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

13 November 2010

BOBGRAM7 issued 14 Nov 2010

Issued 14 November 2010
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.

TROPICS Low 1006 hPa or less near 16S 176E or over NW Fiji this evening
Sun 14 Nov is moving SSE and should then move S then SW and fade near
Norfolk island from Tue 16 to Thu 18 Nov. Avoid the strong winds on
south side of this low and squally showers on its South and Southeast
sides. This means it is not the best week to sail from New Caledonia
to NZ.

The South Pacific Convergence Zone SPCZ has a branch from that LOW that
stretches off to the SE over Southern Tonga: this is weakening but
should wander east across Niue on Tue 16 Nov and Southern cooks on Wed
17 Nov. Another branch is building from east of Solomons towards Tuvalu
along 6 to 9S - this should gradually extend to Samoa and to Southern
Cooks during the coming week, with a drop in pressure. There is
another active branch north of French Polynesia FP between 11 and 17 S,
and models expect this to fade.

Coral Sea may turn into a breeding ground around 23 to 27 Nov.

HIGH is expected to wander east over north of North Island on Mon 15 Nov
and then off to the east along 35 to 40S from Tue 16 to Sat 20 Nov when
it gets south of FP. There is likely to be a squash zone of enhanced
easterly winds along the north side of this High along 20 to 25S.

The SW flow that swiped over NZ today 14 Nov is likely to be injected
into the back of a trough south of Southern Cooks by Tue 16 Nov helping
intensify a LOW near 35S 155W that may then go through a rapid deepening
process and it shoots off to the SE.
Next High should wander east along 35S across the Tasman Sea slowly from
Fri 19 to Wed 24 Nov, and also have a squash zone of enhanced easterly
winds on its northern side over New Caledonia.

A trough (the one that upset Tasmanian grand prix today) is expected to
stall over southern NZ on Mon/Tue/Wed 15/16/17 Nov making for a strong W
to NW flow over central and southern areas, and light winds for
Northland. Then a broad trough is expected to cross NZ slowly from
Friday 19 to Sun 21 Nov.

SPCZ squalls and rough seas over southern Fiji and just south of Tonga
tonight and Monday.
Winds over Northland should be a useful NE to N from Thu 18 to Sat 20
Nov, then that weekend trough is likely to swing to wind to a SW/S from
Sun 21 to Wed 24 Nov -nothing major, but sailors may need to work out a
waypoint that positions them Ok for those SW winds early next week.

The HIGH SEAS email link I gave last week has suffered link rot. You
can get MetService HIGH SEA warnings via email to, no
subject needed, with message SEND Or, for latest BRETT coastal,

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