Bob McDavitt's ideas for sailing weather around the South pacific

30 December 2012

BOBGRAM issued 30 Dec 2012



Issued 30 Dec 2012

Bob McDavitt's ideas for sailing around the South Pacific.

Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the patterned world of weather maps, so please fine-tune to your place. Dates are in UTC unless otherwise stated.

The Atmosphere: Things are changing. The Southern Oscillation Index or SOI (30 day running mean) was hugging the plus 0.5 value since the beginning of September, but during December the 30-day average dropped to minus 1 by 23rd and is now -0.8. An interesting swing towards an El Nino.

As mentioned last time, TC FREDA did indeed form near Solomon Islands a few days ago and is indeed on its way to affect New Caledonia on Mon 31 Dec/Tue 01 Jan. The future track of FREDA is still unsure, but it MAY affect northern NZ on Sat/Sun 5/6 Jan. Stay updated if this is relevant to your excursions.

South Pacific Convergence Zone is active over the Cooks and has developed a tropical depression there. This low is expected to travel south and get knocked a little to the west by a HIGH that is moving away to the east along 45S. This track will take the Low closer to NZ by mid-week where it weakens and that may provide a trough line that will affect FREDA's future track.

There is also a TC off Western Australia called MITCHELL. It is travelling south and grazing the coast. It is expected to move a little to the west as it comes south, and weaken.


See my yotpak at for terms used.

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