Followers

Translator

WEATHERGRAM

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

17 March 2024

Bob blog 17 March

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 17 March 2024

EL NINO fading to NEUTRAL,

In mid-March the equatorial current was going westwards as if on
steroids.

As the surface: warm water is being pushed physically by an increasing
wind from the east Pacific along the equator. This happens across the
entire equatorial Pacific and piles up over the western Pacific.
There, to flatten out this buildup, water beneath it at around 50 to
150m is pushed outwards at over 2kt, creating an east-going current
called the Pacific Equatorial Undercurrent or EUC which starts in
Indonesia.

When this current hits the barrier offered by the Galapagos, most of
it diverts around this obstacle, but some of it diverts upwards to
replace the water that has been taken west-wards. This UPWELLING,
being cooler and full of nutrients, provides the rich animal and bird
life of the Galapagos with a feast of food.

The behaviour of the EUC is tied up with the El Nino and La Nina
patterns, but because it is hard to observe, little is known what
changes its 'mood".

We do know a lot now about how the tropics influence New Zealand
weather. Ove the recent summer ELNINO was in the driving seat,
producing more westerly winds than normal over NZ - filling the hydro
lakes with reasonable rain, but producing dry conditions east of the
Alps, and now a drought in Marlborough. During autumn EL NINO will be
replaced by what we call "NEUTRAL" conditions. The weather will swing
from one pattern to another, allowing variety as each pattern gets to
"play" for a short time. I call this "Weather Jazz"
(youtube.com/watch?v=dlee09qmnv4)

TUVALU is slowly sinking
The spring tide in February is always higher than other months because
of the season. This year, with the warmer than normal seas in the
ocean, the February spring tide brought flooding to Funafuti's main
road. The newly elected Government have a hard time on their hands
with just a few decades left to shift the whole population somewhere
else.



TROPICS
Tropical Storm Filipo brought much needed rainfall to southern
Mozambique after forming over the Mozambique Channel. Cyclone Meagan,
named yesterday, is heading west almost towards Darwin. Tropical
depression Eighteen is lurking off NW Australia and also travelling
westwards.

The MJO pattern is now active over Northern Australia and moving into
the Pacific, increasing the risk of cyclone formation on the Coral sea
over the coming week.

WEATHER ZONES
The South Pacific Convergence zone is very active this week across the
Coral Sea and Vanuatu to Fiji and then east-southeastwards to the
Austral Islands.

Tropical Low L1 now west of Vanuatu is expected to slowly travel SE
over southern parts of Fiji later this weekend. Avoid.

HIGHS and LOWS

LOW L2 south of Niue is expected to travel slowly southeast.

Low L3 just east of Chathams tonight is expected to go northeast and
deepen in the next few days, then turn east and then southeast
following L1. Avoid.

HIGH H1 in the Tasman Sea is expected and the North Island on Friday,
followed by a northerly flow ahead of L4 which should reach mainly the
North Island on Friday.

Panama to Marquesas:

The northerly winds in Panama gulf are becoming less reliable as the
equinox approaches.

Avoid departing between 21 and 29 March.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about your voyage, then check
metbob.com to see what I offer.
Or Facebook at /www.facebook.com/metbobnz/
Weathergram with graphics is at metbob.wordpress.com
(subscribe/unsubscribe at bottom).
Weathergram archive (with translator) is at
weathergram.blogspot.co.nz.
Contact is bob@metbob.com or text 64277762212.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Blog Archive