Tal y como venía comentando en el Seguimiento Tropical, estamos al que muy posiblemente llegue a ser el primer Ciclón Tropical de la temporada por esta cuenta sureña.

La marina lo mantiene bajo vigilancia, pero se esta quedando un poco atrás con sus previsiones, pues el Servicio Meteorológico de Fiji (http://www.met.gov.fj/), comienza a emitir alertas de Depresión Tropical.

CitarTROPICAL DISTURBANCE ADVISORY NUMBER A1 ISSUED FROM RSMC NADI
Dec 10/2004 UTC 2012 UTC.

TROPICAL DEPRESSION 04F CENTRE 1001HPA WAS LOCATED NEAR 14.5S 180 AT
101800 UTC. POSITION GOOD BASED ON HR GMS EIR IMAGERY, RADAR IMAGERY
AND PERIPHERAL SURFACE REPORTS.  CYCLONE MOVING EAST-SOUTHEAST AT
ABOUT 8 KNOTS. MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE
ESTIMATED AT ABOUT 20 KNOTS.

OVERALL ORGANISATION AND CONVECTION HAS INCREASED IN THE PAST 24
HOURS. SYSTEM LIES UNDER AN UPPER DIFFLUENT REGION IN A LOW SHEARED
ENVIRONMENT. TD04F IS BEING STEERED EAST-SOUTHEAST BY WEST-SOUTHWEST
DEEP LAYER MEAN WIND. DVORAK ANALYSIS BASED ON 0.2 WRAP GIVING
DT=1.5, MET AND PT AGREE. FT BASED ON DT THUS YIELDING
T1.5/1.5/D0.0/24HRS. SST AROUND 29 DEGREES CELCIUS.
MOST GLOBAL MODELS AGREE ON A EASTWARDS MOVEMENT WITH FURTHER
DEVELOPMENT.
POTENTIAL FOR THIS SYSTEM TO DEVELOP INTO A TROPICAL CYCLONE IN THE
NEXT 24 TO 48 HOURS IS MODERATE.

FORECASTS :
AT 12 HRS VALID AT 110600 UTC 14.5S 178.7W MOV E AT 06 KT WITH 20 KT
CLOSE TO CENTRE
AT 24 HRS VALID AT 111800 UTC 14.0S 177.3W MOV ENE AT 07 KT WITH 25
KT CLOSE TO CENTRE

OUTLOOK :
AT 36 HRS VALID AT 120600 UTC 13.6S 175.4W MOV ENE AT 08 KT WITH 30
KT CLOSE TO CENTRE
AT 48 HRS VALID AT 121800 UTC 13.3S 173.8W MOV ENE AT 09 KT WITH 30
KT CLOSE TO CENTRE

THE NEXT TROPICAL DISTURBANCE ADVISORY ON TD04F WILL BE ISSUED AROUND
1102000 UTC.

91PINVEST.15kts-1010mb-142S-1795E 

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No puedo mirar el tema de la cizalladura desde la pagina del CIMSS, ¿Alguien sabe de algún otro sitio?.

Gracias 

Lanzada alerta por formación ciclónica por parte de los americanos, de momento aumenta ligeramente su fuerza 04PFOUR.30kts-1000mb-145S-1767W, y destacar la formación de más que una banda en espiral convectiva, donde la más oriental, a estado azotando las isla de Samoa.

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Adjunto algunos enlaces de los diferentes organismos oficiales que hay por la zona.

Samoa Meteorological Division
http://www.mnre.gov.ws/meteorology/forecast.htm
Fidji Meteorological Service
http://www.met.gov.fj/
Météo France Calédonie
http://www.meteo.nc/
Météo France Polynésie
http://www.meteo.pf/
Vanuatu Meteorological Service
http://www.meteo.gov.vu/Home/tabid/36/Default.aspx
Cook Islands Meteorological Service
http://informet.net/ckimet/
Tonga Meteorological Service
http://www.met.gov.to/
Salomon Island Meteorological Service
http://www.met.gov.sb/

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La marina eleva vientos de Tormenta Tropical 04PFOUR.35kts-996mb-143S-1756W, pico máximo previsto de 100 KT, y directo a Samoa como un potente ciclón.



El Servicio M. de Fiji de momento lo mantiene como DT.

TROPICAL DISTURBANCE ADVISORY NUMBER A5 ISSUED FROM RSMC NADI
Dec 11/1938 UTC 2012 UTC.

TROPICAL DEPRESSION 04F CENTRE 998HPA WAS LOCATED NEAR 14.6S 175.5W
AT 111800 UTC. POSITION POOR BASED ON HR GMS IR/VIS IMAGERY AND
PERIPHERAL SURFACE REPORTS.  DEPRESSION MOVING EAST AT ABOUT 12
KNOTS. MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT
ABOUT 30 KNOTS.

OVERALL ORGANISATION AND CONVECTION HAS IMPROVED IN THE PAST 24
HOURS. CLOUD TOPS COOLING PAST 3 HOURS. SYSTEM LIES UNDER AN UPPER
DIFFLUENT REGION IN A LOW TO MODERARTE SHEARED ENVIRONMENT. TD04F IS
BEING STEERED EAST BY DEEP LAYER MEAN WESTERLY WIND. DVORAK ANALYSIS
BASED ON 0.4 WRAP GIVING DT=2.5, MET=2.5 AND PT=2.5. FT BASED ON DT
THUS YIELDING T2.5/2.5/D1.0/24HRS. SST AROUND 30 DEGREES CELCIUS.

Pero con un pronostico en cuanto al Track, similar al del JTWC, aunque difiere en cuanto a intensidad.

Ya tenemos al 04.F como Tormenta Tropical por los dos organismos que lo siguen de manera oficial. Nombrada por el Centro Meteorológico Regional especializado en ciclones tropicales de Fiji con el nombre de EVAN. Evan registra vientos de 74 klm/h (1 minuto), rachas de 93 klm/h, y una presión mínima estimada en su centro de 993 hPa.

04PEVAN.40kts-993mb-141S-1739W

Evan se encuentra a unos 400 kilómetros al oeste de Apia (Samoa), y  a 750 kilómetros al noreste de Suva (Fiji), moviéndose dirección este, a una velocidad de 20 klm/h.

Evan debería seguir intensificándose  con el paso de las horas bajo unas condiciones ambientales bastante favorables en las próximas 48 horas.



SST que ronda los 29 Cº, OHC marcando valores moderadamente altos, cizalladura favorable (5-10 KT) durante unas 36-48 horas, aunque aumentará progresivamente una vez vire direeción W-SW, rumbo Nadi.

Pronostico Fiji



Pronostico JTWC



Demasiado cerca del Ecuador para que haga "BOOM", pero Evan viene fuerte y muy prometedor... 

04PEVAN.50kts-985mb-139S-1732W

Da la sensación que se está intensificando a marchas forzadas desde hace unas pocas horas. 

Pues parece que si esta inmerso en un ciclo de rápida intensificación. 



Samoa 

Ciclón Tropical Categoría 1 para Fiji.

TROPICAL DISTURBANCE ADVISORY NUMBER A7 ISSUED FROM RSMC NADI
Dec 12/0805 UTC 2012 UTC.

TROPICAL CYCLONE EVAN 04F CENTRE 990HPA WAS LOCATED NEAR 14.1S 174.1W
AT 120600 UTC. POSITION FAIR BASED ON HR GMS IR IMAGERY AND
PERIPHERAL SURFACE REPORTS. CYCLONE MOVING EAST AT ABOUT 4 KNOTS.
MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT ABOUT 40
KNOTS.

EXPECT WINDS ABOVE 33 KNOTS WITHIN 100 NAUTICAL MILES IN NE QUADRANT
AND WITHIN 70 NAUTICAL MILES IN SE QUADRANT
AND WITHIN 70 NAUTICAL MILES IN SW QUADRANT
AND WITHIN 100 NAUTICAL MILES IN NW QUADRANT.

DEEP CONVECTION HAS INCREASED IN THE PAST SIX HOURS. CLOUD TOPS
COOLING. THE CYCLONE LIES UNDER AN UPPER DIFFLUENT REGION. OUTFLOW
GOOD TO THE SOUTH. SYSTEM LIES IN A MODERATE SHEARED ENVIRONMENT AND
IS BEING STEERED EASTWARDS BY A WESTERLY DEEP LAYER MEAN FLOW. SST
AROUND 30 DEGREES CELCIUS.
DVORAK ANALYSIS BASED ON CENTRAL CLOUD COVER PATTERN, YIELDING DT OF
3.0. MET AND PT AGREE. FT BASED ON MET. THUS, T3.0/3.0/D0.5/24HRS.

GLOBAL MODELS MOVE THIS SYSTEM EASTWARDS WITH SOME INTENSIFICATION.

Categoría 2 e intensificándose Evan.

TROPICAL CYCLONE EVAN CENTRE 985HPA CATEGORY 2 WAS LOCATED NEAR 13.9
SOUTH 172.8 WEST AT 121200 UTC.
POSITION FAIR.
REPEAT POSITION 13.9S 172.8W at 121200 UTC.
CYCLONE MOVING EAST AT 13 KNOTS. CYCLONE INTENSIFYING.
EXPECT SUSTAINED WINDS OF 50 KNOTS CLOSE TO THE CENTRE.

EXPECT SUSTAINED WINDS OVER 47 KNOTS WITHIN 30 NAUTICAL MILES OF
CENTRE AND
OVER 33 KNOTS WITHIN 120 NAUTICAL MILES IN NE QUADRANT
          AND WITHIN 80 NAUTICAL MILES IN SE QUADRANT
          AND WITHIN 80 NAUTICAL MILES IN SW QUADRANT
          AND WITHIN 120 NAUTICAL MILES IN NW QUADRANT.

FORECAST POSITION NEAR 13.8S 171.7W AT 130000 UTC
              AND NEAR 13.8S 171.3W AT 131200 UTC.

THIS WARNING CANCELS AND REPLACES WARNING 019.

El AMSUB muestra anillo convectivo, asi que si no fluctua, mañana ya será Huracán

No hace falta esperar a mañana, Evan sigue cabreado y alcanza la categoría de Huracán. 

04PEVAN.65kts-974mb-141S-1720W

RECENT ANIMATED INFRARED SATELLITE IMAGERY SHOWS
A NARROW RING OF DEEP CONVECTION PERSISTING AROUND A SMALL
DEVELOPING EYE EVIDENT IN THE AFOREMENTIONED TRMM IMAGE.

La marina actualiza y rectifica su Track, lo mandan un poco más al este de lo que estaba previsto, por lo que podrá afectar también a la isla de Pago Pago.

Animación RGB