Bob Blog 13 June

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.

Compiled Sunday 13 June

First, a reminder that Gulf harbour radio GHR , a coastal radio station ZMH286, run by Patricia and David, is now operating on 8752kHz or 8779kHz or 8297kHz , in that order depending on interference at (the new COVID time) 0515 UTC (1715 NZST) Monday to Friday. From 7 June they have their live streaming service running at with a backlist of previous seasons.

Second, those new links for the Weather Maps that I included in last week’s blog got mangled by my blog editor, so here they are again.

These are courtesy of Max from, to use anyone of them send an email to, no subject needed, with message SEND and then the link of your choice:

Weather Map coming from Fiji Met Service:
–> 3AM FST Surface Map available daily from 05.00am Fiji time
–> 6AM FST Surface Map available daily from 09.30am Fiji time
–> 09AM FST Surface Map available daily from 11.00am Fiji time
–> 12PM FST Surface Map available daily from 03.00pm Fiji time
–> 03PM FST Surface Map available daily from 05.00pm Fiji time
–> 06PM FST Surface Map available daily from 08.30pm Fiji time
–> 12AM FST Surface Map available daily from 03.00am Fiji time

Weather Map from New Zealand Met Service update every 6 hours, normally at 02-08-14-20 UTC TIME:
–> Last Analysis Pressure chart Actual time
–> +30 hours pressure forecast chart
–> +48 hours pressure forecast chart
–> +72 hours pressure forecast chart

Thirdly, that LOW last week over Victoria, Australia, which brought wide-spread damage from wind and rain was a polar blast, with cold air being shovelled into the back of the LOW thanks to a HIGH well south of the Australian Bight:


Satellite imagery from on Tuesday 9 June.

The Tropics

The latest cyclone activity report is at and Tropical Cyclone Potential is from

Storm KOGUMA wakened when it made land fall in Vietnam today. TC CARLOS has formed (today) in the East North Pacific. There is still a moderate zone of potential development off the southwest of Mexico.



Weather Zones Mid-week GFS model showing isobars, winds, waves(magenta), Rain (Blue),

STR (Subtropical Ridge), SPCZ (South Pacific Convergence Zone) and CAPE9 (in pink)


CAPE mid-week as seen by ECMWF and GFS from


SPCZ=South Pacific Convergence zone.

The SPCZ is expected to be rather thin and weak, stretching from Solomon Islands across Coral Sea to Samoa.

A trough over New Caledonia on Monday is expected to travel west and reach Fiji/Tonga by mid-week and Southern Cooks by end of the week.

Another passing trough is expected to reach New Caledonia by end of the week.

These troughs offer an opportunity for yachts wanting to go east, and a challenge for those going west.


Rain Accumulation next five days from

Subtropical ridge (STR)

HIGH 1030 east of NZ is travelling east along 35S. It has a squash zone of enhanced trade winds on its northern side that will also travel east.

HIGH 1020 is expected to form in the northern Tasman Sea by Wednesday and travel east past the north of North Island by Saturday.

Another HIGH 1020 is expected to travel northeast out of the Southern Ocean from Monday and get southeast of South Island by Friday, feeding chilly air onto South Island on Tuesday and Wednesday.

Aussie/Tasman/NZ troughs

LOW 1004 tonight to east of Tasmania is expected to travel east across the South Island on Monday/Tuesday

Another low 1002 is expected to deepen to northeast of Tasmania on Thursday and travel northeast reaching North Island by Sunday 20 June.

Typical trough/ridge inter pattern with a nearly weekly rhythm.


If you would like more detail for your voyage, then check to see what I offer.

Or Facebook at /

Weathergram with graphics is at (subscribe/unsubscribe at bottom).

Weathergram archive (with translator) is at

Contact is or txt 64277762212


Published by metbob

Pattern and Chaos

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