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 17 August 2025
Are the Oceans now struggling to store extra earth heating?
See climatereanalyzer.org/clim/sst_daily/
Since July 2023 it is as if the global averaged sea temperature has
jumped into a new regime. We still cannot tell if this is a
fundamental change that may adversely energise further weather events.
In the first half of August the rise in daily global has been
extremely rapid.
Until now, 90 per cent of the excess heat created by greenhouse gas
emissions has been drawn down into the ocean. Under this new regime it
seems that this capacity for heat absorption is being lost. SO where
will the extra heat now get stored?
The Cape Reinga region over Far North New Zealand is having a winter
heatwave. However, Hauraki Gulf is just slightly above normal
See www.moanaproject.org/marine-heatwave-forecast
The rain accumulation for year to date shows that it has been wetter
than normal in northern NZ --- with the "wetter" kicking in around 21
April, and % excess much more in Auckland than around Kerikeri.
See Visual crossing data
TROPICS
. Southern Taiwan was lashed by Category-2 Typhoon Podul, which
weakened over the island before striking China's Fujian and Guangdong
provinces.
. Mexico's central Pacific coast was brushed by passing Tropical Storm
Ivo.
. Tropical Storm Awo formed briefly near Seychelles.
. Hurricane Erin is strengthening to Category-3 force north of Puerto
Rico.
WEATHER ZONES
Rain accumulation this week from Windy.com below shows well defined
SPCZ between Solomon Islands and Samo/Niue and a passing trough over
French Polynesia. Also, an area of rain along eastern seaboard of
Australia in onshore winds.
Wind accumulation from windy.com below shows a burst of strong
southerly winds over NZ in the wake of L1. Also, generally OK ailing
winds in the tropics.
LOWS and HIGHS
Low L1 is moving off to the east of New Zealand.
H1 starts off in Australian Bight and travel east along 45S across
South Tasman Sea mid-week and onto NZ next weekend.
L2 is expected to follow H1
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about your voyage, check metbob.com
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 text 64277762212.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
17 August 2025
10 August 2025
Bobgram 10 Aug
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 10 August 2025
TROPICS
The latest cyclone activity report is at zoom.earth and
tropic.ssec.wisc.edu and Tropical Cyclone Potential is from
http://www.ospo.noaa.gov/products/ocean/tropical/tcfp/
Tropical storm development across the Northern Hemisphere increased,
with Typhoon Krosa and Tropical Storm Bailu churning the western
Pacific.
. Hurricane Gil formed off Mexico, while Tropical Storm Henriette
passed northeast of Hawaii.
. Tropical Storm Dexter spun up over the Atlantic.
WEATHER ZONES
Weather Zones Mid-week GFS model showing isobars, winds, waves
(purple), rain (red), MT (Monsoonal trough), STR (Subtropical Ridge),
SPCZ (South Pacific Convergence Zone) CZ (Convergence Zone)
Rain accumulation this week from Windy.com shows well defined SPCZ
between Solomon Islands and Tuvalu. Also, heavy rain along 25S from
175E to Rarotonga (avoid).
Wind accumulation from windy.com shows zones of strong wind around L1.
There are also bursts of wind expected south of New Caledonia and off
Sydney later in the week. (avoid).
LOWS and HIGHS
Low L1 is deepening near New Caledonia tonight and expected to travel
slowly to East-southeast reaching 29S 175W by mid-week.
Another Low is expected to form between New Caledonia and Norfolk by
Friday and trave to Tonga 16/17 August (avoid).
HIGH H1 is expected to travel steadily east along 35 to 40S, starting
this week west of Perth, reaching Adelaide by Mid-week and crossing NZ
on Friday 15 Aug.
By then there may be a squash zone of strong easterly winds around 30S
between the High over NZ and the new Low then near Fiji. Avoid.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about your voyage, check metbob.com
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 text 64277762212.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Disclaimer: Weather is a mix of pattern and chaos; these ideas are
from the patterned world.
Compiled 10 August 2025
TROPICS
The latest cyclone activity report is at zoom.earth and
tropic.ssec.wisc.edu and Tropical Cyclone Potential is from
http://www.ospo.noaa.gov/products/ocean/tropical/tcfp/
Tropical storm development across the Northern Hemisphere increased,
with Typhoon Krosa and Tropical Storm Bailu churning the western
Pacific.
. Hurricane Gil formed off Mexico, while Tropical Storm Henriette
passed northeast of Hawaii.
. Tropical Storm Dexter spun up over the Atlantic.
WEATHER ZONES
Weather Zones Mid-week GFS model showing isobars, winds, waves
(purple), rain (red), MT (Monsoonal trough), STR (Subtropical Ridge),
SPCZ (South Pacific Convergence Zone) CZ (Convergence Zone)
Rain accumulation this week from Windy.com shows well defined SPCZ
between Solomon Islands and Tuvalu. Also, heavy rain along 25S from
175E to Rarotonga (avoid).
Wind accumulation from windy.com shows zones of strong wind around L1.
There are also bursts of wind expected south of New Caledonia and off
Sydney later in the week. (avoid).
LOWS and HIGHS
Low L1 is deepening near New Caledonia tonight and expected to travel
slowly to East-southeast reaching 29S 175W by mid-week.
Another Low is expected to form between New Caledonia and Norfolk by
Friday and trave to Tonga 16/17 August (avoid).
HIGH H1 is expected to travel steadily east along 35 to 40S, starting
this week west of Perth, reaching Adelaide by Mid-week and crossing NZ
on Friday 15 Aug.
By then there may be a squash zone of strong easterly winds around 30S
between the High over NZ and the new Low then near Fiji. Avoid.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about your voyage, check metbob.com
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 text 64277762212.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
03 August 2025
Bobgram 3 Aug 2025
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 3 August 2025
A review of last month's weather
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
youtu.be/gjWlhQmSeTs
Lows crossed NZ on 4-5, 11, 17 and 29-31 July …. Almost continuing a
weekly cycle, but also a blocking HIGH between 20 and 29 July.
The Low on 29-31 brought heavy rain to Tasman/Nelson/Marlborough area
and Bay of Plenty area.
The 500hPa heights and anomalies shows last month's typical ridge
/trough pattern,
From http://www.cpc.ncep.noaa.gov/products/intraseasonal/z500_sh_anim.
shtml
Sea Surface temperature anomalies
from psl.noaa.gov/map/clim/sst.shtml
The build-up of heat east of Japan an in the north Atlantic is
continuing.
The cooling /upwelling off Peru has finished.
The Sothern Annual Mode /AAO spent first half of July positive,
accentuating the polar vortex.
The monthly pressure pattern and anomalies are
from http://www.psl.noaa.gov/map/images/fnl/slp_30b.fnl.html
During July the roaring 40s in the southern hemisphere moved north.
The Subtropical ridge across the south Indian ocean intensified.
Pressure anomalies for past month Shows the pressure rise in south
Indian ocean to be part of a roller coast with lows over Australia and
larger Highs SE of NZ. Deeper lows over Asia.
The 1015 isobar has shifted north to cover the south half of Tasman
Sea.
A 1025 Isobar has formed in the Indian Ocean.
TROPICS
The latest cyclone activity report is at zoom.earth and
tropic.ssec.wisc.edu and Tropical Cyclone Potential is
from http://www.ospo.noaa.gov/products/ocean/tropical/tcfp/
After lashing the far northern Philippines as a Category-1 cyclone,
Tropical Storm Co-May drenched Okinawa before bringing heavy rain and
gales to the Chinese coast around Shanghai.
• Typhoon Krosa skirted the Japanese coast near Tokyo as a tropical
storm.
• Hurricane Iona and Tropical Storm Keli churned the open Pacific
Ocean, well to the south of Hawaii.
WEATHER ZONES
Weather Zones Mid-week GFS model showing isobars, winds, waves
(purple), rain (red), MT (Monsoonal trough), STR (Subtropical Ridge),
SPCZ (South Pacific Convergence Zone) CZ (Convergence Zone)
Rain accumulation this week from Windy.com shows well defined SPCZ
between Solomon Islands and Tuvalu. Also, a frontal zone from Tonga
to Austral Islands (avoid).
Wind accumulation from windy.com shows zones of strong wind around L1
and L2 and a frontal zone along 20S (avoid).
LOWS and HIGHS
Low L1 near 40S 160E, well south of Tahiti is moving off to the
southeast but leaving behind lots of southerly swell getting as far as
20S.
HIGH H1 has been travelling across New Zealand last few days and
should continue a steady eastward migration along 45S
Low 2 is the one that affected the third rugby test Wallabies beating
the British and Irish Lions in Stadium Australia, Sydney … a game
delayed by lightning and influenced by rain. This Low is being
steered east along 28S… an uncommon path for a low. So, there is a
squash zone between it and H1 with strong easterly winds and large
swells at 30S. Avoid.
Further west over Australia several troughs should travel southeast
across Tasmania and the South Tasman Sea reaching southern NZ by end
of the week and a large High H2 moves into the Aussie Bight and then
follows those troughs.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about your voyage, check metbob.com
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 text 64277762212.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Disclaimer: Weather is a mix of pattern and chaos; these ideas are
from the patterned world.
Compiled 3 August 2025
A review of last month's weather
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
youtu.be/gjWlhQmSeTs
Lows crossed NZ on 4-5, 11, 17 and 29-31 July …. Almost continuing a
weekly cycle, but also a blocking HIGH between 20 and 29 July.
The Low on 29-31 brought heavy rain to Tasman/Nelson/Marlborough area
and Bay of Plenty area.
The 500hPa heights and anomalies shows last month's typical ridge
/trough pattern,
From http://www.cpc.ncep.noaa.gov/products/intraseasonal/z500_sh_anim.
shtml
Sea Surface temperature anomalies
from psl.noaa.gov/map/clim/sst.shtml
The build-up of heat east of Japan an in the north Atlantic is
continuing.
The cooling /upwelling off Peru has finished.
The Sothern Annual Mode /AAO spent first half of July positive,
accentuating the polar vortex.
The monthly pressure pattern and anomalies are
from http://www.psl.noaa.gov/map/images/fnl/slp_30b.fnl.html
During July the roaring 40s in the southern hemisphere moved north.
The Subtropical ridge across the south Indian ocean intensified.
Pressure anomalies for past month Shows the pressure rise in south
Indian ocean to be part of a roller coast with lows over Australia and
larger Highs SE of NZ. Deeper lows over Asia.
The 1015 isobar has shifted north to cover the south half of Tasman
Sea.
A 1025 Isobar has formed in the Indian Ocean.
TROPICS
The latest cyclone activity report is at zoom.earth and
tropic.ssec.wisc.edu and Tropical Cyclone Potential is
from http://www.ospo.noaa.gov/products/ocean/tropical/tcfp/
After lashing the far northern Philippines as a Category-1 cyclone,
Tropical Storm Co-May drenched Okinawa before bringing heavy rain and
gales to the Chinese coast around Shanghai.
• Typhoon Krosa skirted the Japanese coast near Tokyo as a tropical
storm.
• Hurricane Iona and Tropical Storm Keli churned the open Pacific
Ocean, well to the south of Hawaii.
WEATHER ZONES
Weather Zones Mid-week GFS model showing isobars, winds, waves
(purple), rain (red), MT (Monsoonal trough), STR (Subtropical Ridge),
SPCZ (South Pacific Convergence Zone) CZ (Convergence Zone)
Rain accumulation this week from Windy.com shows well defined SPCZ
between Solomon Islands and Tuvalu. Also, a frontal zone from Tonga
to Austral Islands (avoid).
Wind accumulation from windy.com shows zones of strong wind around L1
and L2 and a frontal zone along 20S (avoid).
LOWS and HIGHS
Low L1 near 40S 160E, well south of Tahiti is moving off to the
southeast but leaving behind lots of southerly swell getting as far as
20S.
HIGH H1 has been travelling across New Zealand last few days and
should continue a steady eastward migration along 45S
Low 2 is the one that affected the third rugby test Wallabies beating
the British and Irish Lions in Stadium Australia, Sydney … a game
delayed by lightning and influenced by rain. This Low is being
steered east along 28S… an uncommon path for a low. So, there is a
squash zone between it and H1 with strong easterly winds and large
swells at 30S. Avoid.
Further west over Australia several troughs should travel southeast
across Tasmania and the South Tasman Sea reaching southern NZ by end
of the week and a large High H2 moves into the Aussie Bight and then
follows those troughs.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about your voyage, check metbob.com
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 text 64277762212.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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