Bob Blog 25 Dec 2022.
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 25 December 2022
FESTIVE GREETINGS EVERONE
Whilst the world media concentrate on the polar blast across North America
this Christmas
(www.theguardian.com/us-news/2022/dec/21/us-winter-weather-storm-cold-snap).
.
Cyclone DARIAN was named last week and is still traveling SE across the
Indian Ocean to SW of Jakarta.
It did a loop and intensified to Cat 5 on the Australian scale and Cat 4 on
the Saffir-Simpson hurricane wind system scale.
In the past few days another cyclone flared briefly. On Thursday it was
named ELLIE as Cat 1 off Darwin.
This reminded us of Cyclone TRACY that hit Darwin at Christmas 48 years ago
in 1974.
ELLIE made landfall as a Cat 1 system. It did NOT have enough time to grow
as much as TRACY over the open ocean,
however even as a CAT 1 system it has been very wet and did do some damage.
See
www.news.com.au/technology/environment/tropical-cyclone-ellie-declared-set-t
o-make-landfall-as-category-1-storm/news-story/b38bb5009b308ee695467dab2e002
16e
and
www.abc.net.au/news/2022-12-24/cyclone-ellie-displaces-homeless-residents/10
1806274
Ex-ELLIE moved inland on Christmas eve as seen at
www.bom.gov.au/australia/meteye/
In the map above there is a HIGH shown in the Aussie Bight, south of ELLIE.
This is travelling east and should build in the Tasman Sea on Boxing Day
making gusty NE winds for a quick start to this year's SYDNEY-HOBART yacht
race.
The tailenders are expected to encounter a passing trough on Wednesday
See
rolexsydneyhobart.com/news/2022/pre-race/2022-rolex-sydney-hobart-fleet-set-
for-downwind-start/
The tracker for the race is at www.rolexsydneyhobart.com/tracker/
MJO
The active part of the MJO is now travelling across Indonesia and north
Australia.
In the New Year there is an increasing chance of a cyclone forming in the
Coral sea area,
WEATHER ZONES
South Pacific Convergence Zone
The SPCZ is expected to have an active week across the Coral Sea to Fiji and
to the southeast.
A tropical low is expected to form in the Coral Sea by mid-week and then
travel SSW into the western Tasman Sea by end of the week.
HIGHS and LOWS
HIGH H1 building in Tasman Sea on Boxing Day and is then expected to travel
east across central Aotearoa NZ this week and then travel east along 40S.
After a month or so of passing troughs this is summer "coming at last" over
Kiwi land.
As usual this is a High between two lows.. L1 is expected to form between
Tonga and NZ on Boxing Day then travel southeast and peak in development
mid-week and then get steered to the SW as H1 travels east. Surfs up for
East coast North Island around New Years.
Low L2 is expected to form in the Coral Sea by mi- week and then travel
south towards Lord Howe by end of the week.
L2 may interfere with trans-Tasman sailing this 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
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
24 December 2022
18 December 2022
Bob Blog 18 Dec
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 18 December 2022
GOOD OLD SCOTTISH ENGINEERING
To measure the air temperature, we need to put a thermometer in equilibrium
with an air sample. The air sample should be well shaded from sunlight but
in a box that is well ventilated with fresh air. Such a box was first
designed by Thomas Stevenson as reported in the June 1864 edition of the
Journal of the Scottish Meteorological Society. I wonder if the louvre
system was inspired by a Christmas Tree,
Thomas Stevenson spent his whole life in Edinburgh and watching waves around
the surrounding coast. His observations are written here
babel.hathitrust.org/cgi/pt?id=uc1.b4525127&view=1up&seq=54
stating that wave height =1.5 times square root of fetch.
He and his brothers Alan and David made great advances in the engineering
of electrifying LIGHTHOUSES. His brother-in-law, James Balfour, went to New
Zealand and became the first Marine engineer for Otago Province.
His youngest son, Robert Louis Stevenson, didn't follow in his father's
footsteps. Instead, he became a novelist and world traveller rather than an
engineer. Thomas was not amused.
TROPICS
There is a zone of potential development in the Indian ocean and around
Indonesia.
MJO
Over Christmas and New Year the active part of the MJO is expected to travel
from Indian Ocean to NW Australia.
In the New Year there is an increasing chance of a cyclone forming in the
Coral sea area,
WEATHER ZONES
South Pacific Convergence zone
The SPCZ is expected to have an active week across the Coral Sea to north
of Fiji , and over Samoa to east of Tonga. Another convergence zone is
expected to linger about and south of French Polynesia. An active trough is
expected to cross New Caledonia around mid-week. Avoid.
HIGHS and LOWS
HIGH H1 south of Tahiti is expected to travel slowly off to the northeast
this week.
This allows room for Low L1 now in the Tasman Sea to cross central NZ on
Thursday and Friday, followed by a weak ridge over the Christmas weekend
Low L2 is expected to travel across New South Wales late this week and into
the Tasman Sea this weekend and linger there until next 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
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the
patterned world.
Compiled Sunday 18 December 2022
GOOD OLD SCOTTISH ENGINEERING
To measure the air temperature, we need to put a thermometer in equilibrium
with an air sample. The air sample should be well shaded from sunlight but
in a box that is well ventilated with fresh air. Such a box was first
designed by Thomas Stevenson as reported in the June 1864 edition of the
Journal of the Scottish Meteorological Society. I wonder if the louvre
system was inspired by a Christmas Tree,
Thomas Stevenson spent his whole life in Edinburgh and watching waves around
the surrounding coast. His observations are written here
babel.hathitrust.org/cgi/pt?id=uc1.b4525127&view=1up&seq=54
stating that wave height =1.5 times square root of fetch.
He and his brothers Alan and David made great advances in the engineering
of electrifying LIGHTHOUSES. His brother-in-law, James Balfour, went to New
Zealand and became the first Marine engineer for Otago Province.
His youngest son, Robert Louis Stevenson, didn't follow in his father's
footsteps. Instead, he became a novelist and world traveller rather than an
engineer. Thomas was not amused.
TROPICS
There is a zone of potential development in the Indian ocean and around
Indonesia.
MJO
Over Christmas and New Year the active part of the MJO is expected to travel
from Indian Ocean to NW Australia.
In the New Year there is an increasing chance of a cyclone forming in the
Coral sea area,
WEATHER ZONES
South Pacific Convergence zone
The SPCZ is expected to have an active week across the Coral Sea to north
of Fiji , and over Samoa to east of Tonga. Another convergence zone is
expected to linger about and south of French Polynesia. An active trough is
expected to cross New Caledonia around mid-week. Avoid.
HIGHS and LOWS
HIGH H1 south of Tahiti is expected to travel slowly off to the northeast
this week.
This allows room for Low L1 now in the Tasman Sea to cross central NZ on
Thursday and Friday, followed by a weak ridge over the Christmas weekend
Low L2 is expected to travel across New South Wales late this week and into
the Tasman Sea this weekend and linger there until next 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
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
11 December 2022
Bob Blog 11 Dec
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 11 December 2022
CONGRATULATIONS TO TOM ROBINSON
Tom Robinson is in the process of rowing across the Pacific Ocean and
yesterday made landfall in Penrhyn, Northern Cooks,
completing over half the trip. He hopes to be the youngest ever to row the
whole way solo. We wish him good speed for 2023.
MAKE YOUR OWN WAVES
This week I was introduced to an interesting " indoor ocean" wave-making
pool at youtu.be/pir_muTzYM8
How do they compute the virtual waves in movies and video games?
The answer is Fast Fourier Transforms and Oceanographic Spectra. To give you
a taste of this complicated topic
see the you tube at www.youtube.com/watch?v=kGEqaX4Y4bQ
And you can experiment with you own wave maker with a Google Play app at
play.google.com/store/apps/details?id=com.SimulationisEvolution.OceanWavesSi
mulation&hl=en_NZ&gl=US
TROPICS
Tropical depression Twenty Nine is moving away from Philippines. There is a
zone of potential development near Fiji.
MJO
The GFS ensemble outlook for the remainder of December shows enhanced
convection of the MJO is expected to build in the Indian Ocean.
This may point to a late start to the South Pacific Cyclone season.
WEATHER ZONES
South Pacific Convergence Zone SPCZ
The SPCZ is expected to have a very active week all the way from Solomona
Islands and especially active from Samoa to Southern Cooks.
One tropical Low L1 is tonight near southern Tonga and expected to go
southwest peak close to the NE of Aotearoa NZ by mid-week and then go
southeast and fade.
HIGHS and LOWS
HIGH over 1032hPa to east of NZ and south of Tahiti tonight is expected to
travel off to the east and be replaced by H1 from the southwest . These
highs are keeping a northeast flow from the subtropics onto NZ.
Low L2 is expected to travel across Tasmania on Monday and go southeast into
the South Tasman Sea, followed by another low that deepens in the Tasman on
Wed/Thursday and then crosses central NZ early next week.
Tropical low L3 is expected to form around the southern Cooks by mid-week
and then go SW /S/SE and finally push H1 off to the east, signalling a
change in pattern.
There may be a reasonable voyage from Fiji/Tonga to NZ after mid-week. If
trying to cross the Tasman be ready to divert around the fronts.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the
patterned world.
Compiled Sunday 11 December 2022
CONGRATULATIONS TO TOM ROBINSON
Tom Robinson is in the process of rowing across the Pacific Ocean and
yesterday made landfall in Penrhyn, Northern Cooks,
completing over half the trip. He hopes to be the youngest ever to row the
whole way solo. We wish him good speed for 2023.
MAKE YOUR OWN WAVES
This week I was introduced to an interesting " indoor ocean" wave-making
pool at youtu.be/pir_muTzYM8
How do they compute the virtual waves in movies and video games?
The answer is Fast Fourier Transforms and Oceanographic Spectra. To give you
a taste of this complicated topic
see the you tube at www.youtube.com/watch?v=kGEqaX4Y4bQ
And you can experiment with you own wave maker with a Google Play app at
play.google.com/store/apps/details?id=com.SimulationisEvolution.OceanWavesSi
mulation&hl=en_NZ&gl=US
TROPICS
Tropical depression Twenty Nine is moving away from Philippines. There is a
zone of potential development near Fiji.
MJO
The GFS ensemble outlook for the remainder of December shows enhanced
convection of the MJO is expected to build in the Indian Ocean.
This may point to a late start to the South Pacific Cyclone season.
WEATHER ZONES
South Pacific Convergence Zone SPCZ
The SPCZ is expected to have a very active week all the way from Solomona
Islands and especially active from Samoa to Southern Cooks.
One tropical Low L1 is tonight near southern Tonga and expected to go
southwest peak close to the NE of Aotearoa NZ by mid-week and then go
southeast and fade.
HIGHS and LOWS
HIGH over 1032hPa to east of NZ and south of Tahiti tonight is expected to
travel off to the east and be replaced by H1 from the southwest . These
highs are keeping a northeast flow from the subtropics onto NZ.
Low L2 is expected to travel across Tasmania on Monday and go southeast into
the South Tasman Sea, followed by another low that deepens in the Tasman on
Wed/Thursday and then crosses central NZ early next week.
Tropical low L3 is expected to form around the southern Cooks by mid-week
and then go SW /S/SE and finally push H1 off to the east, signalling a
change in pattern.
There may be a reasonable voyage from Fiji/Tonga to NZ after mid-week. If
trying to cross the Tasman be ready to divert around the fronts.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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
<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
04 December 2022
Bob Blog
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 4 December 2022
THE ISOBARS OF NOVEMBER
REVIEW OF THE LAST MONTH (November 2022)
Here is a link to a YouTube clip giving an animated loop of the isobars and
streamlines in the South pacific at youtu.be/qgPsVkd_U5U
Sea Surface temperature anomalies from psl.noaa.gov/map/clim/sst.shtml
The main pattern remains the same as since winter with the cool waters of La
Nina along the Eastern Equatorial Pacific surrounded by zones of warmer than
normal conditions in the north and south Pacific. The hot area that was off
Japan has relaxed. The rains over eastern Australian have run off and
produced a cool pool in the western Tasman sea .
Average isobars for past month
The Antarctic High has continued to weaken and thereby weakening the
southern polar vortex. The Artic low has almost disappeared. The southern
Subtropical ridge has noticeably weakened , except in the South Atlantic.
Pressure anomolies for past month
The lows that started over south Australia is early spring extended to NZ by
late spring. Rising pressures over the Aleutians and Canada and another zone
over northwest Europe is making the northern hemisphere a 2-wave pattern.
The Southern hemisphere is clearly in a 3-wave mode.
Zooming into the NZ area
On the tropical side the 1010 has drifted south onto northern Australia,
typical of summer. However, on the southern side the 1010 has shifted north
from Campbell Island to Taupo, due to the numerous lows and lack of highs
travelling across the Tasman Sea. This is more like a spring pattern.
TROPICS
There are no named storms at present. There is a zone of potential
development north of New Guinea.
WEATHER ZONES
The SPCZ is active at present in the eastern Coral Sea/Vanuatu/ New
Caledonia area but this should clear off to the southeast . Convergence zone
has cleared off French Polynesia at present. A Convergence zone now near
Samoa is expected to drift southeast to Southern cooks.
HIGHS and LOWS
HIGH H1 over North Island is expected to travel off to the east along 35S,
with a squash zone on its northern side around 27S.
Low L1 south of NZ is expected to travel east along 50S.
Low L2 is forming west of New Caledonia and expected to travel SE and fade
near Northland on Wed/Thurs, followed by H2.
Low L3 is expected to travel slowly Se from Bass strait into the south
Tasman Sea by mid-week and then Northeast towards central NZ by end of week.
HIGH H3 should banana around south side of L3 and build east of the South
Island by end of the week.
Looking Ok to sail to NZ next ten days, just divert around the lows.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the
patterned world.
Compiled Sunday 4 December 2022
THE ISOBARS OF NOVEMBER
REVIEW OF THE LAST MONTH (November 2022)
Here is a link to a YouTube clip giving an animated loop of the isobars and
streamlines in the South pacific at youtu.be/qgPsVkd_U5U
Sea Surface temperature anomalies from psl.noaa.gov/map/clim/sst.shtml
The main pattern remains the same as since winter with the cool waters of La
Nina along the Eastern Equatorial Pacific surrounded by zones of warmer than
normal conditions in the north and south Pacific. The hot area that was off
Japan has relaxed. The rains over eastern Australian have run off and
produced a cool pool in the western Tasman sea .
Average isobars for past month
The Antarctic High has continued to weaken and thereby weakening the
southern polar vortex. The Artic low has almost disappeared. The southern
Subtropical ridge has noticeably weakened , except in the South Atlantic.
Pressure anomolies for past month
The lows that started over south Australia is early spring extended to NZ by
late spring. Rising pressures over the Aleutians and Canada and another zone
over northwest Europe is making the northern hemisphere a 2-wave pattern.
The Southern hemisphere is clearly in a 3-wave mode.
Zooming into the NZ area
On the tropical side the 1010 has drifted south onto northern Australia,
typical of summer. However, on the southern side the 1010 has shifted north
from Campbell Island to Taupo, due to the numerous lows and lack of highs
travelling across the Tasman Sea. This is more like a spring pattern.
TROPICS
There are no named storms at present. There is a zone of potential
development north of New Guinea.
WEATHER ZONES
The SPCZ is active at present in the eastern Coral Sea/Vanuatu/ New
Caledonia area but this should clear off to the southeast . Convergence zone
has cleared off French Polynesia at present. A Convergence zone now near
Samoa is expected to drift southeast to Southern cooks.
HIGHS and LOWS
HIGH H1 over North Island is expected to travel off to the east along 35S,
with a squash zone on its northern side around 27S.
Low L1 south of NZ is expected to travel east along 50S.
Low L2 is forming west of New Caledonia and expected to travel SE and fade
near Northland on Wed/Thurs, followed by H2.
Low L3 is expected to travel slowly Se from Bass strait into the south
Tasman Sea by mid-week and then Northeast towards central NZ by end of week.
HIGH H3 should banana around south side of L3 and build east of the South
Island by end of the week.
Looking Ok to sail to NZ next ten days, just divert around the lows.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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