APCEDI Alert SP/FJ Tropical Depression 12F #1-2006: Tropical Depression 12F threatens to Form Cyclone, Threatens Tonga

The RSMC-Nadi Tropical Cyclone Centre and the Joint Typhoon Warning Centre are issuing guidance on Tropical Depression 12F that is threatening to form into Cyclone between Niuafo'ou and the Vava'u Group.

Cyclone 12F formed several days ago near the Territory of Wallis and Futuna and has been steadily strengthening. The system has become very organised throughout and day, and may become a cyclone later tonight or early tomorrow..

Tropical Depression 12F is located about 120 kilometres south-east of Niuafo'ou or 220 kilometres north-northwest of Vava'u and 430 kilometres north of Nukualofa at 1101000 UTC. The Depression is now moving southeast about 07 knots and expected to intensify further and become a tropical cyclone in the next 12 to 24 hours.

All interests in Tonga, Niue, and the Cook Islands should closely monitor the progress of this storm, and undertake any actions as advised by the local authorities. Although the storm is moving away from Wallis and Futuna, Fiji and Samoa, all interests should maintain vigilance due to continuing rough seas, winds and heavy rains.

CURRENT ADVISORIES AND WARNINGS

TONGA
A TROPICAL CYCLONE ALERT IS NOW IN FORCE FOR TONGA.
A STRONG WIND WARNING IS IN FORCE FOR THE WHOLE OF TONGA.

SAMOA
WIND ADVISORY IN FORCE FOR SAMOA
FLOOD ADVISORY REMAINS IN FORCE
LANDSLIDE ADVISORY REMAINS IN EFFECT

NIUE
STRONG WIND WARNING

WALLIS AND FUTUNA
A STRONG WIND WARNING IN FORCE FOR WALLIS AND FUTUNA WATERS.

AMERICAN SAMOA
SMALL CRAFT ADVISORY
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From the RSMC-Nadi Tropical Cyclone Centre

Tropical Disturbance Advisory Number A4 issued from RSMC NADI
Feb 11/0205 UTC 2006 UTC.

Tropical Depression 12F [999 hPa] centre was re-located near 16.6S 174.9W at 110000 UTC moving southeast 07 knots. Position poor based on MTSTAT EIR/VIS with animation, Quikscat and SSM/I data and peripheral surface reports. Maximum 10-minute average winds estimated at 25 to 30 knots close to the centre possibly increasing to 35 knots, and extending to within 60 miles of centre in the next 12 to 24 hours.

Organisation undergone marked improvement past 6 hours. Primary band still developing but beginning to wrap around llcc. 12F still lies just south of upper 250-hPa outflow, in a diffluent region and 20 to 25-knot shear. Dvorak analysis based on .40 on log10 spiral giving a T2.5. PT=MET=2.0 Thus, T2.0/2.0/D1.0/24hrs. The system is expected to be steered generally towards the south by a mid-level ridge to southeast. SST in the area is about 29-30C. Some global models agree on a future southward track with further intensification. The potential for 12F to develop into a tropical cyclone in the next 24 hours is moderate to high.

The next Tropical Disturbance Advisory on TD 12F will be issued around 110800 UTC.
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The TONGA FORESCAST from RSMC-Nadi Tropical Cyclone Centre

Special Weather Bulletin Number FOUR for Tonga on TROPICAL DEPRESSON 12F issued from RSMC NADI
Feb 11/0332 UTC 2006 UTC.

TROPICAL CYCLONE ALERT.

A TROPICAL CYCLONE ALERT IS NOW IN FORCE FOR TONGA.
A STRONG WIND WARNING IS IN FORCE FOR THE WHOLE OF TONGA.

Tropical Depression 12F [999 hPa] centre was re-located near 16.6 South 174.9 West or about 75 miles south-east of Niuafo'ou or 135 miles north-northwest of Vava'u and 270 miles north of Nukualofa at 1101000 UTC. The Depression is now
moving southeast about 07 knots and expected to intensify further and become a tropical cyclone in the next 12 to 24 hours.

If this happens, winds may gradually increase to damaging gale force especially over the central and southern parts of Tonga within the next 24 hours.

FOR NIUAFO'OU AND NIUATOPUTAPU:
Northwest winds 20 to 25 knots possibly increasing to damaging gale force with average speeds to 35 knots and momentary gust to 50 knots. Rain, heavy at times with squally thunderstorms. Flooding of low lying areas, including sea flooding of low-lying coastal areas possible. Rough to very rough seas. Moderate to heavy swells.

FOR THE REST OF TONGA:
South to southeast winds 20 to 25 knots with gusts to 35 knots. Winds expected to gradually increase to damaging gale force with average speeds of 35 to 40 knots and momentary gusts of 50 to 60 knots in the next 24 to 36 hours. Periods of heavy rain developing with some squally thunderstorms. Flooding including sea flooding of low-lying coastal areas expected. Very rough to high seas. Damaging heavy swells developing.

THE FOLLOWING INFORMATION IS PROVIDED ESPECIALLY FOR MARINERS:
Clockwise winds may increase to 35 knots within 60 miles of centre in the next 24 hours. High seas. Heavy swells.

The next Special Weather Bulletin for Tonga on Tropical Depression 12F will be issued at 110800 UTC. TONGA PSE ACKNOWLEDGE THE RECEIPT.
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APCEDI will continue to monitor the progress of this system

Kevin Vang
APCEDI Coordinator
http://www.afap.org/apcedi/

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