SW Indian Ocean: Tropical Depression Three (ex-BONGWE)

[Squarethecircle]

I'm betting 10 bucks this thing makes hurricane-equivalent status before dying in the extreme South Indian.

Told you .

[CrazyC83]

Reunion forecasting this to become a tropical cyclone (65 kt+ in 10 min winds)...

[Squarethecircle]

Well, they can't exactly not forecast it to become that strong now, can they?

[P.K.]

Upgraded to 50kts this morning.

BULLETIN DU 19 NOVEMBRE A 16H30 LOCALES:

IL N'Y A PAS D'ALERTE EN COURS A LA REUNION, ET AUCUNE
MENACE CYCLONIQUE N'EST ENVISAGEE POUR LES PROCHAINES 72 HEURES.
*****************************************************



NATURE DU SYSTEME DEPRESSIONNAIRE TROPICAL
PRESENT SUR LE SUD-OUEST DE L'OCEAN INDIEN


FORTE TEMPETE TROPICALE BONGWE

PRESSION ESTIMEE AU CENTRE : 987 HPA.
POSITION LE 19 NOVEMBRE A 16 HEURES LOCALES: 10.4 SUD / 76.8 EST
(DIX DEGRES QUATRE SUD ET SOIXANTE-SEIZE DEGRES HUIT EST).

DISTANCE DES COTES REUNIONNAISES: 2535 KM A L'EST-NORD-EST
DEPLACEMENT: SUD-SUD-OUEST A 12 KM/H.

VOICI LES INTENSITES ET POSITIONS PREVUES DE CE SYSTEME DEPRESSIONNAIRE AU COURS DES PROCHAINS JOURS

CYCLONE TROPICAL, CENTRE POSITIONNE DANS 24H PAR 11.4S/74.8E
CYCLONE TROPICAL, CENTRE POSITIONNE DANS 48H PAR 12.4S/71.8E
CYCLONE TROPICAL, CENTRE POSITIONNE DANS 72H PAR 12.6S/69E


ATTENTION: LES PREVISIONS DE TRAJECTOIRE ET D'INTENSITE
PRECEDENTES SONT A CONSIDERER AVEC LA PLUS GRANDE PRUDENCE
COMPTE TENU DE LEUR INCERTITUDE. ELLES NE CONCERNENT QUE LA
POSITION DU CENTRE DU PHENOMENE, SANS CONSIDERATION SUR SON
EXTENSION.




CE BULLETIN EST A PRESENT TERMINE.
CE BULLETIN SERA REACTUALISE CE SOIR A 22H30 LOCALES.

[HURAKAN]

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

----- Current Analysis -----
Date : 19 NOV 2007 Time : 133000 UTC
Lat : 10:23:51 S Lon : 76:44:51 E

CI# /Pressure/ Vmax
3.5 / 988.2mb/ 55.0kt
6hr-Avg T# 3hr-Avg T# Adj T# Raw T#
3.3 3.4 3.3 3.3

Latitude bias adjustment to MSLP : +4.2mb

Center Temp : -78.0C Cloud Region Temp : -69.7C

Scene Type : UNIFORM CDO CLOUD REGION

Positioning Method : FORECAST INTERPOLATION

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

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

****************************************************

[HURAKAN]

19/1430 UTC 10.2S 76.5E T3.5/3.5 BONGWE -- South Indian Ocean

[HURAKAN]

[Squarethecircle]

Woohoo! Hurricane strength from the JTWC; here we go again!

[WindRunner]

:uarrow: Remember that you're looking at the Southern Hemisphere, which means that if a cyclone is moving south, it's moving poleward, not equatorward.

Correct, a SW track would be like a NE track in the Northern Hemisphere.

Actually, a SW track would be like a NW track in the Northern Hemisphere . . . mid-level flow is still westerly, hence a "recurving" system (NE movement in the north Atlantic) would be on a SE track in the Southern Hemisphere.

[CrazyC83]

WTIO30 FMEE 191837

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER : 6/3/20072008
1.A SEVERE TROPICAL STORM 3 (BONGWE)
2.A POSITION 2007/11/19 AT 1800 UTC :
11.0S / 76.6E
(ELEVEN DECIMAL ZERO DEGREES SOUTH AND SEVENTY SIX DECIMAL SIX DEGREES
EAST)
3.A DVORAK ANALYSIS : 3.0/3.5 MOINS /D 1.0/24 H
4.A CENTRAL PRESSURE : 987 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 50 KT
6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 060 SE: 120 SO: 120 NO: 060
50 KT NE: 030 SE: 030 SO: 030 NO: 030
7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1010 HPA / 700 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP
1.B FORECASTS:
12H: 2007/11/20 06 UTC: 11.8S/75.8E, MAX WIND=050KT, SEVERE TROP. STORM.
24H: 2007/11/20 18 UTC: 12.4S/74.5E, MAX WIND=060KT, SEVERE TROP. STORM.
36H: 2007/11/21 06 UTC: 13.0S/73.0E, MAX WIND=065KT, TROPICAL CYCLONE.
48H: 2007/11/21 18 UTC: 13.4S/71.6E, MAX WIND=070KT, TROPICAL CYCLONE.
60H: 2007/11/22 06 UTC: 13.7S/70.3E, MAX WIND=080KT, TROPICAL CYCLONE.
72H: 2007/11/22 18 UTC: 13.7S/68.8E, MAX WIND=080KT, TROPICAL CYCLONE.
2.B OTHER INFORMATIONS:
T=3.0+ AND CI=3.5
LAST MICRO-WAVE IMAGERIES (SSMIS AT 1514Z AND SSMI AT 1345Z) HAS FIXED
THE LOCATION OIF THE LLCC, AND SHOWN A LIGHT SOUTHEASTWARDS VERTICAL
WINDSHEAR, WHICH PUSHES DEEP CONVECTION NORTHWESTWARDS AND TEMPORARILLY
STOP THE INTENSIFICATION. NEVERTHELESS BONGWE REMAINS IN AN ENVIRONMENT
RATHER FAVORABL
E FOR INTENSIFICATION, AND SHOULD REACH TROPICAL CYCLONE INTENSITY DURING
THE NEXT 48 HOURS.
THE SOUTHWESTWARDS TRACK IS CONFIRMED. "BONGWE" IS NOW UNDER THE STEERING
INFLUENCE OF THE SUBTROPICAL RIDGE, WHICH STEERES IT GLOBALLY WESTARDS.
GUIDANCE HAS BEEN SLIGHTY ADJUSTED CLOSELY ECMWF AND EPS'S TRACKS. THIS
SCENARIO IS ADOPTED BY MOST OF THE NWP MODELS.

[CrazyC83]

Now JTWC is forecasting Cat 2 and M-F is forecasting an 80 kt (10-min) cyclone...

[Squarethecircle]

Now JTWC is forecasting Cat 2 and M-F is forecasting an 80 kt (10-min) cyclone...

At least there's no land in front of it.

[HURAKAN]

[HURAKAN]

[HURAKAN]

[CrazyC83]

WTIO30 FMEE 200037

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER : 7/3/20072008
1.A SEVERE TROPICAL STORM 3 (BONGWE)
2.A POSITION 2007/11/20 AT 0000 UTC :
10.9S / 75.9E
(TEN DECIMAL NINE DEGREES SOUTH AND SEVENTY FIVE DECIMAL NINE DEGREES
EAST)
3.A DVORAK ANALYSIS : 4.0/4.0 MOINS /D 1.5/24 H
4.A CENTRAL PRESSURE : 980 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 55 KT
6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 100 SE: 140 SO: 140 NO: 100
50 KT NE: 035 SE: 035 SO: 035 NO: 035
7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1010 HPA / 700 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP
1.B FORECASTS:
12H: 2007/11/20 12 UTC: 11.5S/74.4E, MAX WIND=060KT, SEVERE TROP. STORM.
24H: 2007/11/21 00 UTC: 12.1S/72.8E, MAX WIND=065KT, TROPICAL CYCLONE.
36H: 2007/11/21 12 UTC: 12.6S/71.3E, MAX WIND=070KT, TROPICAL CYCLONE.
48H: 2007/11/22 00 UTC: 13.1S/70.2E, MAX WIND=075KT, TROPICAL CYCLONE.
60H: 2007/11/22 12 UTC: 13.4S/69.0E, MAX WIND=080KT, TROPICAL CYCLONE.
72H: 2007/11/23 00 UTC: 13.5S/67.9E, MAX WIND=080KT, TROPICAL CYCLONE.
2.B OTHER INFORMATIONS:
T=4.0- AND CI=4.0-
THE LOCATION OF THE CENTER IS ESTIMATED WITH A RATHER GOOD CONFIDENT
ACCORDING TO LAST MICRO-WAVE IMAGERIES (MAINLY IMAGE OF AQUA AT 2025Z IN
THE 37CHZ/V CHANNEL WHICH SHOWS A SMALL LOW LEVEL EYE IN THE HEAD OF THE
CURVED BAND AND AN IMROVING ORGANIZATION). THE CENTER HAS BEEN SLIGHTLY
RELOCATED TO
THE NW COMPARED TO THE LOCATION INDICATED AT 1800Z.
"BONGWE" HAS TRACKED WESTSOUTHWESTWARDS DURING THE LAST 6 HOURS, UNDER
THE STEERING INFLUENCE OF THE SUBTROPICAL RIDGE, WHICH STEERES IT
GLOBALLY WESTARDS.
IN AN ENVIRONMENT RATHER FAVORABLE FOR INTENSIFICATION, BONGWE SHOULD
REACH TROPICAL CYCLONE INTENSITY DURING THE NEXT 24 HOURS.
GUIDANCE HAS BEEN ADJUSTED CLOSELY TO ECMWF AND EPS'S TRACKS.

[HurricaneRobert]

It's not headed to Madagascar is it?

[HURAKAN]

It's not headed to Madagascar is it?

So far pretty far from Madagascar.



Looking really good.

[Chacor]

Interesting discussion from MF.

WTIO30 FMEE 201238

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER : 9/3/20072008
1.A SEVERE TROPICAL STORM 3 (BONGWE)

2.A POSITION 2007/11/20 AT 1200 UTC :
WITHIN 30 NM RADIUS OF POINT 11.6S / 74.0E
(ELEVEN DECIMAL SIX DEGREES SOUTH AND SEVENTY FOUR DECIMAL ZERO DEGREES
EAST)

3.A DVORAK ANALYSIS : 3.0/3.5 /W 0.5/12 H
4.A CENTRAL PRESSURE : 985 HPA
5.A MAX AVERAGE WIND SPEED (10 MN) : 50 KT

6.A EXTENSION OF WINDS BY QUADRANTS (KM):
30 KT NE: 100 SE: 150 SO: 250 NO: 250
50 KT NE: 030 SE: 030 SO: 030 NO: 030

7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1010 HPA / 700 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP

1.B FORECASTS:
12H: 2007/11/21 00 UTC: 12.1S/72.7E, MAX WIND=040KT, MODERATE TROP. STORM
.
24H: 2007/11/21 12 UTC: 12.5S/71.6E, MAX WIND=040KT, MODERATE TROP. STORM
.
36H: 2007/11/22 00 UTC: 12.8S/70.8E, MAX WIND=050KT, SEVERE TROP. STORM.
48H: 2007/11/22 12 UTC: 13.0S/70.1E, MAX WIND=050KT, SEVERE TROP. STORM.
60H: 2007/11/23 00 UTC: 13.1S/69.7E, MAX WIND=050KT, SEVERE TROP. STORM.
72H: 2007/11/23 12 UTC: 13.1S/69.2E, MAX WIND=050KT, SEVERE TROP. STORM.

2.B OTHER INFORMATIONS:
T=3.0 AND CI=3.5

"BONGWE" IS SUFFERRING TODAY IN ONE HAND WITH SOME SLIGHT EASTERLY WIND
SHEAR BUT MORE PROBABLY WITH SOME INTRUSION OF DRY AIR FROM THE WEST AS
IT CAN BE CLEARLY SEEN IN THE MIMIC-TPW PRODUCT FROM CIMSS
...CONSEQUENTLY, CURRENT INTENSITY HAS BEEN LOWERED TO 50 KT.

THE BIG QUESTION FOR THE INTENSITY FORCAST IS TO KNOW IF THE DRY AIR
INTRUSION IS JUST TEMPORARY OR NOT ....
PRESENT FORECAST CALL NOW FOR A SLIGHT DECREASE IN STRENGH FOR THE NEXT
24 HOURS THAT SHOULD BRING BACK "BONGWE" TO MODERATE TROPICAL STORM
STATUS THEN AN INCREASE TO SEVERE TROPICAL STORM STATUS AGAIN.

TRACK HAS BEEN NEAR DUE WEST DURING THE LAST SIX HOURS, SO GUIDANCE HAS
BEEN ADJUST TO THE RIGHT.
AFTER DAY 1, SOME RELIABLE MODELS (AS GFDN, GFS) SLOW DOWN A LOT THE
SYSTEM AND EVEN RECURVE THE TRACK SOUTH-EASTWARDS AS "BONGWE" COULD BE
AGAIN ON THE INFLUENCE OF THE MID-LEVEL RIDGE THAT IS STILL NORTH-EAST OF
THE SYSTEM. THE PRESENT GUIDANCE DOESN'T REFLECT THIS SCENARIO BUT
STILL FOLLOWS THE
ECMWF AND EPS TRACKS WITH A WESTWARDS TRACK, BUT SLOW DOWN "BONGWE" AT
DAY 2 AND 3.

[HURAKAN]

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

----- Current Analysis -----
Date : 20 NOV 2007 Time : 123000 UTC
Lat : 12:08:14 S Lon : 74:36:59 E

CI# /Pressure/ Vmax
3.0 / 994.7mb/ 45.0kt

6hr-Avg T# 3hr-Avg T# Adj T# Raw T#
2.5 2.4 2.5 2.5

Latitude bias adjustment to MSLP : +3.7mb

Center Temp : -16.3C Cloud Region Temp : -34.7C

Scene Type : CURVED BAND with 0.33 ARC in DK GRAY
Maximum CURVED BAND with 0.44 ARC in DK GRAY
at Lat: 12:55:48 S Lon: 75:12:35 E

Positioning Method : FORECAST INTERPOLATION

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

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

****************************************************