BOBGRAM7 issued 6 Sep 2009

WEATHERGRAM

YOTREPS

Issued 6 September 2009  

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

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

 

Special thanks from me to the Tokoroa Weather Watchers who treated me to some fine hospitality last night – that was fun, watching a dry slot move onto the North Island and chatting into the night about barometers, weather maps and severe thunderstorms.

 

TROPICS/SUBTROPICS

TC DUJUAN is wandering northeast off the Philippines this week,  and the Solomons/Micronesia area is likely to have a boost to its convection activity as a Madden Julian pulse of enhanced activity rolls in .

 

As for the South pacific – well, just as last week, the main part of the South Pacific convergence Zone SPCZ is in its northern-most position and is likely to stay put this week as well from Solomons to Tuvalu to Tokelau/Samoa, to Southern Cooks. A burst of convection is likely to visit Samoa on Monday UTC

 

Next weekend, around 12/13 Sep, tropical lows are likely to form to south of New Caledonia and Southern Cooks.  These Lows are likely to deepen into a compact centre that will then move off to the south east. Time any voyages to avoid these lows.

 

SUBTROPICAL RIDGE

A HIGH that is today over New Zealand is expected to become a blocking HIGH and stay put until Wednesdayn9 Sep, and then to move slowly along 30/35S as far as 170W by Sun 13 Sep, with an squash zone of enhanced easterly winds on its northern side in the tropics.  

Another HIGH is expected to form in the Tasman Sea on or around Sat 12 Sep, crossing NZ on 14 /15 Sep.

These Highs are steady enough to help in the timing of your voyages.

 

TASMAN/NZ AREA

A Low over Tasmania is expected to wander eastwards then off southwards over next few days.

Between the HIGHS there is a trough crossing NZ on 11/12 Sep, preceded by strong northerlies. Avoid.

 

 

The terms used are more fully explained in the METSERVICE Yacht Pack.

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