Bob Blog 2 May 2021

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 2 May

One weather app for your smart phone that I didn't mention last week, and is worth trying out is Luckgrib.com - it has been engineered for Apple devices but can be used on android devices (baixarapk.gratis/en/app/992336031/luckgrib). It has been optimised to download weather data on low bandwidth connections., supports iridium Go and RedPort Optimizer

REVIEW OF THE LAST MONTH (April 2021)
Sea Surface temperature anomalies Compared with a month ago:
La Nina has gone, and eastern equatorial Pacific is now near normal. The warm patch near West Australia has weakened. Everything else is much the same as last month.
The subtropical ridges in both hemispheres have grown during the past month, especially in southern Indian Ocean and across Australian Bight. The doldrums have shifted both west and east off Indonesia.
Pressure falls over the Arctic as spring arrives there. Swing from high to low pressures in north Atlantic and from neutral to low pressures over Tasman Sea / New Zealand area. The 1015 isobar has shrunk around and started to travel northwards across Australia as the continent cools inland as the nights get longer.
The seasonal weather pattern is on target for the end of the cyclone season in the Southern hemisphere.

The Tropics
There are some weak zones of potential development east of Philippines and between Vanuatu and Fiji.

WEATHER ZONES
SPCZ=South Pacific Convergence zone.
The SPCZ is expected to be weak and mainly north of Fiji and Samoa, and another branch from south of Fiji to Southern Cooks
A trough is expected to form between Queensland and New Caledonia this week. This may bring a weather pattern that is Ok for sailing from Australia eastwards.

Subtropical ridge (STR)
HIGH 1031hPa in the Tasman Sea weakening over northern NZ Mon to Wed.
Another HIGH in south Tasman Sea by wed developing to 1038hPa over and east of the South Island northeast-wards from Thurs to Sunday.
These highs are expected to make a squash zone of enhanced ESE winds on their northern side, mainly around 20S.

Aussie/Tasman/NZ troughs
Low is expected to form off NSW coast by mid-week and then travel off to the south.
Front with southerly change over Tasmania by Monday morning should reach southern NZ by late Tuesday and North Island by late Wednesday.

Panama to Galapagos/Marquesas
Light winds for Panama. SW winds from around 7N to 5N then southerly winds to Galapagos. Currents help make the trip via north of Galapagos better this 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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Contact is bob@metbob.com or txt 64277762212
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