Weathergram- FREDA



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.


TC FREDA at 30 1200UTC with white line showing path so far, colours showing rain about 9 hours prior, and blue (UK) red (GFS) and green (NGP) lines showing model output for future possible tracks.

Taken from Google Earth with the TRMM ( and CIMSS ( overlays added

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 traveling 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.

Weathergram with graphics is

Weathergram text only


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