Bob Blog 24 May



Compiled Sun 24 May 2020

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.


The Tropics

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

It was a busy week last week, with AMPHAN hitting NE India and Bangladesh hard , and an early Atlantic storm ARTHUR affecting eastern USA. Now MANGGA is threating Perth, Australia.



Weather Zones (see text) as expected Wednesday 00UTC showing isobars, winds, waves(magenta), Rain (Blue), CAPE (pink), STR, and SPCZ.)


SPCZ=South Pacific Convergence zone.

The SPCZ is active around Solomon Island, building this week to north of Vanuatu and to N of Fiji, and then rather weak from Samoa to Tuamotu Islands.

A TROUGH may form around Fiji early next week.

Accumulated rainfall for next week from (isobars are for Sunday night).


Subtropical ridge (STR)

HIGH 1025-1028hPa is expected over Tasmanian on Monday, and should cross central and southern NZ on Thurs

Next HIGH 1028hPa is expected to cross Tasmania on Thurs and cross southern NZ on Friday and then build to 1036hPa well east of NZ.

Tasman Sea /NZ/Aus

A low is expected to cross northern and central NZ on Mon and then deepen to 950 hPa well off the SE of NZ, with up to 10m swells offshore.

Another low in the north Tasman Sea may bring wind and rain to northern NZ this weekend and Mon next week.

From Panama:

Not good this week, and maybe for the coming months. SW winds have arrived in Panama, and, although reasonably clear tonight, the ITCZ visits at times. It is most active/squally between 6 and 3N. I reckon that the best way to tackle these SW winds is to go SSE then west.


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