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 June 23
WE'VE DONE IT – we have exceeded the 1.5C Threshold in June
As a sequel to last week's look at sea temperatures, I'm this week looking at surface air temperatures. The Climate watchers at climate.coernicus.eu have data that now shows that early this month temperatures exceeded the 1.5C Threshold.
In December 2015, the nations of the world adopted the Paris Agreement, under which they would pursue efforts to limit the rise in the climatological average global temperature to 1.5⁰C above pre-industrial levels.
Early this month for a few days the global-mean temperature was more than 1.5⁰C higher than the pre-industrial temperature for the month. (it has briefly been over the 1.5 C threshold before a few times… notably in 2015 around the time of the Paris Agreement signing, and also in early 2016 during the last El Nino. This is the first time it has happened in June, and that's one of the hottest months of the year.
As the current El Niño continues to develop there is good reason to expect periods in the coming twelve months during which the global-mean air temperature again exceeds pre-industrial levels by more than 1.5⁰C. What's more, according to a recent WMO report mentioned, there is a 98% likelihood that at least one of the next five years will be the warmest on record.
It must be stressed that the 1.5C and 2C limits set in the Paris Agreement are thirty-year period (climate epoch) targets for the average temperature of the planet. Passing the long-term global limits at any one time of year or any one place may not be of particular significance.
TROPICS
During the past week BRET and CINDY formed in the North Atlantic. There is a good potential that a cyclone will form this week off the Mexico west coast.
The MJO, a burst of extra energy in the tropics, is weak and in the Indian Ocean
WEATHER ZONES
The South Pacific Convergence zone SPCZ
is expected to retreat to the northern end of the Coral Sea.
A left-over convergence zone may linger about and to southeast of Southern Cooks
The subtropical ridge of light winds is expected to advance as far north as 17S between Fiji and Aitutaki,
so the westerly winds get as far north as Niue until end of local Monday
(wait until Tuesday for good conditions in the harbour).
HIGHS and LOWS
H1 well east of NZ should move away and H2 stay over mainland Australia this week.
The allows lows in between tom create lots of wind and swell.
L1 has been blocked to NE of North Island for days, flooding Gisborne area with tropical rains.
It is now expected to rotate clockwise and travel SW towards Chathams and then move off to the Sea.
By Thursday at 45S it may drop to 960 hPa, allowing an intense west/SW low across NZ and Tasman Sea with swells up to 9m in Tasman Sea and over 4m between NZ and the tropics. Avoid.
Low L2 starts near Cook strait and is expected to swirl NE around L1 then off to the east along 35S bringing a burst of extra squalls and swell. Avoid.
Low L3 is expected to move into the South Tasman Sea on Thursday and then towards Cook Strait/Chathams over the weekend. It MIGHT be followed by a High into the Tasman Sea early the following week.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about 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 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
25 June 2023
23 June 2023
18 June 2023
Bob Blog 18 June
Bob Blog 18 June
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 June 23
Dr Kevin Trenberth writes to theconservation.com : Highlights
El Niño is officially here, according to the US National Oceanic and
Atmospheric Administration, and with it comes a change from the La Niña
weather patterns New Zealand has experienced for the past three years.
Moreover, it was overdue. When La Niña finally gave up the ghost in March
this year, global sea surface temperatures were suddenly the highest on
record, as the tropical Pacific abruptly began to warm.
Meanwhile, record high sea surface temperatures in the extratropical North
and South Pacific were partly a signature from La Niña and partly a sign of
global warming. The resulting "atmospheric rivers" delivered torrential
rains to California in the north and New Zealand in the south.
These sea surface temperature changes can be readily seen by comparing
variations from mean temperatures for December 2022 versus May 2023 . May
2023 shows a startling transformation throughout the central tropical
Pacific, with a coastal El Niño off Peru and Ecuador strongly evident.
Modest cooling in the eastern North Pacific is associated with the train of
storms that barrelled into the West Coast of the US and in northwest
Australia from Cyclone Ilsa.
El Niño's impacts
The weather in the tropics is seldom average, however. It tends to fluctuate
more like a roller coaster. In the atmosphere, this is referred to as the
Southern Oscillation. The combined atmosphere and ocean phenomenon is often
referred to as the El Niño-Southern Oscillation (ENSO).
The bottom of the roller coaster is the cold phase: a basin-wide cooling of
the tropical Pacific, named La Niña, while the top of the roller coaster is
El Niño, which occurs every three to seven years or so.
El Niños tend to peak in December, although their biggest atmospheric
impacts may not be until February.
The warmest years in terms of global mean surface temperature are the latter
stages of El Niño events. 2016 is the world's warmest year on record, in
part because of the very strong El Niño event. But 2023 could beat that
record – and odds are that 2024 will beat it by a lot.
Globally, El Niño is the largest cause of droughts; they are more intense,
set in quicker and increase the risk of wildfires, especially in Australia,
Indonesia and Brazil. In the weak 2019-20 El Niño, smoke from fires in
eastern Australia affected the southern hemisphere to the extent that it
blocked the sun and may have exacerbated the subsequent La Niña conditions.
Meanwhile, torrential rains are heavier, with greater risk of flooding,
especially in Peru and Ecuador. Very wet conditions can also (though not
always) occur in California and the southeast US.
New Zealand tends to experience stronger and more frequent winds from the
southwest in winter and from the west in summer during El Niño. This can
encourage dryness in eastern areas and more rain on the West Coast, with
generally cooler conditions overall.
TROPICS
Cyclone BIPARJOY moved onto India during the past week.
There is an easterly wave in the mid-Atlantic and small depression off to
the west of Mexico
The MJO, a burst of extra energy in the tropics, is weak and in the Indian
Ocean
WEATHER ZONES
South Pacific Convergence Zone
SPCZ is expected to stretch from northern Coral Sea to Samoa to Southern
Cooks. A convergence zone near 12S is likely over northern Cooks. Southerly
swells up to 3m may affect as far north as Niue to Palmerston around
mid-week.
HIGHS and LOWS
High Hi is blocked and has a squash zone of strong easterly winds on its
northern side to NE of NZ. This is generating swells and some southerly 3m
swells may make it as far as Niue to Palmerston mid-week.
H1 is knocking Low L1 over northern NZ to the SW and L3 south of the Austral
Island to the SW.
Low L2 should travel from south of Tasmania into mid-Tasman by mid-week and
then across northern NZ. Avoid. After a brief ridge Low L4 is expected to
follow L3/
Keeping this cluster of lows in the Tasman Sea this week along with H1 is
High H2 stuck over Australia.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about 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 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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 June 23
Dr Kevin Trenberth writes to theconservation.com : Highlights
El Niño is officially here, according to the US National Oceanic and
Atmospheric Administration, and with it comes a change from the La Niña
weather patterns New Zealand has experienced for the past three years.
Moreover, it was overdue. When La Niña finally gave up the ghost in March
this year, global sea surface temperatures were suddenly the highest on
record, as the tropical Pacific abruptly began to warm.
Meanwhile, record high sea surface temperatures in the extratropical North
and South Pacific were partly a signature from La Niña and partly a sign of
global warming. The resulting "atmospheric rivers" delivered torrential
rains to California in the north and New Zealand in the south.
These sea surface temperature changes can be readily seen by comparing
variations from mean temperatures for December 2022 versus May 2023 . May
2023 shows a startling transformation throughout the central tropical
Pacific, with a coastal El Niño off Peru and Ecuador strongly evident.
Modest cooling in the eastern North Pacific is associated with the train of
storms that barrelled into the West Coast of the US and in northwest
Australia from Cyclone Ilsa.
El Niño's impacts
The weather in the tropics is seldom average, however. It tends to fluctuate
more like a roller coaster. In the atmosphere, this is referred to as the
Southern Oscillation. The combined atmosphere and ocean phenomenon is often
referred to as the El Niño-Southern Oscillation (ENSO).
The bottom of the roller coaster is the cold phase: a basin-wide cooling of
the tropical Pacific, named La Niña, while the top of the roller coaster is
El Niño, which occurs every three to seven years or so.
El Niños tend to peak in December, although their biggest atmospheric
impacts may not be until February.
The warmest years in terms of global mean surface temperature are the latter
stages of El Niño events. 2016 is the world's warmest year on record, in
part because of the very strong El Niño event. But 2023 could beat that
record – and odds are that 2024 will beat it by a lot.
Globally, El Niño is the largest cause of droughts; they are more intense,
set in quicker and increase the risk of wildfires, especially in Australia,
Indonesia and Brazil. In the weak 2019-20 El Niño, smoke from fires in
eastern Australia affected the southern hemisphere to the extent that it
blocked the sun and may have exacerbated the subsequent La Niña conditions.
Meanwhile, torrential rains are heavier, with greater risk of flooding,
especially in Peru and Ecuador. Very wet conditions can also (though not
always) occur in California and the southeast US.
New Zealand tends to experience stronger and more frequent winds from the
southwest in winter and from the west in summer during El Niño. This can
encourage dryness in eastern areas and more rain on the West Coast, with
generally cooler conditions overall.
TROPICS
Cyclone BIPARJOY moved onto India during the past week.
There is an easterly wave in the mid-Atlantic and small depression off to
the west of Mexico
The MJO, a burst of extra energy in the tropics, is weak and in the Indian
Ocean
WEATHER ZONES
South Pacific Convergence Zone
SPCZ is expected to stretch from northern Coral Sea to Samoa to Southern
Cooks. A convergence zone near 12S is likely over northern Cooks. Southerly
swells up to 3m may affect as far north as Niue to Palmerston around
mid-week.
HIGHS and LOWS
High Hi is blocked and has a squash zone of strong easterly winds on its
northern side to NE of NZ. This is generating swells and some southerly 3m
swells may make it as far as Niue to Palmerston mid-week.
H1 is knocking Low L1 over northern NZ to the SW and L3 south of the Austral
Island to the SW.
Low L2 should travel from south of Tasmania into mid-Tasman by mid-week and
then across northern NZ. Avoid. After a brief ridge Low L4 is expected to
follow L3/
Keeping this cluster of lows in the Tasman Sea this week along with H1 is
High H2 stuck over Australia.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about 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 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
11 June 2023
Bob Blog 11June
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 June 23
STANDING BY for EL NINO
The Bureau of Meteorology Australia have shifted their ENSO status to EL
NINO ALERT indicating that there is now a 70% chance of El Niño forming this
year. Central and eastern Pacific sea-surface temperatures (SSTs) have
warmed to El Niño thresholds. Some atmospheric indicators such as the
Southern Oscillation Index (SOI) have shifted towards El Niño thresholds,
but wind, cloud and broad-scale pressure patterns indicate that Ocean and
atmosphere are not yet in sync. It looks that this El Nino episode may start
by September and peak around the end of 2023.
May trade winds were close to normal in the central equatorial Pacific, but
a relaxation of trades in early and late June will enable further warming of
sea surface temperatures.
NIWA (NZ Climate institute) comment that the persistence of warmth in the
West Pacific is still encouraging low pressure systems to blossom in the
Tasman Sea area, and this may lengthen the transition window from La Niña
toward El Niño. Due to this lag they are forecasting an augmented La Nina
like rain pattern over the South Pacific with a DRY ZONE roughly near 15S
from Tuvalu to the Tuamotu Islands.
This pattern suggests the main rain from the SPCZ may stay well north of
normal, and the rain from passing troughs in the mid latites may mainly
affect 20 to 25S in the South Pacific.
From this forecast it appears that those sailing from Tahiti to Tonga in the
next months should, on average, look at a northern route via Suwarrow,
rather than a southern route via 20-25S
TROPICS
Cyclone GUCHOL is moving NE across the southern Japan offshore islands and
BIPARJOY os in the Arabian Sea.
The MJO, a burst of extra energy in the tropics, is now rebuilding in the
Indian Ocean, so that
WEATHER ZONES
South Pacific Convergence Zone
The South Pacific Convergence zone is expected to stretch from northern
Coral Sea to northern Tonga to Southern Cooks. A convergence zone near 12S
is likely from northern Cooks to midway between Marquesas and Tuamotu
Islands.
HIGHS and LOWS
Low L1 has been east of NZ all last week. It is now rotating clockwise to
the SW around a dance partner L2 east of Gisborne which is deepening
tonight. L2 should take the dance off to the east this week.
High H1 in the central Tasman Se is expected to cover NZ on Wednesday and
Thursday and then fade into a ridge east of the country.
Low L3 is expected to reach mid Tasman Sea by mid-week and then cross
northern NZ this weekend. Avoid.
The gulf of Panama = Not recommended due convergence zone and SW winds.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about 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 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the
patterned world.
Compiled Sunday 11 June 23
STANDING BY for EL NINO
The Bureau of Meteorology Australia have shifted their ENSO status to EL
NINO ALERT indicating that there is now a 70% chance of El Niño forming this
year. Central and eastern Pacific sea-surface temperatures (SSTs) have
warmed to El Niño thresholds. Some atmospheric indicators such as the
Southern Oscillation Index (SOI) have shifted towards El Niño thresholds,
but wind, cloud and broad-scale pressure patterns indicate that Ocean and
atmosphere are not yet in sync. It looks that this El Nino episode may start
by September and peak around the end of 2023.
May trade winds were close to normal in the central equatorial Pacific, but
a relaxation of trades in early and late June will enable further warming of
sea surface temperatures.
NIWA (NZ Climate institute) comment that the persistence of warmth in the
West Pacific is still encouraging low pressure systems to blossom in the
Tasman Sea area, and this may lengthen the transition window from La Niña
toward El Niño. Due to this lag they are forecasting an augmented La Nina
like rain pattern over the South Pacific with a DRY ZONE roughly near 15S
from Tuvalu to the Tuamotu Islands.
This pattern suggests the main rain from the SPCZ may stay well north of
normal, and the rain from passing troughs in the mid latites may mainly
affect 20 to 25S in the South Pacific.
From this forecast it appears that those sailing from Tahiti to Tonga in the
next months should, on average, look at a northern route via Suwarrow,
rather than a southern route via 20-25S
TROPICS
Cyclone GUCHOL is moving NE across the southern Japan offshore islands and
BIPARJOY os in the Arabian Sea.
The MJO, a burst of extra energy in the tropics, is now rebuilding in the
Indian Ocean, so that
WEATHER ZONES
South Pacific Convergence Zone
The South Pacific Convergence zone is expected to stretch from northern
Coral Sea to northern Tonga to Southern Cooks. A convergence zone near 12S
is likely from northern Cooks to midway between Marquesas and Tuamotu
Islands.
HIGHS and LOWS
Low L1 has been east of NZ all last week. It is now rotating clockwise to
the SW around a dance partner L2 east of Gisborne which is deepening
tonight. L2 should take the dance off to the east this week.
High H1 in the central Tasman Se is expected to cover NZ on Wednesday and
Thursday and then fade into a ridge east of the country.
Low L3 is expected to reach mid Tasman Sea by mid-week and then cross
northern NZ this weekend. Avoid.
The gulf of Panama = Not recommended due convergence zone and SW winds.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about 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 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
04 June 2023
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 June 23
A review of weather of the past month
Here is a link to a YouTube clip giving an animated loop of the isobars and
streamlines in the South Pacific for the last month
https://youtu.be/ttafdMxypnY
May 2023 brought an end to a blocking high east of New Zealand and then a
series of lows travelling east across the South Pacific. The Highs were
brief, making for very few good opportunities for sailing form NZ/Australia
to the tropics. The low on 20May was measured on my baro in Palmerston North
as 979h.
Warm sea temperatures continue to spread westwards along the equator from
Peru.
Marine heat wave around NZ has shifted towards Chathams. Another marine heat
wave covers eastern North Atlantic
Subtropical ridges have shifted northwards. Now the Arctic has high rather
than low pressures
The anomaly pattern in the southern hemisphere is almost the reverse of last
month's. In particular, both Arctic and Antarctic have flipped from positive
to negative .
The subtropical ridge has now drifted to a mean position north of NZ.
The 1015 isobar on its northern side now stretches from Australia north
coast to Tongatapu.
The westerly flow in the 40s and 50s is increasing.
TROPICS
Cyclone MAWAR dropped to an estimated central pressure of 897 hPa and Cat5
to Ne pf Philippines sand then faded on its way to southern Japan. There are
now tropical depressions I both west and east of the Philippines, where
potential is high for development this week.
The MJO, a burst of extra energy in the tropics, has finished crossing the
Pacific and a period of relative quiet is expected for next few weeks.
WEATHER ZONES
South Pacific Convergence Zone SPCZ
The South Pacific Convergence zone is expected to stretch from northern
Coral Sea to northern Fiji and northern Tonga areas. Another weaker
convergence zone is lingering between Northern Cooks and north of Tuamotu
Islands. A trough is expected over Fiji on Tuesday going southeast and
developing into a low south of Niue late in the week. Avoid.
HIGHS and LOWS
Low L1 is the surface reflection of a cold pool aloft and as such is
expected to travel only slowly across and to the east of northern NZ this
week. Avoid.
High H1 in the south Tasman Se is expected to swing around southern NZ and
to east of Chathams. This feeds cold sir into the moisture of L1 , a good
recipe for snow making in the squashed isobars between L1 and H1 over
central NZ. Avoid.
Low 2 well to south of Tahiti tonight is expected to deepen with the arrival
of a cold southerly and then travel off to the east.
The gulf of Panama = Not recommended due convergence zone and SW winds.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about 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 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the
patterned world.
Compiled Sunday 4 June 23
A review of weather of the past month
Here is a link to a YouTube clip giving an animated loop of the isobars and
streamlines in the South Pacific for the last month
https://youtu.be/ttafdMxypnY
May 2023 brought an end to a blocking high east of New Zealand and then a
series of lows travelling east across the South Pacific. The Highs were
brief, making for very few good opportunities for sailing form NZ/Australia
to the tropics. The low on 20May was measured on my baro in Palmerston North
as 979h.
Warm sea temperatures continue to spread westwards along the equator from
Peru.
Marine heat wave around NZ has shifted towards Chathams. Another marine heat
wave covers eastern North Atlantic
Subtropical ridges have shifted northwards. Now the Arctic has high rather
than low pressures
The anomaly pattern in the southern hemisphere is almost the reverse of last
month's. In particular, both Arctic and Antarctic have flipped from positive
to negative .
The subtropical ridge has now drifted to a mean position north of NZ.
The 1015 isobar on its northern side now stretches from Australia north
coast to Tongatapu.
The westerly flow in the 40s and 50s is increasing.
TROPICS
Cyclone MAWAR dropped to an estimated central pressure of 897 hPa and Cat5
to Ne pf Philippines sand then faded on its way to southern Japan. There are
now tropical depressions I both west and east of the Philippines, where
potential is high for development this week.
The MJO, a burst of extra energy in the tropics, has finished crossing the
Pacific and a period of relative quiet is expected for next few weeks.
WEATHER ZONES
South Pacific Convergence Zone SPCZ
The South Pacific Convergence zone is expected to stretch from northern
Coral Sea to northern Fiji and northern Tonga areas. Another weaker
convergence zone is lingering between Northern Cooks and north of Tuamotu
Islands. A trough is expected over Fiji on Tuesday going southeast and
developing into a low south of Niue late in the week. Avoid.
HIGHS and LOWS
Low L1 is the surface reflection of a cold pool aloft and as such is
expected to travel only slowly across and to the east of northern NZ this
week. Avoid.
High H1 in the south Tasman Se is expected to swing around southern NZ and
to east of Chathams. This feeds cold sir into the moisture of L1 , a good
recipe for snow making in the squashed isobars between L1 and H1 over
central NZ. Avoid.
Low 2 well to south of Tahiti tonight is expected to deepen with the arrival
of a cold southerly and then travel off to the east.
The gulf of Panama = Not recommended due convergence zone and SW winds.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about 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 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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