Weekly Pacific Weather - Bob McDavit

[southernman]

to those of us cruising the South Pacific Bob McDavit is the local weather God. Here is his latest predictions:

WEATHERGRAM
YOTREPS
Issued 19 Feb 2006
Bob McDavitt's ideas for South Pacific sailing weather.
(Standard 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).

SOUTH PACIFIC CONVERGENCE ZONE SPCZ is going through a quiet period at present and extends from Tuvalu to Tokelau to Northern Cooks to southern French Polynesia. It is expected to move southwards and westwards during the week, reaching Fiji to Southern Cooks on Wednesday/Thursday (utc).
There are westerly winds on its northern side and these might help to wind up a tropical low near the Solomons on Monday that may –according to today’s run of the GFS model- move SE between Vanuatu and Fiji on Thursday. During next weekend the chances rise that a tropical low might develop in the Coral Sea. The risk of Tropical cyclone formation is low this week but is expected to rise next week and climax in early march.

SUBTROPICS: The trade winds are being well maintained between 180 and Australia thanks to high pressures that keep reforming in the Tasman Sea.

NEW ZEALAND: a zone of hot NW winds are crossing the Tasman Sea today and should cross the South Island on Monday ahead of a weakening front. These NW winds will help get the VOLVO Round-the–world Ocean race fleet into the southern ocean quickly. They left on Leg 4 to Rio de Janiero on Sunday (utc). Another more pronounced front is expected to cross NZ on Wednesday and Thursday followed by cooling south/southwest winds that should remain in place for the coming weekend. Further similar fronts are forecast to follow this pattern next week.

[southernman]

Bob McDavitt's ideas for South Pacific sailing weather.
(Standard 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).

SOUTH PACIFIC CONVERGENCE ZONE SPCZ is still going through a quiet period and its main branch has been taken all the way south of 20S (from 180 to
150W) and over Vanuatu. OK, TC KATE had a go in the northern Coral Sea but
has faded, and last week’s Low did as the computers expected – found the gap between Vanuatu and Fiji and took that south and is now fading.

This week the computers are not picking any cyclones to form in the South pacific. They are picking that the SPCZ over Vanuatu will end up drifting
west and south and pressures remain LOW in the Coral Sea. This will
combine with Highs crossing Tasmania to form a squash zone along 20S between New Caledonia and Queensland that will just get stronger all week. Avoid.

Checking out the Madden Julian Oscillations (MJO) indicates we need to wait another week or so for activity to start being on the increase – A new tropical cyclone is likely to form north of Darwin on Wednesday as this new MJO starts kicking in.

NEW ZEALAND: is a land of mobile fronts. The Highs are taking the equinoctial track (across Tasmania then fading in the northern Tasman Sea) and that’s about 3-weeks ahead of schedule. One front and its SW change should cross NZ on Monday/Tuesday, and the High following it should fade in the Tasman Sea. The next front and SW change coincides with a deepening system at 60S so that it can throw polar-chilled-southern-ocean-air onto NZ on Wed and Thu (that’ll take the chirp out of the cicada). The High following this front is expected to get over 1030 over Tasmania on Thursday and finally cross NZ in a weakened state Sun-Tue 5-7 March.

The terms used here are more fully explained in the METSERVICE Yacht Pack.
Feedback to mcdavitt@metservice.com - Bob McDavitt

[Euro Cruiser]

Southernman:

When cruising in SoPac, what's the typical way(s) to receive Bob's f'cast info when 'off the grid'. SSB Voice? Text file available for retrieval by e.g. Saildocs using the SSB? He's so highly regarded, yet it's not been clear to me how we access his f'cast updates.

Jack

[GordMay]

SoPac Weather Forecasts:

Weatherfax: The NZ MetService broadcasts weatherfaxes over five single-sideband radio frequencies: 3247.4, 5807, 9459, 13550.5, and 16340.1 kHz. The Tasman-New Zealand and the Southwest Pacific mean sea-level analysis charts are updated every six hours. The Southwest Pacific prognosis charts looking ahead 30, 48 and 72 hours are updated twice a day. The transmission schedule is broadcast between 11:00 and 11:45, sequentially at 15-minute intervals on the above frequencies. The schedule and faxes are also available on the MetService website. Satellite images are on the website as well.

Voice broadcasts: The High Seas Forecast is a human-voice broadcast that is updated twice a day and transmitted as follows: at 0903 and 2103 UTC on 6224 and 12356, and half an hour later at 0933 and 2133 UTC on 8297 and 16531. In addition, warnings are issued at 0303 and 0333 UTC and at 1503 and 1533 UTC on the above frequencies. The forecasts are divided into three areas:

A. The Pacific, from 170 degrees west to 120 degrees west between 25 degrees south and 55 degrees south.

B. The Subtropics, from 150 degrees east to 170 degrees west between 25 degrees south and 40 degrees south.

C. The Forties, from 150 degrees east to 170 degrees west between 40 degrees south and 55 degrees south.

New Zealand coastal-area forecasts are broadcast on VHF and on 2207, 4146 and 6224 at 0533, 1333 and 1733 NZ Standard Time and on VHF only at 0733 and 2133 NZST. The country is divided into 17 marine areas and each is covered in the forecast.

In addition, local forecasts are broadcast in some areas on VHF radio. In Auckland, continuous weather information is transmitted on VHF channel 21.

Weathergram: NZ MetService Weather Ambassador Bob McDavitt writes an informal weekly weathergram, specifically for voyagers, defining the major features driving weather in the Southwest Pacific. It is distributed via email. Subscribe on the Web through Yotreps at http://www.pangolin.co.nz/yotreps/index.asp, or directly from McDavitt at mcdavitt@metservice.co.nz

***

As posted on NoonSite:

From: Bob McDavitt, Weather Ambassador mcdavitt@metservice.com

The main area I watch is from French Polynesia to the Australian East coast (but I can do Galapagos to Marquesas if you ask). I do not offer routing information (waypoints and so forth) but I do offer Weathergrams and 5-day forecasts --

Weathergrams: I occasionally (usually on a Sunday) send my weather ideas for sailing around the South Pacific as email messages which I call weathergrams. Use these to plan when to start your voyages. You can log yourself on (and off) these (and/or yacht reports) from http://www.pangolin.co.nz/yotreps/list_manager.php

Bob McDavitt's most recent weathergram is at http://www.pangolin.co.nz/yotreps/po...Bob%20McDavitt's%20Weathergram's%20Weathergram

To receive a weathergram report by return email send an email, with a blank header and the word "weathergram" (without quotes) in the text body to yotreps@pangolin.co.nz. Alternatively, send an email to that address with the word "help" (no quotes) in the body for information on all available email services.The weathergram list is free.

MetService High Seas Forecasts are sent in English by ZLM on HF 6224 and 12356 at 0303Z, 0903Z, 1503Z and 2103Z and on 8297 and 16531 30 minutes later. Full details are in the Nautical Almanac or at http://www.hydro.linz.govt.nz/msi/me...broadcasts.pdf

MetService maps are sent by Radio Fax on ZKLF on SSB 3247.4, 5807, 9459, 13550.5 or 16340.1, Sked sent between 2300 and 2359Z and is at http://www.metservice.co.nz/services...x_schedule.asp

All the above is free in the public domain.

Other weather forecast information by email : From www.buoyweather.com for $10 you can get 100 messages, triggered by your own email, each giving a voyage forecast. Then there is pangolin@xtra.co.nz - send an email with the word HELP in the message and it will auto reply all its services. Sailmail and seamail also offer various weather packages.

Voyage forecasts (and weather watch/updates): When I'm available I can send you a weather forecast covering the next 5-days, by email or by fax (if sent by fax you get the weather maps). Forecast includes target pressures (my speciality). Cost is $NZ50 per forecast + any communication expenses, and $10 per 5 minutes for any extra weather updates. Let me know your Boat type and name and likely depature date, speed and destination (and credit card info) a few days before you intend to sail. You can split the credit card details over two emails or phone/fax to: Bob McDavitt, MetService Weather Ambassador, PO Box 68429, Newton, Auckland, New Zealand, mcdavitt@metservice.com Phone (+64 9) 377 4831 Fax (+64 9) 3075993

The Webfetch feature of sat phone email provider UUPlus does enable one to download the NZ Pacific weather fax charts over email. It takes about 1 minute, 20 seconds for a 15 kb chart; a cost of US$2.00 with Iridium, but very good quality of image.

[Euro Cruiser]

Gord, I think you missed mentioning when Bob has his 2nd cup of coffee; otherwise, that's a pretty comprehensive listing - thanks!

Jack

[GordMay]

Jack:
Sorry ‘bout that - don’t know Bob’s coffee schedule.
I hear that he wears “boxers”, not “briefs”, if that helps.
Gord