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

03 February 2013

BOBGRAM issued 3 Feb 2013

Issued 3 Feb 2013

Ap0logises for any multiple resends--- problems with email server tonight.
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 of weather maps, so please fine-tune to your place. Dates are in UTC unless otherwise stated.
The Atmosphere: The Southern Oscillation Index or SOI (30 day running mean) dived to almost minus 1 during December, and relaxed to near zero during January. Around 3 Feb it was minus 0.4 .

The Ocean: Sea surface temperatures across the equatorial Pacific act as a thermostat for the planetary weather engine. When they are different from normal we get a change in clouds around the equator and thus changes the earthly wind zones and has an impact on the latitude zones of weather across the whole Pacific.
Well, in the past month the SST in this target zone has mostly been around normal, and so the oceanic pattern is neither El Nino, nor La Nina; it remains neutral.

The remains of OSWALD have moved off eastern Australia now and the flooding has gone. Interestingly, the clouds and rain over Indonesia have mostly gone too. Good riddance.
This coming week is usually the hottest week of the year in the mid-latitudes of the Southern hemisphere, and Australia is acting as a hot plate left out in the sun. There is NOT expected to be any relief from any monsoonal trough (except maybe over NW Australia)… just more mainly East to NE winds until at least mid-February.
The South Pacific Convergence Zone SPCZ is it its northern position from Solomons to French Polynesia , however there is also a more southern zone with a tropical depression near Fiji extending clouds onto Niue and Southern Cooks. The westerly winds on the northern side of this low are expected to increase, and the low may well turn into a TC. Anyway its future track is expected to go ENE across Tonga on Monday and then East and the SE across Southern Cooks on Wednesday 6 Feb. Avoid.

The Sub tropical ridge STR extends from Aussie Bight to north of NZ to east of NZ. During the coming week that high cell now in the Aussie Bight is expected to drift east and cro9ss central NZ on 6 to 8 February, just in time for picnic weather for WAITANGI DAY. "Positive Vibration" would have said/song Bob Marley (6 Feb= his birthday; ALSO still celebrated in NZ). – we can celebrate an end to blocking with a little music, yea.

OK there are two troughs form NZ this week, after a record dry January is many parts of the country (

One trough is expected to cross on Mon/Tue but has to combat dry air and may not make much impact. The next trough is expected on Sun/Mon/Tue 10-12 Feb and should be able to bring more rain to our parched pastures.
See my yotpak at for terms used.
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