Bob Blog 18 Dec

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 18 December 2022
GOOD OLD SCOTTISH ENGINEERING

To measure the air temperature, we need to put a thermometer in equilibrium
with an air sample. The air sample should be well shaded from sunlight but
in a box that is well ventilated with fresh air. Such a box was first
designed by Thomas Stevenson as reported in the June 1864 edition of the
Journal of the Scottish Meteorological Society. I wonder if the louvre
system was inspired by a Christmas Tree,

Thomas Stevenson spent his whole life in Edinburgh and watching waves around
the surrounding coast. His observations are written here
babel.hathitrust.org/cgi/pt?id=uc1.b4525127&view=1up&seq=54
stating that wave height =1.5 times square root of fetch.

He and his brothers Alan and David made great advances in the engineering
of electrifying LIGHTHOUSES. His brother-in-law, James Balfour, went to New
Zealand and became the first Marine engineer for Otago Province.
His youngest son, Robert Louis Stevenson, didn't follow in his father's
footsteps. Instead, he became a novelist and world traveller rather than an
engineer. Thomas was not amused.


TROPICS
There is a zone of potential development in the Indian ocean and around
Indonesia.
MJO
Over Christmas and New Year the active part of the MJO is expected to travel
from Indian Ocean to NW Australia.
In the New Year there is an increasing chance of a cyclone forming in the
Coral sea area,

WEATHER ZONES
South Pacific Convergence zone
The SPCZ is expected to have an active week across the Coral Sea to north
of Fiji , and over Samoa to east of Tonga. Another convergence zone is
expected to linger about and south of French Polynesia. An active trough is
expected to cross New Caledonia around mid-week. Avoid.

HIGHS and LOWS
HIGH H1 south of Tahiti is expected to travel slowly off to the northeast
this week.
This allows room for Low L1 now in the Tasman Sea to cross central NZ on
Thursday and Friday, followed by a weak ridge over the Christmas weekend
Low L2 is expected to travel across New South Wales late this week and into
the Tasman Sea this weekend and linger there until next week.
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If you would like more detail for your voyage, then check metbob.com to see
what I offer.
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at bottom).
Weathergram archive (with translator) is at weathergram.blogspot.co.nz.
Contact is bob@metbob.com or txt 64277762212
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