SIO: IRINA - Post-Tropical

[HURAKAN]

Latest

[HURAKAN]

becoming better organized

[Crostorm]

[Crostorm]

[Crostorm]

AWIO20 FMEE 251214
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER IN
THE SOUTHWEST INDIAN OCEAN
DATE: 2012/02/25 AT 1200 UTC
PART 1:
WARNING SUMMARY:
Nil.
PART 2 :
TROPICAL WEATHER DISCUSSION:
Transequatorial monsoon flow is established from the African coasts to 75E. Trade wind flow is
rather pronounced south of 14S and East of 70E.
Monsoon trough is pronounced along 13S/58E - 12S/65E - 11S/75E - 12S/88E.
Convective activity within the ITCZ is moderate to important within the monsoon trough
particularly within three distinct areas :
- between 50E and 60E, where convection has developed at the end of the last night, but last data
MW (TRMM of 0536Z) does not show any organisation or clear clockwise circulation. however a
low seems to develop near 12.6S/55.6E as pressions have clearly decreased on this area during the
next 24 hours ( -2hPa on Tromelin, -3.9hPa on Algalega), MSLP in this area is estimated at 1000
hPa (buoy NR 14041 at 10Z with a pression of 1001.2 hPa ).
- between 65E and 75E, where convection is strongly southeasterly sheared.
- East of 85E, where convection remains poorly organized.
Avalaible NWP models analyse the low north of Tromelin island, and deepen it progressively with a
quick westwards track towards north of Madagascar, on the northern edge of the subtropical belt
rebuilding southward. Monsoon feeding should remain favourable and trade-wind feeding should
improve. SST are favourable. Upper VWS should remain moderate, north of the upper tropospheric
ridge, and should slow the deepening of this system.
Secondly, NWP models analyse a broad clockwise circulation within the ITCZ, east of 85E, but
don't deepen it significantly. Indeed, this area should remain under strong upper VWS.
For the next 24 hours, the potential for development of a tropical depression is poor. Beyond,
potential becomes fair to important for the low north Tromelin.
http://www.meteo.fr/temps/domtom/La_Reu ... index.html

[Crostorm]

AN AREA OF CONVECTION IS LOCATED NEAR 14.5S 53.7E,
APPROXIMATELY 470 NM NORTHEAST OF ANTANANARIVO, MADAGASCAR. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY DEPICTS A BROAD LOW-LEVEL
CIRCULATION CENTER (LLCC) WITH FORMATIVE BANDING. A 251440Z SSMIS
37GHZ IMAGE ALSO INDICATES AN ELONGATED LLCC WITH STRONG CONVERGENT
BANDING OVER THE SOUTHERN SEMI-CIRCLE AND FRAGMENTED BANDING OVER
THE NORTHERN SEMI-CIRCLE. A RECENT SCATTEROMETER IMAGE OVER THE
EASTERN QUADRANT OF THE LLCC SHOWS 20-25 KNOT WINDS AND SHARP
TROUGHING WHILE LIMTED SURFACE OBSERVATIONS NEAR THE CENTER INDICATE
SLP NEAR 1001MB. UPPER-LEVEL ANALYSIS INDICATES AN IMPROVING
ENVIRONMENT WITH DIFFLUENT EASTERLY FLOW AND GOOD POLEWARD AND
EQUATORWARD OUTFLOW. THE SYSTEM IS EXPECTED TO CONTINUE
STRENGTHENING WHILE TRACKING OVER NORTHERN MADAGASCAR AND WILL
INTENSIFY SIGNIFICANTLY AFTER TAU 24 AS IT MOVES OVER THE MOZAMBIQUE
CHANNEL. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25
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 MEDIUM.

[cycloneye]

Tropical Cyclone Formation Alert

WTXS21 PGTW 260130
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
200 NM EITHER SIDE OF A LINE FROM 13.7S 53.3E TO 14.9S 44.0E
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 25 TO 30 KNOTS. METSAT IMAGERY AT
260100Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 13.7S
51.7E. THE SYSTEM IS MOVING WESTWARD AT 14 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 14.5S
53.7E, IS NOW LOCATED NEAR 13.7S 51.7E, APPROXIMATELY 420 NM
NORTHEAST OF ANTANANARIVO, MADAGASCAR. ANIMATED INFRARED SATELLITE
IMAGERY INDICATES THAT THE SYSTEM HAS CONTINUED TO CONSOLIDATE WITH
INTENSE, DEEP CONVECTIVE BANDING OVER THE SOUTHERN SEMI-CIRCLE
WRAPPING INTO THE SOUTHWEST QUADRANT OF THE LOW-LEVEL CIRCULATION
CENTER (LLCC). A 252320Z AMSU IMAGE ALSO INDICATES IMPROVED
CONVECTIVE BANDING ALTHOUGH THE LLCC APPEARS SLIGHTLY ELONGATED.
UPPER-LEVEL ANALYSIS INDICATES AN IMPROVING ENVIRONMENT WITH
DIFFLUENT EASTERLY FLOW AND GOOD POLEWARD AND EQUATORWARD OUTFLOW.
THE SYSTEM IS EXPECTED TO CONTINUE STRENGTHENING WHILE TRACKING OVER
THE NORTHERN TIP OF MADAGASCAR AND WILL INTENSIFY SIGNIFICANTLY
WITHIN THE NEXT 24 TO 36 HOURS AS IT MOVES OVER THE MOZAMBIQUE
CHANNEL. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30
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
270130Z.//
NNNN

[Crostorm]

[HURAKAN]

Latest visible, continues to gain strength

[HURAKAN]

WTIO30 FMEE 260844 CCA
***************CORRECTIVE**************
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 1/11/20112012
1.A TROPICAL DEPRESSION 11
2.A POSITION 2012/02/26 AT 0600 UTC:
WITHIN 30 NM RADIUS OF POINT 13.2 S / 51.1 E
(THIRTEEN DECIMAL TWO DEGREES SOUTH AND FIFTY ONE DECIMAL ONE
DEGREES EAST)
MOVEMENT : WEST-SOUTH-WEST 15 KT
3.A DVORAK ANALYSIS: 1.5/1.5/D 0.5/12 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: SE: SW: 300 NW: 190
34 KT NE: SE: SW: 220 NW:
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1003 HPA / 900 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : SHALLOW
1.B FORECASTS:
12H: 2012/02/26 18 UTC: 13.6 S / 49.2 E, MAX WIND=020 KT, INLAND
24H: 2012/02/27 06 UTC: 14.6 S / 47.0 E, MAX WIND=020 KT, DISTURBANCE
36H: 2012/02/27 18 UTC: 15.5 S / 45.1 E, MAX WIND=025 KT, TROPICAL DISTURBANCE
48H: 2012/02/28 06 UTC: 15.9 S / 43.5 E, MAX WIND=030 KT, TROPICAL DEPRESSION
60H: 2012/02/28 18 UTC: 16.1 S / 42.1 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
72H: 2012/02/29 06 UTC: 16.1 S / 41.3 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
2.B LONGER-RANGE OUTLOOK :
96H: 2012/03/01 06 UTC: 16.2 S / 40.9 E, MAX WIND=075 KT, TROPICAL CYCLONE
120H: 2012/03/02 06 UTC: 17.9 S / 40.8 E, MAX WIND=080 KT, TROPICAL CYCLONE
2.C ADDITIONAL INFORMATIONS:
T=CI=1.5
CORRECTIVE ABOUT INTENSITY AND WINDS RADII ESTIMATE ACCORDING TO OBS
FROM ANTALAHA AND SAMBAVA THAT HAVE REPORTED GALE FORCE WINDS SINCE06Z.
ALTHOUGHT, CONVECTIVE ACTIVITY STRENGTHENED AND CONCENTRATED
DURING THE LAST 24 HOURS, THE SYSTEM STILL PRESENT AN ILL-DEFINED LOW
LEVEL CIRCULATION WITH A CENTER DIFFICULT TO LOCALISE EVEN WITH MW
IMAGERY.
THE SYSTEM IS MOVING RAPIDLY WESTWARDS ON THE NORTHERN EDGE OF
THESUBTROPICAL RIDGE THAT HAVE BUILT BACK TO THE SOUTH. IT UNDERGOES A
MODERATE EASTERLY CONSTRAINT SO THE CENTER IS ESTIMETED TO BE JUST TO
THE EAST OF THE MAIN CONVECTIVE MASS. THIS PATTERN SHOULD CONTINUE
WITHIN THE NEXT TWO DAYS. ON THIS TRACK, THE SYSTEM SHOULD MAKE
LANDFALL LATER TODAY OVER THE NORTHERN TIP OF MADAGASCAR BETWEEN
DIEGO-SUAREZ AND SAMBAVA (LIKELY NEAR IHARANA). GIVEN THE CURRENT
CONDITIONS AND THE SHORT TIMING BEFORE LANDFALL, SIGNIFICANT
DEVELOPMENT APPEAR AS A LOW PROBABILITY POSSIBILITY. HOWEVER,
ASSOCIATED HEAVY RAINFALLS SHOULD AFFECT LARGE AREAS OF NORTHERN
MADAGASCAR DURING THE NEXT TWO DAYS. RR24H IN THE 100-150 MM ARE
LIKELY.
WEDNESDAY, ENVIRONMENTAL CONDITIONS SHOULD IMPROVE (LOWER SHEAR,
HIGH SST OVER THE MOZAMBIQUE CHANNEL) AND SIGNIFICANT INTENSIFICATION
IS EXPECTED.
BY THAT TIME, THE SYSTEM SHOULD BE INFUENCED BY TWO CONTRADICTORY
STEERING FLOW; ONE ASSOCIATED WITH AN EQUATORIAL RIDGE LOCATED TO ITS
NORTH AND INDUCED AN EASTERLY MOTION AND ANOTHER ONE ASSOCIATED
WITH THE SUBTROPICAL RIDGE LOCATED TO THE SOUTH AND INDUCED A
WESTWARDS MOTION. CONSEQUENTLY, THE TRACK SHOULD SLOW DOWN
SIGNIFICANTLY DURING THE MIDDLE OF NEXT WEEK. BEYOND, THE SUBTROPICAL
RIDGE COULD WEAKEN AND ALLOW A MORE POLEWARDS TRACK.
INHABITANTS OF THE NORTHEASTERN COASTS OF MADAGASCAR AND THE
NORTHERN CHANNEL AREA (INCLUDING THE COMOROS ARCHIPELAGO, THE
NORTHWESTERN COASTS OF MADAGASCAR AND THE MOZAMBIQUE COASTS)
SHOULD CLOSELY MONITOR THE PROGRESS OF THIS SYSTEM.
THE CURRENT INTENSITY OF THIS SYSTEM DOES NOT JUSTIFY THE ISSUANCE OF
REGULAR WARNINGS.

[HURAKAN]

Crossing northern Madagascar

[HURAKAN]

Latest track

[Extratropical94]

Now named Irina:

[HURAKAN]

WTIO30 FMEE 261305
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 2/11/20112012
1.A MODERATE TROPICAL STORM 11 (IRINA)
2.A POSITION 2012/02/26 AT 1200 UTC:
WITHIN 30 NM RADIUS OF POINT 13.8 S / 50.9 E
(THIRTEEN DECIMAL EIGHT DEGREES SOUTH AND FIFTY DECIMAL NINE DEGREES
EAST)
MOVEMENT : WEST-SOUTH-WEST 12 KT
3.A DVORAK ANALYSIS: 1.5/1.5/D 0.5/24 H
4.A CENTRAL PRESSURE: 995 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 40 KT
RADIUS OF MAXIMUM WINDS (RMW) :NIL
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: SE: SW: 300 NW: 310
34 KT NE: SE: SW: 130 NW: 240
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1001 HPA / 600 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : SHALLOW
1.B FORECASTS:
12H: 2012/02/27 00 UTC: 14.2 S / 48.2 E, MAX WIND=020 KT, INLAND
24H: 2012/02/27 12 UTC: 15.2 S / 46.0 E, MAX WIND=025 KT, DISTURBANCE
36H: 2012/02/28 00 UTC: 15.9 S / 44.4 E, MAX WIND=030 KT, TROPICAL DEPRESSION
48H: 2012/02/28 12 UTC: 16.3 S / 42.9 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM
60H: 2012/02/29 00 UTC: 16.4 S / 41.7 E, MAX WIND=050 KT, SEVERE TROPICAL STORM
72H: 2012/02/29 12 UTC: 16.4 S / 41.3 E, MAX WIND=060 KT, SEVERE TROPICAL STORM
2.B LONGER-RANGE OUTLOOK :
96H: 2012/03/01 12 UTC: 16.8 S / 41.0 E, MAX WIND=070 KT, TROPICAL CYCLONE
120H: 2012/03/02 12 UTC: 19.1 S / 40.3 E, MAX WIND=090 KT, INTENSE TROPICAL
CYCLONE
2.C ADDITIONAL INFORMATIONS:
T=CI=1.5
SYNOP REPORT FROM ANTALAHA (BETWEEN 05Z AND 09Z AND THEN AT 12Z),
SAMBAVA (AT 07Z THEN NO OBS) AND DIGO-SUAREZ (BETWEEN 07Z AND 09Z THEN
NO OBS) SHOWN MEAN 10 MIN WINDS IN THE GALE FORCE RANGE (35/45 KT).CONSEQUENTLY, THE MADAGASCAR WEATHER SERVICES NAMED THE SYSTEM
IRINA AT 09Z. THOSE STRONG WINDS SEEMS TO BE ASSOCIATED WITH THE STONG
BURST OF CONVECTION THAT OCCURED THIS MORNING JUST WEST OF THE
ESTIMATED LLCC. THIS CONVECTIVE FEATURES IS NOW COLLAPSING.
DESPITE THIS STRONG WINDS OBSERVED, THE CLOUD PATTERN OF IRINA IS STILL
MILES AWAY FROM A MODERATE TROPICAL STORM SIGNATURE ...
THE SYSTEM IS MOVING RAPIDLY WESTWARDS ON THE NORTHERN EDGE OF
THESUBTROPICAL RIDGE THAT HAVE BUILT BACK TO THE SOUTH. IT UNDERGOES A
MODERATE EASTERLY CONSTRAINT SO THE CENTER IS ESTIMETED TO BE JUST TO
THE EAST OF THE MAIN CONVECTIVE MASS. THIS PATTERN SHOULD CONTINUE
WITHIN THE NEXT TWO DAYS. ON THIS TRACK, THE SYSTEM SHOULD MAKE
LANDFALL WITHIN THE NEXT HOURS OVER THE NORTHERN TIP OF MADAGASCAR
BETWEEN DIEGO-SUAREZ AND SAMBAVA (LIKELY NEAR IHARANA). ASSOCIATED
HEAVY RAINFALLS SHOULD AFFECT LARGE AREAS OF NORTHERN MADAGASCAR
DURING THE NEXT TWO DAYS. RR24H IN THE 100-150 MM ARE LIKELY.
WEDNESDAY, ENVIRONMENTAL CONDITIONS SHOULD IMPROVE (LOWER SHEAR,
HIGH SST OVER THE MOZAMBIQUE CHANNEL) AND SIGNIFICANT INTENSIFICATION
IS EXPECTED.
BY THAT TIME, THE SYSTEM SHOULD BE INFUENCED BY TWO CONTRADICTORY
STEERING FLOW; ONE ASSOCIATED WITH AN EQUATORIAL RIDGE LOCATED TO ITS
NORTH AND INDUCED AN EASTERLY MOTION AND ANOTHER ONE ASSOCIATED
WITH THE SUBTROPICAL RIDGE LOCATED TO THE SOUTH AND INDUCED A
WESTWARDS MOTION. CONSEQUENTLY, THE TRACK SHOULD SLOW DOWN
SIGNIFICANTLY DURING THE MIDDLE OF NEXT WEEK. BEYOND, THE SUBTROPICAL
RIDGE COULD WEAKEN AND ALLOW A MORE POLEWARDS TRACK.
INHABITANTS OF THE NORTHEASTERN COASTS OF MADAGASCAR AND THE
NORTHERN CHANNEL AREA (INCLUDING THE COMOROS ARCHIPELAGO, THE
NORTHWESTERN COASTS OF MADAGASCAR AND THE MOZAMBIQUE COASTS)
SHOULD CLOSELY MONITOR THE PROGRESS OF THIS SYSTEM.

[HURAKAN]

looking better organized

[HURAKAN]

WTIO30 FMEE 261853
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 3/11/20112012
1.A OVERLAND DEPRESSION 11 (EX-IRINA)
2.A POSITION 2012/02/26 AT 1800 UTC:
WITHIN 30 NM RADIUS OF POINT 14.2 S / 49.3 E
(FOURTEEN DECIMAL TWO DEGREES SOUTH AND FORTY NINE DECIMAL THREE
DEGREES EAST)
MOVEMENT : WEST-SOUTH-WEST 18 KT
3.A DVORAK ANALYSIS: NIL
4.A CENTRAL PRESSURE: NIL
5.A MAX AVERAGE WIND SPEED (10 MN): 25 KT
RADIUS OF MAXIMUM WINDS (RMW) :NIL
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: SE: SW: NW: 220
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 0 / 0 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : SHALLOW
1.B FORECASTS:
12H: 2012/02/27 06 UTC: 15.0 S / 47.0 E, MAX WIND=025 KT, TROPICAL DISTURBANCE
24H: 2012/02/27 18 UTC: 15.8 S / 45.2 E, MAX WIND=025 KT, TROPICAL DISTURBANCE
36H: 2012/02/28 06 UTC: 16.2 S / 43.6 E, MAX WIND=030 KT, TROPICAL DEPRESSION
48H: 2012/02/28 18 UTC: 16.4 S / 42.3 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM
60H: 2012/02/29 06 UTC: 16.4 S / 41.6 E, MAX WIND=050 KT, SEVERE TROPICAL STORM
72H: 2012/02/29 18 UTC: 16.5 S / 41.2 E, MAX WIND=060 KT, SEVERE TROPICAL STORM
2.B LONGER-RANGE OUTLOOK :
96H: 2012/03/01 18 UTC: 17.3 S / 40.7 E, MAX WIND=070 KT, TROPICAL CYCLONE
120H: 2012/03/02 18 UTC: 19.6 S / 39.4 E, MAX WIND=090 KT, INTENSE TROPICAL
CYCLONE
2.C ADDITIONAL INFORMATIONS:
IT IS DIFFICULT TO LOCALIZE THE LOW LEVEL CLOCKWISE CIRCULATION, BUT IT IS
VERY LIKELY THAT IRINA HAS MADE ITS LANDFALL AT 1500Z BETWEEN
FANAMBANA AND SAMBAVA. 1500Z SYNOP REPORTS FROM SAMBAVA, DIEGOSUAREZ AND NOSY BE SHOW THAT WINDS HAVE CLEARLY DECREASED. SINCE
1200Z, A CLUSTER HAS BLOWN UP WEST OF LLCC, BUT GENERAL SYSTEMSTRUCTURE IS NOT WELL AND HAS NOT IMPROVED.
WITHIN THE NEXT 48 HOURS, AVAILABLE NWP MODELS ARE IN GOOD AGREEMENT.
SYSTEM IS EXPECTED TO KEEP ON WEST-SOUTHWESTWARD TRACK BY MOVING
RAPIDLY ON THE NORTHERN EDGE OF SUBTROPICAL RIDGE EXISTING TO THE
SOUTH. ON THIS TRACK, IT UNDERGOES A MODERATE TO RATHER STRONG
EASTERLY WINDSHEAR BY GOING ALONG THE NORTH-WESTERN COASTS OF
MADAGASCAR. THIS CONDITIONS MIGHT LIMIT SYSTEM INTENSIFICATION. WITHIN
THE NEXT 2 DAYS, HEAVY RAINFALLS MIGHT AFFECT LARGE AREAS OF NORTHWESTERN MADAGASCAR AND SHOULD TEMPORARY IMPINGE COMOROS
ARCHIPELAGO.
FROM TUESDAY EVENING, ENVIRONMENTAL CONDITIONS SHOULD IMPROVE
(LOWER SHEAR, HIGH SST OVER THE MOZAMBIQUE CHANNEL) AND SIGNIFICANT
INTENSIFICATION IS EXPECTED.
DURING THE SAME TIME, SYSTEM SHOULD BE INFLUENCED BY TWO
CONTRADICTORY STEERING FLOWS ; ONE ASSOCIATED WITH AN EQUATORIAL
RIDGE LOCATED NORTHWARD (INDUCING AN EASTWARD MOTION) AND ANOTHER
ONE ASSOCIATED WITH THE SUBTROPICAL RIDGE LOCATED SOUTHWARD
(INDUCING A WESTWARD MOTION). CONSEQUENTLY, THE TRACK SHOULD
SIGNIFICANTLY SLOW DOWN WITHIN THE MIDDLE OF NEXT WEEK. BEYOND,
SUBTROPICAL RIDGE COULD WEAKEN AND ALLOW A MORE POLEWARD TRACK.
INHABITANTS OF THE NORTHERN CHANNEL AREA (INCLUDING COMOROS
ARCHIPELAGO, NORTH-WESTERN COASTS OF MADAGASCAR AND MOZAMBIQUE
COASTS) SHOULD CLOSELY MONITOR THE EVOLUTION OF THIS SYSTEM.

[HURAKAN]

Latest track

[Chacor]

Down to a 25 kt overland depression.

WTIO30 FMEE 270041
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 4/11/20112012
1.A OVERLAND DEPRESSION 11 (EX-IRINA)
2.A POSITION 2012/02/27 AT 0000 UTC:
WITHIN 40 NM RADIUS OF POINT 14.7 S / 47.9 E
(FOURTEEN DECIMAL SEVEN DEGREES SOUTH AND FORTY SEVEN DECIMAL NINE DEGREES EAST)
MOVEMENT : WEST-SOUTH-WEST 16 KT
3.A DVORAK ANALYSIS: NIL
4.A CENTRAL PRESSURE: NIL
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): 0 / 0 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : SHALLOW
1.B FORECASTS:
12H: 2012/02/27 12 UTC: 15.4 S / 45.9 E, MAX WIND=025 KT, TROPICAL DISTURBANCE
24H: 2012/02/28 00 UTC: 16.0 S / 44.4 E, MAX WIND=025 KT, TROPICAL DISTURBANCE
36H: 2012/02/28 12 UTC: 16.6 S / 43.3 E, MAX WIND=030 KT, TROPICAL DEPRESSION
48H: 2012/02/29 00 UTC: 16.9 S / 42.2 E, MAX WIND=035 KT, MODERATE TROPICAL STORM
60H: 2012/02/29 12 UTC: 16.8 S / 41.4 E, MAX WIND=035 KT, MODERATE TROPICAL STORM
72H: 2012/03/01 00 UTC: 16.5 S / 41.7 E, MAX WIND=045 KT, SEVERE TROPICAL STORM
2.B LONGER-RANGE OUTLOOK :
96H: 2012/03/02 00 UTC: 17.6 S / 40.6 E, MAX WIND=060 KT, SEVERE TROPICAL STORM
120H: 2012/03/03 00 UTC: 18.6 S / 37.2 E, MAX WIND=065 KT, TROPICAL CYCLONE
2.C ADDITIONAL INFORMATIONS:
IT IS VERY DIFFICULT TO LOCALIZE THE LOW LEVEL CLOCKWISE CIRCULATION. CURRENT POSITION IS EXTRAPOL
ED ON LAST AVAILABLE MW (1705Z F18) AND LATEST SATELLITE IR IMAGERY. LLCC IS LIKELY LOCATED INLAND
NEAR ANALALAVA. DEEP CONVECTION IS PRESENT SOUTH OF THE SYSTEM INLAND AND WEST OF THE SYSTEM OVER
SEA (MODERATE EASTERLY VERTICAL WIND-SHEAR). 1828Z ASCAT SWATH IS NOT CENTRED BUT SEEMS TO SHOW A
20/25 KT CLOCKWISE CIRCULATION.
WITHIN THE NEXT 36/48 HOURS, AVAILABLE NWP MODELS ARE IN GOOD AGREEMENT. SYSTEM IS EXPECTED TO KEE
P ON WEST-SOUTHWESTWARD TRACK BY DECELERATING VERY PROGRESSIVELY ON THE NORTHERN EDGE OF SUBTROPIC
AL RIDGE EXISTING TO THE SOUTH. ON THIS TRACK, IT UNDERGOES A MODERATE EASTERLY WINDSHEAR AND MOVE
S ALONG THE NORTH-WESTERN COASTS OF MADAGASCAR. THIS CONDITIONS MIGHT LIMIT SYSTEM INTENSIFICATION
. ASSOCIATED HEAVY RAINFALLS MIGHT AFFECT NORTH-WEST OF MADAGASCAR AND SHOULD TEMPORARY IMPINGE CO
MOROS ARCHIPELAGO.
WEDNESDAY AND THURSDAY, SYSTEM SHOULD BE INFLUENCED BY TWO CONTRADICTORY STEERING FLOWS ; ONE ASSO
CIATED WITH AN EQUATORIAL RIDGE LOCATED NORTHWARD (INDUCING AN EASTWARD MOTION) AND ANOTHER ONE AS
SOCIATED WITH THE SUBTROPICAL RIDGE LOCATED SOUTHWARD (INDUCING A WESTWARD MOTION). CONSEQUENTLY,
SYSTEM COULD REMAIN GLOBALLY QUASI-STATIONARY AND SLOWLY INTENSIFY (WEAKER WIND-SHEAR, FAVOURABLE
SST ON THE MIDDLE OF MOZAMBIQUE CHANNEL).
BEYOND, SUBTROPICAL RIDGE MIGHT BECOME AGAIN THE MAIN STEERING FLOW AND SYSTEM SHOULD TAKE AGAIN A
WEST-SOUTHWESTWARD TRACK BY CONTINUING TO INTENSIFY. UNCERTAINTY IS IMPORTANT FOR THE TRACK AT TH
E END OF FORECAST PERIOD. NWP MODELS FORECAST A MORE OR LESS EARLY LANDFALL ON MOZAMBIQUE (TRACK I
S MORE OR LESS NORTH). ENSEMBLE ECMWF RUN IS ALSO MORE NORTH THAT DETERMINISTIC MODEL. RSMC OFFICI
AL TRACK IS A COMPROMISE OF THESE OPTIONS. INTENSITY HAS BEEN DOWN-GRADED IN REGARD TO PREVIOUS FO
RECAST.
INHABITANTS OF THE NORTHERN CHANNEL AREA (INCLUDING COMOROS ARCHIPELAGO, NORTH-WESTERN COASTS OF M
ADAGASCAR AND MOZAMBIQUE COASTS) SHOULD CLOSELY MONITOR THE EVOLUTION OF THIS SYSTEM.

[Chacor]

Last warning was issued at 0600 UTC.

[HURAKAN]

WTIO30 FMEE 270556
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 5/11/20112012
1.A OVERLAND DEPRESSION 11 (EX-IRINA)
2.A POSITION 2012/02/27 AT 0600 UTC:
WITHIN 30 NM RADIUS OF POINT 15.3 S / 46.8 E
(FIFTEEN DECIMAL THREE DEGREES SOUTH AND FORTY SIX DECIMAL EIGHT
DEGREES EAST)
MOVEMENT : WEST-SOUTH-WEST 14 KT
3.A DVORAK ANALYSIS: NIL
4.A CENTRAL PRESSURE: 996 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 20 KT
RADIUS OF MAXIMUM WINDS (RMW) :NIL
6.A EXTENSION OF WIND BY QUADRANTS (KM):
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1000 HPA / 300 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : SHALLOW
1.B FORECASTS:
12H: 2012/02/27 18 UTC: 16.1 S / 45.4 E, MAX WIND=015 KT, INLAND
24H: 2012/02/28 06 UTC: 17.0 S / 43.6 E, MAX WIND=020 KT, DISTURBANCE
36H: 2012/02/28 18 UTC: 17.2 S / 43.0 E, MAX WIND=025 KT, TROPICAL DISTURBANCE
48H: 2012/02/29 06 UTC: 17.3 S / 42.5 E, MAX WIND=025 KT, TROPICAL DISTURBANCE
60H: 2012/02/29 18 UTC: 17.1 S / 42.2 E, MAX WIND=030 KT, TROPICAL DEPRESSION
72H: 2012/03/01 06 UTC: 17.0 S / 41.7 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
2.B LONGER-RANGE OUTLOOK :
96H: 2012/03/02 06 UTC: 18.4 S / 39.7 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM
120H: 2012/03/03 06 UTC: 19.7 S / 36.8 E, MAX WIND=050 KT, SEVERE TROPICAL STORM
2.C ADDITIONAL INFORMATIONS:
LOW LEVEL CIRCULATION CENTRE REMAINS VERY DIFFICULT TO LOCALIZE.
CURRENT POSITION IS ESTIMATED THANKS TO 0300Z MALAGASY OBSERVATIONS
(NOSY-BE, ATSOHILY AND MAJUNGA).
WITHIN THE NEXT 48 HOURS, AVAILABLE NWP MODELS ARE IN GOOD AGREEMENT.
SYSTEM IS EXPECTED TO KEEP ON TRACKING WEST-SOUTHWESTWARDS AND ONSLOWING DOWN GRADUALLY ON THE NORTHERN EDGE OF SUBTROPICAL RIDGE
EXISTING IN THE SOUTH.
ON THIS FORECAST TRACK, AS IT SHIFTS ALONG THE NORTHWESTERN MALAGASY
COASTLINE, IT IS EXPECTED TO UNDERGO A MODERATE EASTERLY WINDSHEAR.
THIS CONDITIONS MIGHT LIMIT SYSTEM INTENSIFICATION.
ASSOCIATED HEAVY RAINFALLS MIGHT AFFECT THE NORTHWESTERN AREAS OF
MADAGASCAR AN THE EASTERN MOZAMBIQUE COASTLINE (BETWEEN 14S AND
18S) AND SHOULD TEMPORARILY OCCUR OVER MAYOTTE AND COMOROS
ARCHIPELAGO.
WEDNESDAY AND THURSDAY, SYSTEM IS EXPECTED TO UNDERGO TWO OPPOSITE
STEERING INFLUENCES. THE FIRST ONE ASSOCIATED WITH AN EQUATORIAL RIDGE
LOCATED NORTHWARD (INDUCING AN EASTWARD MOTION) AND THE OTHER ONE
ASSOCIATED WITH THE SUBTROPICAL RIDGE LOCATED SOUTHWARD (INDUCING A
WESTWARD MOTION). SYSTEM COULD THEREFORE REMAINS GLOBALLY QUASISTATIONARY AND SLOWLY INTENSIFY (WEAKENING WIND-SHEAR, FAVOURABLE
SST ON THE MIDDLE OF MOZAMBIQUE CHANNEL).
BEYOND, SUBTROPICAL RIDGE MIGHT BECOME BACK THE MAIN STEERING FLOW
AND SYSTEM SHOULD TAKE BACK A WEST-SOUTHWESTWARD TRACK BY
CONTINUING TO INTENSIFY. UNCERTAINTY IS POOR FOR THE TRACK AT MEDIUM
RANGE.
AVAILABLE NWP MODELS FORECAST A MORE OR LESS EARLY LANDFALL ON
MOZAMBIQUE (TRACK IS MORE OR LESS NORTH).
MEMBERS OF THE ECMWF ENSEMBLE SYSTEM IS ALSO LOCATED NORTHERN THAN
THE DETERMINISTIC TRACK.
RSMC OFFICIAL FORECAST TRACK IS A COMPROMISE OF THESE OPTIONS.
FORECAST INTENSITY HAS BEEN DOWN-GRADED COMPARE TO PREVIOUS
FORECAST.
INHABITANTS OF THE NORTHERN CHANNEL AREA (INCLUDING COMOROS
ARCHIPELAGO, NORTH-WESTERN COASTS OF MADAGASCAR AND MOZAMBIQUE
COASTS) SHOULD CLOSELY MONITOR THE EVOLUTION OF THIS SYSTEM.
CURRENT INTENSITY DOES NOT JUSTIFY ISSUANCE OF REGULAR WARNING. IT
REMAINS HOWEVER CLOSELY MONITORED IN RELATIONSHIP WITH ITS POTENTIEL
FOR INTENSIFICATION.
FOR FURTHER INFORMATIONS ABOUT THIS SYSTEM WHEN NO TROPICAL CYCLONE
FORECAST ADVISORY (WTIO30) IS ISSUED, REFER TO BULLETIN AWIO20 FOR
CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER IN THE SOUTHWEST
INDIAN OCEAN ISSUED BY THE RSMC DAILY AT 1200Z.