Followers

Translator

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

26 September 2021

Bob Blog 26 Sep

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 26 Sept 2021
Equinox was as 7:20am NZ time on Thu 23 Sept. This marks the instant that
the overhead sun is directly over the equator, shifting from the northern
hemisphere to the southern hemisphere.
In New Zealand the change to NZDT Daylight time occurred at 2am this morning
(3am NZDT). The clocks sprung ahead an hour and so for us today is a 23hour
day.
The change to daylight saving occurs on different dates for the nations
around the South Pacific so I think it's a good idea for you to have a
summary for reference
Date Place Daylight saving time
zone
Sun 26 Sep New Zealand UTC+13 (NZDT)
Sun 26 Sep Chatham Islands UTC+13h45mins (CHADT)
Sun 3 Oct New South Wales, Tasmania UTC+11 (AEDT)
Note that Queensland, Western Aus and Northern Territory do NOT observe
Daylight saving.
Sun 3 Oct Lord Howe Is. UTC+11 (AEDT) (30 minute
ahead)
Sun 3 Oct Norfolk Island UTC+12 (AEDT)
Sun 14 Nov Fiji UTC+13 (Fiji Summer Time
FJST)
Note that Fiji reverts to standard time on Sun 16Jan 2022.
No changes in New Caledonia, Tonga or American Samoa or Vanuatu.
Samoa did have some daylight saving during the last few years but NONE
PLANNED this summer.

October is the month that yachts plan to leave the tropics for the
approaching South Pacific Cyclone Season, nominally on 1 November (starting
at low risk). Planning for departure from Fiji or French Polynesia is
complicated due to requirements for PCR Covid tests, etc. and so it is
useful to have a summary of the various national holidays for next few
months.

From East to west, LOCAL DATES
French Polynesia Mon 1 Nov All Saints Day, Thurs 11 Nov Armistice Day
Cook Islands: Tue26 Oct Gospel Day
Niue: Tue Oct 19 to Fri 22 Oct for Constitution Day celebrations, Fri 22Oct
is Gospel Day.
American Samoa Mon 11 Oct Columbus Day
Samoa Mon 11 Oct White Sunday (mondayised)
Tonga Thurs Nov 4 Constitution Day, Mon 6 Dec King Tupou I Day
Fiji Mon 11 Oct Fiji Day, Mon 18 Oct Prophet Mohammed's Birthday (starts in
evening),
Thu 4 Nov Diwali.
Vanuatu Tue 5 Oct Constitution Day, Mon 29 Nov National Unity Day
New Caledonia Mon 1 Nov All Saints Day, Thurs 11 Nov Armistice Day.
New Zealand Mon 25 Oct Labour Day.
Australia: Mon 4 OCT Labour Day (ACT, NSW &SA), Queen's Birthday (QLD)

TROPICS
Cyclone PETER faded near Bermuda and then TERESA rose from its remnants.
SAM seems have more strength than PETER/TERESA but should stay offshore.
MINDULLE may well sideswipe eastern Japan this week.
GULAB is expected to fade over Northeastern India.

WEATHER ZONES
SPCZ=South Pacific Convergence zone.
The SPCZ is expected to more active than last week, and slowly shift south
onto Fiji mid-week then drift north again.
Low south of southern Cooks tonight is expected to peel off to the southeast
by mid=week and associated trough may cross Tahiti around mid-week.
Trough associated with L3 is expected to travel eastwards across northern
Tasman Sea late in the week and reach New Caledonia by the weekend.
HIGHS and LOWS
LOW1 is a complex low south of Southern Cooks that should fade as it moves
SE.
HIGH1 starts the week east of NZ and should intensify as it tracks to the
southeast.
LOW2 is expected to form off the North Island East Coast on Monday and
deepen to below 995 neat Chatham Island by Wed then weaken as it goes off to
the southeast.
HIGH2 over 1025 tonight is expected to travel northeast across the Tasman
Sea and the eastwards along 35S across northern NZ and can be used to sail
west or east across the Tasman Sea.
LOW3 is expected to move off New South Wales from Thursday and deepen in
central Tasman Sea this weekend and may then travel northeast onto Northland
early next week. Avoid.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more detail for 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 txt 64277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

19 September 2021

Bob Blog 19 Sep

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 19 Sept 2021

SUCKERS and PUFFERS

Can you tell the difference between a sucker cloud and a puffer cloud?

Clouds that grow upwards into the sky are called cumulus clouds. They start
off as fluffy white ones.
Once they get sufficiently tall they produce a shower of rain.

If conditions are strongly unstable this shower may become heavy, perhaps
with hail, or thundery or squally.

These small cumulus clouds can be called suckers because that have a zone of
calm on their leading edge. As a sucker approaches the wind speed gradually
drops away. When you see these clouds, try and sail around and between them
rather than under them.

As you look into the surface wind, the cloud will creep to your right (in
the southern hemisphere). This is because it is propelled by the stronger
upper winds. Friction causes the surface wind to "leak to low pressure" and
be to be to the left of the winds aloft. When sailing upwind, put the wind
to starboard (go left) to avoid the approaching calm, and aim for the LEFT
edge of the cloud to catch the extra winds on its rear.

The taller clouds can be called puffers. Once the turrets grow to be taller
than their base, they can start producing rain in the colder upper region,
this rain falls and drags with it a downdraft that fans out from the back
end of the cloud like a waterfall.

As the downdraft ahead of a puffer reaches you, surface winds suddenly
increases. There is a direction-shift around the shoulders of the cloud, and
a huge calm zone that trails behind it. When sailing upwind into an
approaching puffer, remember to do the "squall checklist" --- put things
away-reef the rig--- check the compass-and watch the wind on the water
ahead. When the first puff of the downdraft appears, put the wind on
starboard (go left) so that we are sailing away from the puffer. We may get
lifted for a few minutes as we go around the shoulder of the cloud but keep
aiming to the left so we avoid being caught in the trailing calm zone.

TROPICS
Cyclone PETER is expected to peel off to the northeast and may swipe past
Bermuda.

WEATHER ZONES
SPCZ=South Pacific Convergence zone.
The SPCZ stretches from Solomona to Tuvalu to Samoa to Southern Cooks, in
its normal position.
Trough over Niue to Southern Cooks tonight expected to get onto French
Polynesia by mid-week and form a low that travels off to the south by end of
the week.
Trough reaching New Caledonia by mid-week is expected to reach Tonga/Niue
area by end of week.

HIGHS and LOWS
HIGH1 above 1024 to north of NZ is moving ESE along 30 to 35S followed by H2
travelling along 30S. This maintains useful trade winds this week north of
15S.
LOW1 is expected to form near Lord Howe by Tuesday and deepen to 995 as it
crosses central NZ on Wed/Thursday/by Wednesday in mid Tasman. Avoid.
Associated trough may form new low east of North Island and south of Niue by
end of week.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more detail for 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 txt 64277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

12 September 2021

Bob Blog 12 Sep

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 12 Sept 2021

La Nina may be coming back

What is a La Nina?
When the Pacific trade winds are stronger-than-normal they drag sun-warmed
sea surface to the west, encouraging upwelling of cooler deeper water around
the Galapagos. This can go on for months and is called a "La Nina" episode.
It shifts the subtropical ridge away from the equator.

The reverse of this, with less trade winds and warmer-than-normal seas
around the Galapagos, is called "El Nino". The comings and goings of these
episodes can last several months, maybe over a year, and so their status can
be used to help forecast the weather for the coming season.

The Ocean:
The sea surface temperatures in the equatorial eastern Pacific are
near-normal, but there is a zone of cooler-than-normal sub-surface water
that indicates conditions are starting to edge towards La Nina.

The Atmosphere:
ENSO = El Nino/Southern Oscillation. The Southern Oscillation Index SOI (30
day running mean) sums up the whole weather pattern over the South Pacific
into one number. It is based on the standardized difference in the barometer
readings between Tahiti and Darwin, in other words it counts the average
number of isobars between them on the weather map. When the SOI is more than
plus one(standard deviation from its mean) for more than a month we call it
a LA NINA event, and when it stays more than minus one we call it an EL NINO
event. These graphs from longpaddock.qld.gov.au multiply the SOI by 10, and
show a LANINA episode (>10) from Nov 2020 to Feb 2021, then near-zero March
to June then a strong positive swing in July and a relaxation in August.
There has been a positive swing so far in September.

The NCEP CFSv 2 and North American Multi-Model Ensemble show that a weak LA
NINA is likely in the next few months with a 70-80% chance of La Nina from
Oct 2021 to Feb 2022.
So we seem to be on the edge of a new La Nina. At this time of the year the
Tasman Sea / NZ area is having its usual spring weather pattern with a ridge
/trough cycle and strong NW and SW winds, with each trough followed by a
burst of SW swell reaching into the subtropics. If this La Nina clicks in as
forecast then these troughs may weaken and shift south bringing this area an
early start to summer-type conditions. NZ's climate agency NIWA is
forecasting larger than normal HIGH pressure systems about and east of NZ
for the next few months, and this is consistent with an incoming La Nina.

TROPICS
CONSON and CHANCHU (Kiko) formed over the Philippines. CHANCHU as Cat 5 for
a while and is now travelling northwards off Taiwan and heading for
Shanghai.

WEATHER ZONES
SPCZ=South Pacific Convergence zone.
The SPCZ stretches from Solomona to Tuvalu to Samoa to Southern Cooks.
Trough to north of L1 is expected to reach New Cal by Wednesday and Tonga
area by Saturday.

HIGHS and LOWS
HIGH1 above 1024 to NE of NZ is moving ESE along 30 to 40S followed by H3
travelling along 30S. this maintains useful trade winds this week between
Tahiti and Niue.

LOW1 is expected to form offshore of Coffs by Tuesday and deepen to 995 by
Wednesday in mid Tasman then travel ESE and weaken east of Northland by
Saturday. Avoid.

LOW2 below 970hPa at 55S is bringing a NW gale to Canterbury tonight and
its trough is travelling east of NZ next few days.

HIGH2 over 1024 over Tasmania by Wednesday is expected to cross the South
Tasman and get east of the South Island by Saturday, combining like an
eggbeater to produce a vigorous SE flow over eastern North Island and thru
Cook Strait.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more detail for 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 txt 64277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

07 September 2021

Advanced SEO plans

Off the shell SEO plans to increase your website`s SEO Metrics and Ranks
within just 1 month

See more details here
https://liftmyrank.co/affordable-seo-services-small-businesses/





Unsubscribe:
please send a blank email to RonaldLilly7162@gmail.com
you will be automatically unsubscribed

05 September 2021

Bob Blog 5 sept

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 05 September 2021

REVIEW OF THE LAST MONTH (August 2021)
SST: The warming trend in North Pacific shifted northwards during August
from Japan to the Aleutians, with a warm pool lingering north of Hawaii.
There as some cooling around the eastern equatorial Pacific but not enough
to form a LA NINA. Not much change in the Southern Hemisphere.

ISOBARS: The northern subtropical ridge has weakened and gone south in the
Atlantic. In the southern hemisphere the subtropical ridge has weakened in
the Indian Ocean but intensified and gone south over Australia and NZ. The
Antarctic HIGH has weakened.

In a reversal of July's anomolies, pressures in August were ABOVE NORMAL
over Tasman Sea/NZ, central south Atlantic and south of Japan. August also
brought more lows than normal to Canada and western North America.

Zooming into the NZ area
Over the Tasman Sea, despite the higher valued isobars the pressure
gradient/wind flow is much the same as last month. The seasonal outlook is
for more westerly winds in the coming months.

TROPICS
Hurricane IDA took a damaging track across USA with a death toll of near 60
and flash flooding in New York.
LARRY is in mid north Atlantic and should peel off to the northeast, but its
remnants may sideswipe Novia Scotia.

WEATHER ZONES
SPCZ=South Pacific Convergence zone.
Part of the SPCZ is over Fiji tonight and travelling southeast where it
should form a low near 25S by Tuesday.
Otherwise, the SPCZ this week stretches from Solomona to Tuvalu to Samoa.

HIGHS and LOWS
HIGH over 1030 east of NZ expected to travel east along 35 to 40S with a
squash zone of enhanced easterly to northeasterly winds near 25 to 30S.
LOW below 1005 in southwestern Tasman Sea tonight and associated trough
expected to cross NZ on Mon/Tues followed by vigorous westerly flow then
another trough on Friday, followed by SW flow on Saturday.
HIGH 1030 expected by Thursday to travel east into northern Tasman Sea along
30S south passing north of NZ of NZ on Friday.
Lookout for a deepening LOW to form in Tasman Sea on 12 Sept and cross
northern NZ on 13-14 Sep. Avoid.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more detail for 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 txt 64277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Blog Archive