MEDIUM.
However, it's moving more westwards and the Bureau of Meteorology gives the possibility of TC formation in the Northern Region (Darwin) as low:
Australian Government Bureau of Meteorology, Northern Territory, Darwin Regional Forecasting Centre
Tropical Cyclone 3 day Outlook for Northern Region, including the Gulf of Carpentaria
Issued by the BUREAU OF METEOROLOGY, DARWIN
at 2:20 pm CST Tuesday 8 May 2012
Valid until the end of Friday.
Existing Cyclones in the Northern Region and Gulf of Carpentaria:
A Tropical Low, 1002 hPa, is located in the Banda Sea, near 7.8S 129.2E, about 400 kilometres east northeast of Dili. The low is expected to move slowly southwest on Wednesday and Thursday, close to or over the island of Timor, then move steadily west later in the week. There is a possibility that the low could take a more southward track into the northern Timor Sea before turning west, away from the northern region. If the low takes a more southward track, the risk of tropical cyclone development late Wednesday or early Thursday would increase slightly.
Likelihood of a tropical cyclone being in the Northern Region on:
Friday: very low.