SIO: 12R - Tropical Disturbance (15S)

[HURAKAN]

ECMWF predicts this system to move generally west



GFS expects the system to move further southwest

[Crostorm]

B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION HAS PERSISTED NEAR 12.7S 75.7E,
APPROXIMATELY 375 NM SOUTH-SOUTHEAST OF DIEGO GARCIA. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY SHOWS AN ELONGATED LOW LEVEL
CIRCULATION CENTER (LLCC) STARTING TO CONSOLIDATE INTO A MORE
SYMMETRICALLY ORGANIZED CIRCULATION. CONVECTION HAS BEEN SPORADIC
AND IS CURRENTLY BEING SHEARED WESTWARD. SEA SURFACE TEMPERATURES
ARE FAVORABLE IN THE REGIONS (29 TO 31 DEGREES CELSIUS). UPPER LEVEL
ANALYSIS INDICATES A BUILDING ANTICYCLONE TO THE SOUTH OF THE LLCC
IS CREATING SIGNIFICANT VERTICAL WIND SHEAR (VWS) (30 PLUS KNOTS)
OVER THE AREA, HINDERING CONVECTION FROM BUILDING. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1008 MB. BASED ON THE STRONG VWS
AND ELONGATION OF THE LLCC, THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.

[Crostorm]

Animation Ecmwf 00

[Crostorm]

(1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 12.7S
75.7E, IS NOW LOCATED NEAR 11.0S 74.4E, APPROXIMATELY 250 NM SOUTH-
SOUTHEAST OF DIEGO GARCIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
SHOWS AN ELONGATED LOW LEVEL CIRCULATION CENTER (LLCC) WITH
PERSISTENT DEEP CONVECTION. A 241548Z SSMIS IMAGE INDICATES WEAK,
FORMATIVE BANDING OVER THE SOUTHERN SEMI-CIRCLE. A 240455Z ASCAT
IMAGE DEPICTS ELONGATED TROUGHING WITH NO EVIDENCE OF A DEFINED
LLCC. UPPER LEVEL ANALYSIS INDICATES THAT THE LLCC IS LOCATED
NORTHEAST OF AN ANTICYCLONE AND IS UNDER MODERATE TO STRONG (20-30
KNOTS) EASTERLY VERTICAL WIND SHEAR. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

[Crostorm]

No more 90S on NRL

[Crostorm]

Its back

[Crostorm]

(1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 11.0S
74.4E, HAS DISSIPATED AND IS NO LONGER SUSPECT FOR THE DEVELOPMENT
OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS.

[Crostorm]

(2) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 11.4S
69.9E, IS NOW LOCATED NEAR 11.6S 69.4E, APPROXIMATELY 310 NM
SOUTHWEST OF DIEGO GARCIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
SHOWS A TIGHTLY ORGANIZED LOW LEVEL CIRCULATION CENTER (LLCC) WITH
ACTIVE CONVECTIVE BANDS OVER BOTH SEMICIRCLES. A 280514Z ASCAT PASS
CONFIRMS THE EXISTENCE OF 20 TO 25 KNOT WINDS IN ALL QUADRANTS
AROUND A SYMMETRICAL LOW LEVEL CIRCULATION CENTER. THE 281200Z PGTW
UPPER LEVEL STREAMLINE ANALYSIS REVEALS A VIGOROUS UPPER LEVEL
ANTICYCLONE EAST OF MADAGASCAR. THE ANTICYCLONE HAS BEEN STEADY AND
STATIONARY OVER THE PAST 72 HOURS AND HAS BEEN GENERATING
SUBSIDENCE OVER THE SOUTHWEST QUADRANT. ANIMATED WATER VAPOR
IMAGERY DEPICTS A COMPLEX UPPER LEVEL PATTERN, WITH A DEVELOPING
POLEWARD CHANNEL OVER THE SOUTHEAST QUADRANT AND VIGOROUS
EQUATORWARD OUTFLOW, BUT STRONG SUBSIDENCE OVER THE SOUTHWESTERN
QUADRANT. CURRENTLY, VERTICAL WIND SHEAR IS APPROXIMATELY 20 KNOTS
BUT THE LLCC IS SHOWING SIGNS OF SOUTHEASTWARD MOVEMENT, WHICH WILL
CARRY IT INTO A REGION OF LIGHTER SHEAR. 28 DEGREE SEA SURFACE
TEMPERATURES IN THE REGION ARE SUPPORTIVE OF DEVELOPMENT. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 22 TO 28 KNOTS. MINIMUM
SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002 MB. THE POTENTIAL
FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE
NEXT 24 HOURS IS UPGRADED TO MEDIUM.

[Chacor]

Tropical Disturbance 12R.

WTIO30 FMEE 290111
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 1/12/20112012
1.A TROPICAL DISTURBANCE 12
2.A POSITION 2012/02/29 AT 0000 UTC:
WITHIN 20 NM RADIUS OF POINT 12.5 S / 69.2 E
(TWELVE DECIMAL FIVE DEGREES SOUTH AND SIXTY NINE DECIMAL TWO DEGREES EAST)
MOVEMENT : SOUTH 3 KT
3.A DVORAK ANALYSIS: 2.0/2.0/D 0.5/12 H
4.A CENTRAL PRESSURE: 999 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 25 KT
RADIUS OF MAXIMUM WINDS (RMW) :NIL
6.A EXTENSION OF WIND BY QUADRANTS (KM):
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1004 HPA / 900 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM
1.B FORECASTS:
12H: 2012/02/29 12 UTC: 13.3 S / 69.1 E, MAX WIND=030 KT, TROPICAL DEPRESSION
24H: 2012/03/01 00 UTC: 14.5 S / 68.2 E, MAX WIND=030 KT, TROPICAL DEPRESSION
36H: 2012/03/01 12 UTC: 15.5 S / 67.8 E, MAX WIND=030 KT, TROPICAL DEPRESSION
48H: 2012/03/02 00 UTC: 16.6 S / 67.7 E, MAX WIND=030 KT, TROPICAL DEPRESSION
60H: 2012/03/02 12 UTC: 17.9 S / 67.5 E, MAX WIND=030 KT, TROPICAL DEPRESSION
72H: 2012/03/03 00 UTC: 19.0 S / 68.8 E, MAX WIND=035 KT, MODERATE TROPICAL STORM
2.B LONGER-RANGE OUTLOOK :
96H: 2012/03/04 00 UTC: 22.9 S / 68.2 E, MAX WIND=035 KT, MODERATE TROPICAL STORM
120H: 2012/03/05 00 UTC: 24.3 S / 68.8 E, MAX WIND=035 KT, MODERATE TROPICAL STORM
2.C ADDITIONAL INFORMATIONS:
T AND CI=2.0
SINCE 1800Z, DEEP CONVECTIVE ACTIVITY HAS CONSOLIDATED NEAR THE CENTRE AND ORGANIZED ON A CURVED B
AND PATTERN.
SSMI F15 28/2310Z CONFIRMS THIS BETTER FEATURE.
LOW LEVEL INFLOW IMPROVES ON THE BOTH SIDES AND EASTERLY VERTICAL WINDSHEAR HAS TEMPORARILY WEAKEN
ED BUT IS FORECAST TO ENFORCE BACK TODAY LATE AND TOMORROW THURSDAY.
NWP MODELS ARE NOW IN GOOD AGREEMENT TO FORECAST A GLOBALLY SOUTHWARDS MOTION.
OVER THIS EXPECTED TRACK, ENVIRONMENTAL CONDITIONS SHOULD BECOME FAVOURABLE ON FRIDAY UNDER THE UP
PER LEVEL RIDGE BUT A NEW NORTHERLY VERTICAL WINDSHEAR CONSTRAINT SHOULD ESTABLISHED ON AND AFTER
SATURDAY.
POTENTIAL FOR INTENSIFICATION IS THEREFORE LIMITED AT SHORT OR MEDIUM RANGE.

[HURAKAN]

Much better organized

[HURAKAN]

Latest visible, likely to be upgraded soon if it keeps improving

[HURAKAN]

WTIO30 FMEE 290645
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 2/12/20112012
1.A TROPICAL DEPRESSION 12
2.A POSITION 2012/02/29 AT 0600 UTC:
WITHIN 20 NM RADIUS OF POINT 12.6 S / 68.4 E
(TWELVE DECIMAL SIX DEGREES SOUTH AND SIXTY EIGHT DECIMAL FOUR
DEGREES EAST)
MOVEMENT : WEST-SOUTH-WEST 6 KT
3.A DVORAK ANALYSIS: 2.5/2.5/D 1.0/24 H
4.A CENTRAL PRESSURE: 997 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 30 KT
RADIUS OF MAXIMUM WINDS (RMW) :NIL
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 70 SE: 110 SW: 110 NW: 70
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1005 HPA / 900 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM
1.B FORECASTS:
12H: 2012/02/29 18 UTC: 13.3 S / 67.5 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
24H: 2012/03/01 06 UTC: 14.3 S / 66.1 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
36H: 2012/03/01 18 UTC: 15.6 S / 64.7 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
48H: 2012/03/02 06 UTC: 16.7 S / 64.0 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
60H: 2012/03/02 18 UTC: 17.7 S / 63.9 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
72H: 2012/03/03 06 UTC: 18.7 S / 64.5 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
2.B LONGER-RANGE OUTLOOK :
96H: 2012/03/04 06 UTC: 21.7 S / 66.3 E, MAX WIND=030 KT, TROPICAL DEPRESSION
120H: 2012/03/05 06 UTC: 23.3 S / 64.9 E, MAX WIND=030 KT, TROPICAL DEPRESSION
2.C ADDITIONAL INFORMATIONS:
T AND CI=2.5 THE CLOUD PATTERN IS NOW A COLD CLOUDS TOP CDO. LATEST BURST OF
CONVECTION HAS STARTED AT 0300Z. MW IMAGERY REVEAL A RATHER SMALL
CORE SYSTEM AND IT IS POSSIBLE THAT THE SYSTEM MAY HAVE ALREADY
REACHED THE MODERATE TROPICAL STORM LEVEL.
LOW LEVEL INFLOW IMPROVES ON THE BOTH SIDES. THE UPPER LEVEL TROUGH
LOCATED YESTERDAY CLOSED TO THE SOUTHWEST OF THE SYSTEM IS NOW
MOVING AWAYS ALLOWING AN IMPROVEMENT OF THE UPPER LEVEL DIVERGENCE
AS SEEN WITH THE IMPRESSIVE OUTFLOW PATTERN (MORE LIMITED IN THE
EASTERN SECTOR HOWEVER).
THE SYSTEM SHOULD BE TO THE NORTH OF THE UPPER LEVEL RIDGE UNTIL
THURSDAY NIGHT AND EXPERIENCING SOME EASTERLY SHEAR. SO
INTENSIFICATION SHOULD BE RATHER LIMITED UNTIL THAT TIME. FRIDAY,
ENVIRONMENTAL CONDITIONS SHOULD BECOME FAVOURABLE UNDER THE UPPER
LEVEL RIDGE BUT A NEW NORTHERLY VERTICAL WINDSHEAR CONSTRAINT
SHOULD ESTABLISHED ON AND AFTER SATURDAY. OVERALL, THE POTENTIAL OF
INTENSIFICATION APPEARS RATHER LOW ... HOWEVER GIVEN THE SMALL SIZE OF
THE INNER CORE, SOME STRONGER VARIATIONS IN INTENSITY THAN PRESENTLY
INDICATED COULD BE OBSERVED.
THE TRACK FORECAST IS SIGNIFICANTLY ADJUSTED TO THE WEST BASED ON FIRST
00Z GUIDANCES OUTPUT. THE SYSTEM SHOULD ROUND THE SUBTROPICAL HIGHS
LOCATED TO ITS EAST AND SHOULD BE FRIDAY NIGHT AHEAD OF A NEW UPPER TO
MID LEVEL TROUGH. THE TRACK COULD TAKE BY THAT TIME A SOUTHESATWARDS
MOTION. AT THE END OF THE FORECAST, A WEAKENING SYSTEM SHOULD TRACK
WESTWARDS WITHIN A LOW LEVEL STEERING FLOW.
INHABITANTS OF RODRIGUES ISLAND SHOULD START TO MONITOR THE PROGRESS
OF THIS SYSTEM.

[HURAKAN]

latest visible

[HURAKAN]

WTXS21 PGTW 290800
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 12.3S 68.8E TO 16.4S 65.7E WITHIN
THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF
NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA
ARE ESTIMATED TO BE 28 TO 32 KNOTS. METSAT IMAGERY AT 290530Z
INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 12.9S 68.6E.
THE SYSTEM IS MOVING WEST-SOUTHWESTWARD AT 07 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 11.6S
69.4E, IS NOW LOCATED NEAR 12.9S 68.6E, APPROXIMATELY 400 NM
SOUTHWEST OF DIEGO GARCIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
SHOWS A TIGHTLY ORGANIZED LOW LEVEL CIRCULATION CENTER (LLCC) WITH
ACTIVE CONVECTIVE BANDS OVER BOTH SEMICIRCLES. A 290452Z METOP-A
MICROWAVE PASS SUPPORTS THE WELL DEFINED LLCC WITH DEEP CENTRAL
CONVECTION BUILDING. UPPER LEVEL ANALYSIS INDICATES A MID-LATITUDE
TROUGH HAS STARTED TO MOVE TO THE SOUTHEAST OF THE LLCC , HELPING TO
ENHANCE THE STRONG POLEWARD OUTFLOW OBSERVED IN ANIMATED WATER VAPOR
IMAGERY OVER THE PAST 12 HOURS. THE LLCC HAS BEEN SLOWLY TRACKING
TOWARDS THE AXIS OF AN UPPER LEVEL SUBTROPICAL RIDGE AND INTO AN
AREA OF WEAKER VERTICAL WIND SHEAR (LESS THAN 10 KNOTS). SEA SURFACE
TEMPERATURES ARE BETWEEN 29 AND 30 DEGREES CELSIUS, SUPPORTING THE
RECENT DEVELOPMENT AND FURTHER DEVELOPMENT OVER THE NEXT 24 HOURS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 32 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
010800Z.//
NNNN

[HURAKAN]

Latest track

[HURAKAN]

WTIO30 FMEE 291214
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 3/12/20112012
1.A TROPICAL DEPRESSION 12
2.A POSITION 2012/02/29 AT 1200 UTC:
WITHIN 20 NM RADIUS OF POINT 13.5 S / 67.8 E
(THIRTEEN DECIMAL FIVE DEGREES SOUTH AND SIXTY SEVEN DECIMAL EIGHT
DEGREES EAST)
MOVEMENT : SOUTH-WEST 9 KT
3.A DVORAK ANALYSIS: 2.5/2.5/D 1.0/24 H
4.A CENTRAL PRESSURE: 997 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 30 KT
RADIUS OF MAXIMUM WINDS (RMW) :NIL
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 70 SE: 220 SW: 280 NW: 70
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1003 HPA / 600 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM
1.B FORECASTS:
12H: 2012/03/01 00 UTC: 14.2 S / 66.9 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
24H: 2012/03/01 12 UTC: 15.2 S / 65.9 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM
36H: 2012/03/02 00 UTC: 16.5 S / 65.3 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
48H: 2012/03/02 12 UTC: 17.7 S / 65.4 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
60H: 2012/03/03 00 UTC: 19.3 S / 65.9 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
72H: 2012/03/03 12 UTC: 20.9 S / 66.7 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
2.B LONGER-RANGE OUTLOOK :
96H: 2012/03/04 12 UTC: 24.2 S / 67.2 E, MAX WIND=040 KT, EXTRATROPICAL SYSTEM
120H: 2012/03/05 12 UTC: 24.1 S / 64.3 E, MAX WIND=035 KT, EXTRATROPICAL SYSTEM
2.C ADDITIONAL INFORMATIONS:
T AND CI=2.5 THE CLOUD PATTERN HAS NOT SIGNIFICANTLY IMPROVED DURING THE LAST 6
HOURS. IT IS STILL AN IRREGULAR CDO LESS THAN 90 NM IN DIAMETER ON VIS
0924Z N19 IMAGERY. SOME SIGNIFICANT FLUCTUTATIONS IN SIZE AND SHAPE OF
THIS CDO APPEAR ASSOCIATED TO THE OCCURENCE OF CONVECTIVE BURST. THE
SYSTEM REMAINS A SMALL SIZE INNER-CORE SYSTEM.
LOW LEVEL INFLOW IMPROVES ON THE BOTH SIDES. THE UPPER LEVEL
DIVERGENCE REMAINS IMPRESSIVE AND SEEMS TO IMPROVE OVER THE EASTERN
SIDE ACCORDING TO LATEST SAT PICS.
THE SYSTEM TRACKS NOW SOUTHWESTWARDS AND IS GETTING CLOSER OF THE
UPPER LEVEL RIDGE. ALTHOUGHT SOME EASTERLY SHEAR COULD REMAIN
TOMORROW, IT APPEARS LIKELY THAT THE SYSTEM WILL GAIN A LITTLE BIT OF
STRENGTH. FRIDAY, ENVIRONMENTAL CONDITIONS SHOULD BE AT ITS BEST UNDER
THE UPPER LEVEL RIDGE ... PRESENT INTENSITY FORECAST IS RATHER LOW GIVEN
THAT FEW OR NONE OF THE GUIDANCE STRENGHEN SIGNIFICANTLY THE SYSTEM
UNTIL FRIDAY ... HOWEVER GIVEN THE SMALL SIZE OF THE INNER CORE, ONE
COULD NOTE THAT SOME STRONGER VARIATIONS IN INTENSITY THAN PRESENTLY
INDICATED COULD BE OBSERVED.
FROM SATURDAY TO THE END OF THE FORECAST PERIOD, A NEW NORTHERLY
VERTICAL WINDSHEAR CONSTRAINT SHOULD ESTABLISHED. HOWEVER MOST OF
THE GUIDANCE DEEPEN THE SYSTEM BY THAT TIME. FURTHER ANALYSIS SHOW
THAT THIS INTENSIFICATION MAY COME FROM BAROCLINIC PROCESS ...
CONSEQUENTLY, EN EXTRATROPICAL TRANSITION MAY BEGIN SUNDAY.
THE SYSTEM SHOULD ROUND THE SUBTROPICAL HIGHS LOCATED TO ITS EAST AND
SHOULD BE FRIDAY NIGHT AHEAD OF A NEW UPPER TO MID LEVEL TROUGH. THE
TRACK COULD TAKE BY THAT TIME A SOUTHEEASTWARDS MOTION BETWEEN THE
TROUGH LOCATED TO ITS SOUTHWEST AND THE SUBTROPICAL RIDGE TO ITS
NORTHEAST . AFTER THAT, THE PREDILECTED SCENARIO IS WESTWARDS TURN ON
THE NORTHERN SIDE OF THE SUBTROPICAL RIDGE. ECMWF ENSEMBLE FORECAST
SHOW SOME SIGNIFICANT SPREAD AROUND THIS "S" TRACK.
IF THE PRESENT TRACK FORECAST A LOWER THREAT FOR RODRIGUES,
INHABITANTS OF RODRIGUES ISLAND SHOULD MONITOR THE PROGRESS OF THIS
SYSTEM, AS A MORE SERIOUS THREAT COULD NOT BE RULED OUT DURING THE
NEXT FEW DAYS ...

[HURAKAN]

Next name is Joni

[HURAKAN]

WTIO30 FMEE 291851
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 4/12/20112012
1.A TROPICAL DEPRESSION 12
2.A POSITION 2012/02/29 AT 1800 UTC:
WITHIN 30 NM RADIUS OF POINT 13.9 S / 67.6 E
(THIRTEEN DECIMAL NINE DEGREES SOUTH AND SIXTY SEVEN DECIMAL SIX
DEGREES EAST)
MOVEMENT : SOUTH 7 KT
3.A DVORAK ANALYSIS: 2.5/2.5/D 0.5/24 H
4.A CENTRAL PRESSURE: 996 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 30 KT
RADIUS OF MAXIMUM WINDS (RMW) :NIL
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 70 SE: 220 SW: 280 NW: 70
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1003 HPA / 600 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP
1.B FORECASTS:
12H: 2012/03/01 06 UTC: 14.8 S / 66.5 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
24H: 2012/03/01 18 UTC: 15.7 S / 65.2 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM
36H: 2012/03/02 06 UTC: 16.4 S / 64.3 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
48H: 2012/03/02 18 UTC: 17.6 S / 64.3 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
60H: 2012/03/03 06 UTC: 18.9 S / 65.2 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
72H: 2012/03/03 18 UTC: 20.4 S / 66.5 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
2.B LONGER-RANGE OUTLOOK :
96H: 2012/03/04 18 UTC: 24.2 S / 66.7 E, MAX WIND=040 KT, EXTRATROPICAL SYSTEM
120H: 2012/03/05 18 UTC: 24.5 S / 62.2 E, MAX WIND=035 KT, EXTRATROPICAL SYSTEM
2.C ADDITIONAL INFORMATIONS:
T = 2.5- AND CI=2.5 THE CLOUD PATTERN IS STILL AN IRREGULAR CDO. SOME SIGNIFICANT
FLUCTUTATIONS IN SIZE AND SHAPE OF THIS CDO APPEAR ASSOCIATED TO THE
OCCURENCE OF CONVECTIVE BURST, AND SEEMS UNDERGOING A LITTLE
EASTERLY UPPER LEVEL CONSTRAINT . THE SYSTEM REMAINS A SMALL SIZE
INNER-CORE SYSTEM.
LOW LEVEL INFLOW IMPROVES ON THE BOTH SIDES. THE UPPER LEVEL
DIVERGENCE REMAINS IMPRESSIVE BUT ALWAYS QUITE LIMITATED OVER THE
EASTERN SIDE.
THE SYSTEM TRACKS NOW SOUTH SOUTHWESTWARDS AND IS GETTING CLOSER OF
THE UPPER LEVEL RIDGE. ALTHOUGHT SOME EASTERLY SHEAR COULD REMAIN
TOMORROW, IT APPEARS LIKELY THAT THE SYSTEM WILL GAIN A LITTLE BIT OF
STRENGTH. FRIDAY, ENVIRONMENTAL CONDITIONS SHOULD BE AT ITS BEST UNDER
THE UPPER LEVEL RIDGE ... PRESENT INTENSITY FORECAST IS RATHER LOW GIVEN
THAT FEW OR NONE OF THE GUIDANCE STRENGHEN SIGNIFICANTLY THE SYSTEM
UNTIL FRIDAY ... HOWEVER GIVEN THE SMALL SIZE OF THE INNER CORE, ONE
COULD NOTE THAT SOME STRONGER VARIATIONS IN INTENSITY THAN PRESENTLY
INDICATED COULD BE OBSERVED.
FROM SATURDAY TO THE END OF THE FORECAST PERIOD, A NEW NORTHERLY
VERTICAL WINDSHEAR CONSTRAINT SHOULD ESTABLISHED. HOWEVER MOST OF
THE GUIDANCE DEEPEN THE SYSTEM BY THAT TIME. FURTHER ANALYSIS SHOW
THAT THIS INTENSIFICATION MAY COME FROM BAROCLINIC PROCESS ...
CONSEQUENTLY, EN EXTRATROPICAL TRANSITION MAY BEGIN SUNDAY.
THE SYSTEM SHOULD ROUND THE SUBTROPICAL HIGHS LOCATED TO ITS EAST AND
SHOULD BE FRIDAY NIGHT AHEAD OF A NEW UPPER TO MID LEVEL TROUGH. THE
TRACK COULD TAKE BY THAT TIME A SOUTHEEASTWARDS MOTION BETWEEN THE
TROUGH LOCATED TO ITS SOUTHWEST AND THE SUBTROPICAL RIDGE TO ITS
NORTHEAST . AFTER THAT, THE PREDILECTED SCENARIO IS WESTWARDS TURN ON
THE NORTHERN SIDE OF THE SUBTROPICAL RIDGE. ECMWF ENSEMBLE FORECAST
SHOW SOME SIGNIFICANT SPREAD AROUND THIS "S" TRACK.
INHABITANTS OF RODRIGUES ISLAND SHOULD MONITOR THE PROGRESS OF THIS
SYSTEM, AS A MORE SERIOUS THREAT COULD NOT BE RULED OUT DURING THE
NEXT FEW DAYS ...

[HURAKAN]

NRL says 15S

[HURAKAN]

WTXS32 PGTW 292100
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 15S (FIFTEEN) WARNING NR 001//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/290751Z FEB 12//
AMPN/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. TROPICAL CYCLONE 15S (FIFTEEN) WARNING NR 001
02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
291800Z --- NEAR 13.8S 67.3E
MOVEMENT PAST SIX HOURS - 240 DEGREES AT 08 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: 13.8S 67.3E
---
FORECASTS:
12 HRS, VALID AT:
010600Z --- 14.5S 66.0E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 235 DEG/ 07 KTS
---
24 HRS, VALID AT:
011800Z --- 15.3S 64.8E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 220 DEG/ 05 KTS
---
36 HRS, VALID AT:
020600Z --- 16.1S 64.1E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 195 DEG/ 04 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
021800Z --- 16.9S 63.9E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 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
060 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 160 DEG/ 07 KTS
---
72 HRS, VALID AT:
031800Z --- 19.7S 65.0E
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: 190 DEG/ 06 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
041800Z --- 22.2S 64.5E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
292100Z POSITION NEAR 14.0S 67.0E.
TROPICAL CYCLONE (TC) 15S (FIFTEEN), LOCATED APPROXIMATELY 490 NM
SOUTHWEST OF DIEGO GARCIA, HAS TRACKED WEST-SOUTHWESTWARD AT 08
KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY
AND A 291725Z AMSU MICROWAVE IMAGE SHOW INCREASED DEEP CONVECTION
TIGHTLY WRAPPING INTO A WELL-DEFINED LOW LEVEL CIRCULATION CENTER
(LLCC), FROM WHICH THE INITIAL POSITION WAS BASED. THE INITIAL
INTENSITY WAS BASED ON PGTW, KNES, AND FMEE DVORAK ESTIMATES RANGING
FROM 30 TO 35 KNOTS. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS
LOCATED DIRECTLY UNDER THE RIDGE AXIS IN AN AREA OF LOW VERTICAL
WIND SHEAR. AN UPPER LEVEL TROUGH TO THE WEST IS INCREASING OUTFLOW.
TC 15S IS CURRENTLY TRACKING ALONG THE NORTHWESTERN PERIPHERY OF A
LOW- TO MID-LEVEL STEERING RIDGE. AFTER TAU 36, THE SYSTEM IS
EXPECTED TO TURN POLEWARD WHEN AN UPPER LEVEL TROUGH WEAKENS THE
STEERING RIDGE. TC 15S SHOULD SIGNIFICANTLY WEAKEN BY TAU 72, DUE TO
INCREASED VERTICAL WIND SHEAR ASSOCIATED WITH AN APPROACHING UPPER
LEVEL TROUGH. TC 15S WILL BEGIN TO TURN SOUTHWESTWARD AS THE LOW
LEVEL STEERING RIDGE REBUILDS IN TO THE SOUTH. THE SYSTEM WILL
DISSIPATE AS A SIGNIFICANT TROPICAL CYCLONE BY TAU 96. NUMERICAL
MODEL GUIDANCE SUPPORTS THE POLEWARD TURN AND DISSIPATION SCENARIO.
HOWEVER, SEVERAL MODELS INCLUDING GFDN, WBAR, AND EGRR EXTEND
FARTHER WESTWARD BEFORE TURNING POLEWARD IN THE EARLY TAUS. THIS
FORECAST IS IN AGREEMENT WITH ECMWF, NOGAPS, AND GFS. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 291800Z IS 8 FEET. NEXT WARNINGS AT
010900Z AND 012100Z. THIS WARNING SUPERSEDES AND CANCELS REF A,
JOINT TYPHOON WRNCEN 290751Z FEB 12 TROPICAL CYCLONE FORMATION ALERT
(WTXS21 PGTW 290800). REFER TO TROPICAL CYCLONE 14S (IRINA) WARNINGS
(WTXS31 PGTW) FOR TWELVE-HOURLY UPDATES.//
NNNN