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 27 July 2025
The three limbs of climate change- extreme heat, extreme drought and
flash flooding have led to increasing food prices around the world.
The Barcelona Supercomputer centre BSC has produced the following map
of these food price spikes.
See
https://www.bsc.es/news/bsc-news/countries-across-the-world-see-food-p
rice-shocks-climate-extremes-research-involving-bsc-shows
TROPICS
TC WIPHA affected northern Philippine floods, killing at least three
people. Then it lashed Hong Kong and China's Guangdong province. It
then unleashed severe flooding across the northern half of Vietnam. .
Tropical storm Francisco formed near Japan's southernmost islands,
while Typhoon Co-May raked the northern Philippine, and TC KROSA
formed further east.
WEATHER ZONES
Rain accumulation above shows well defined SPCZ between Solomon
Islands and Tuvalu/Tokelau/Samoa with another arm of convergence from
Fiji to Tonga to Southern Cooks where it has peak intensity.
Also, dry zones in Coral Sea and over eastern South Island.
The wind accumulation shows gales with L3 near Lord Howe Island, a
possible mini-squash zone between Lau /Tonga /Niue and windy squalls
over Southern Cooks.
Also, a zone of light winds around Vanuatu and SE of South Island.
LOWS and HIGHS
HIGH H1 has brought a week of wintry frosty weather /light winds to NZ
and is now moving off to the east /southeast. It is pushing a large
Low L1 on its eastern side off to the southeast. There are some
min-squash zones on its northern side.
LOW2 has been blocked by HI1and its associated frontal zone has been
lingering in the Tasman Sea. L2 should travel of to the south and the
associated frontal zone is expected to cross Noumea on Monday, Fiji to
New Zealand on Tuesday and Wednesday, then Tonga on Thursday - maybe
with a small supporting Low. Then fade as it moves further east.
Avoid.
HIGH H2 is expected to travel east along 20S - this is almost as far
north as these Highs get. It should move across the Coral Sea /Noumea
area mid-week then fade.
LOW L3 has an interesting expected-track. Coming from a low that
deepens south of Albany on Monday, it is expected to get steered
across central Australia as a weakening feature on Tuesday and
Wednesday, then to deepen rapidly whilst crossing Tasman Sea on
Thursday and reach another peak in intensity below 990hPa when
crossing Northland on Friday. 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.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
27 July 2025
20 July 2025
Bobgram 20K=July 2025
Bob McDavitt's ideas for sailing around the South Pacific. 20 July
2025
Disclaimer: Weather is a mix of pattern and chaos; these ideas are
from the patterned world.
Calving Icebergs
Authorities in Innaarsuit, a tiny village in northwestern Greenland,
warned residents to be cautious as a pair of massive icebergs loomed
just offshore. There were fears that the massive chunks of ice could
create large waves that could sweep ashore. Government photos show
towering wedges of ice overshadowing homes and businesses in the
village, which has fewer than 200 people and relies heavily on
fishing.
https://www.bbc.com/news/world-europe-44831663
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 Nari skirted the coast of Japan's Honshu Island before
becoming the first such storm to make landfall on Hokkaido since 2016
EATHER 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
Rain accumulation above shows well defined SPCZ between Solomon
Islands and northern Vanuatu, and convergence zones between Samoa and
Southern cooks.
Also dry zones over NW Australia , in Coral sea and over NZ.
Wind and rain accumulation this week from Windy.com
The wind accumulation shows a squash zone along 30S between 180 and
160E.
Also, a zone of light winds over New Zealand. NO
LOWS and HIGHS
FINALLY, and for the first time this winter, we have a winter HIGH
over New Zealand this week. Light winds, often clear skies… good for
overnight frosts and valley fogs.
Low L1 near Norfolk on Monday is travelling east along 29S and taking
a trough/Convergence zone eastwards across Vanuatu on Monday then
Fiji/Tonga on local Wednesday then Niue on local Wednesday and
Southern cooks on local Thursday 35S and 145W (to southeast of French
Polynesia) is travelling southeast and associated trough is expected
to pass by Tahiti late this week, bringing small squalls and then a
lull.
HIGH H1 crossing New Zealand is expected to develop a squash zone of
strong easterly winds on its northern side along 30S between 180 and
160E for a time.
Trough T1 crossing the Tasman Sea following H1 this week may stall
near 160E and fade.
HIGH H2 is expected to cross central Australia this week and fade over
northern Tasman Sea this weekend as a developing Low from Australian
Bight moves into South Tasman Sea by early next week.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
2025
Disclaimer: Weather is a mix of pattern and chaos; these ideas are
from the patterned world.
Calving Icebergs
Authorities in Innaarsuit, a tiny village in northwestern Greenland,
warned residents to be cautious as a pair of massive icebergs loomed
just offshore. There were fears that the massive chunks of ice could
create large waves that could sweep ashore. Government photos show
towering wedges of ice overshadowing homes and businesses in the
village, which has fewer than 200 people and relies heavily on
fishing.
https://www.bbc.com/news/world-europe-44831663
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 Nari skirted the coast of Japan's Honshu Island before
becoming the first such storm to make landfall on Hokkaido since 2016
EATHER 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
Rain accumulation above shows well defined SPCZ between Solomon
Islands and northern Vanuatu, and convergence zones between Samoa and
Southern cooks.
Also dry zones over NW Australia , in Coral sea and over NZ.
Wind and rain accumulation this week from Windy.com
The wind accumulation shows a squash zone along 30S between 180 and
160E.
Also, a zone of light winds over New Zealand. NO
LOWS and HIGHS
FINALLY, and for the first time this winter, we have a winter HIGH
over New Zealand this week. Light winds, often clear skies… good for
overnight frosts and valley fogs.
Low L1 near Norfolk on Monday is travelling east along 29S and taking
a trough/Convergence zone eastwards across Vanuatu on Monday then
Fiji/Tonga on local Wednesday then Niue on local Wednesday and
Southern cooks on local Thursday 35S and 145W (to southeast of French
Polynesia) is travelling southeast and associated trough is expected
to pass by Tahiti late this week, bringing small squalls and then a
lull.
HIGH H1 crossing New Zealand is expected to develop a squash zone of
strong easterly winds on its northern side along 30S between 180 and
160E for a time.
Trough T1 crossing the Tasman Sea following H1 this week may stall
near 160E and fade.
HIGH H2 is expected to cross central Australia this week and fade over
northern Tasman Sea this weekend as a developing Low from Australian
Bight moves into South Tasman Sea by early next week.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
13 July 2025
Bobgram
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.
Today, 13 July is "Seafarers Sunday". On this day several churches pray special prayers for mariners and those who livelihood involves working on the ocean. This often-dangerous job, at mercy of winds and waves, requires spending weeks away from loved ones.
Over the centuries, seafarers have worked out rules to help avoiding sailing into the right parts of passing storms. Storms are often related to passing depressions or low-pressure systems as seen on a weather map. One of these rules is the "law of storms" as compiled in the mid-19th century (see metbob.wordpress.com/2025/06/16/bob-blog-15-june/)
Basically, this can be summarised that the way to go, to evade the roughest weather is to the right of the incoming wind.
Buys-Ballot law was compiled at much the same time. In the Southern hemisphere it can be stated thus: If you look into the wind then the LOW is on the left. This means concurs with the "law of storms" to go right or put wind on port in order to evade the worst of the storm.
However, when your voyage involves encountering a passing trough then the best thing to do is to put the incoming wind on starboard and sail directly into the approaching rain. By so doing we MINIMISE the time spent in the peak conditions of the trough. This is a case where the way to go is on a starboard tack, the opposite to the law of storms. My illustrated edition today at metbob.wordpress.com/2025/07/14/bob-blog-13-july/ gives more details of this exception.
TROPICS
* Typhoon Danas in Taiwan killed two people, and more than 300 were injured.
* Two deaths are being blamed on the flooding unleashed over the Carolinas by Tropical storm Chantal.
* TC NARI is affecting east coast of Japan.
WEATHER ZONES
Rain accumulation this week from Windy.com shows well defined SPCZ between Solomon Islands and Samoa. Also a passing trough southeast of French Polynesia .
The wind accumulation shows NO squash zones in the tropics, but the westerly winds of the "roaring 40s" are extending north of 30S around the south Pacific.
LOWS and HIGHS
Low L1 near 35S and 145W (to southeast of French Polynesia) is travelling southeast and associated trough is expected to pass by Tahiti late this week, bringing small squalls and then a lull.
HIGH H1 near 25S over Queensland is expected to stretch eastwards and keep a weak subtropical ridge between 25 and 30S across the South Pacific. taking a southern route from South of NZ along 45S.
Low tonight to NE of New Zealand is expected to travel south along 180. From mid-week on its front a secondary Low L2 is expected to form near35S and south of the Cooks Islands (near 160W).
Low L3 is expected to form over inland Australia on Tuesday then cross the Tasman on Wednesday and NZ on Thursday. Later in the week is may expand into a multi-system trough east of NZ.
L3 is followed by HIGH H travelling along 3o to 40S S and reaching NZ around Sun/Mon 19/20 July.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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.
Today, 13 July is "Seafarers Sunday". On this day several churches pray special prayers for mariners and those who livelihood involves working on the ocean. This often-dangerous job, at mercy of winds and waves, requires spending weeks away from loved ones.
Over the centuries, seafarers have worked out rules to help avoiding sailing into the right parts of passing storms. Storms are often related to passing depressions or low-pressure systems as seen on a weather map. One of these rules is the "law of storms" as compiled in the mid-19th century (see metbob.wordpress.com/2025/06/16/bob-blog-15-june/)
Basically, this can be summarised that the way to go, to evade the roughest weather is to the right of the incoming wind.
Buys-Ballot law was compiled at much the same time. In the Southern hemisphere it can be stated thus: If you look into the wind then the LOW is on the left. This means concurs with the "law of storms" to go right or put wind on port in order to evade the worst of the storm.
However, when your voyage involves encountering a passing trough then the best thing to do is to put the incoming wind on starboard and sail directly into the approaching rain. By so doing we MINIMISE the time spent in the peak conditions of the trough. This is a case where the way to go is on a starboard tack, the opposite to the law of storms. My illustrated edition today at metbob.wordpress.com/2025/07/14/bob-blog-13-july/ gives more details of this exception.
TROPICS
* Typhoon Danas in Taiwan killed two people, and more than 300 were injured.
* Two deaths are being blamed on the flooding unleashed over the Carolinas by Tropical storm Chantal.
* TC NARI is affecting east coast of Japan.
WEATHER ZONES
Rain accumulation this week from Windy.com shows well defined SPCZ between Solomon Islands and Samoa. Also a passing trough southeast of French Polynesia .
The wind accumulation shows NO squash zones in the tropics, but the westerly winds of the "roaring 40s" are extending north of 30S around the south Pacific.
LOWS and HIGHS
Low L1 near 35S and 145W (to southeast of French Polynesia) is travelling southeast and associated trough is expected to pass by Tahiti late this week, bringing small squalls and then a lull.
HIGH H1 near 25S over Queensland is expected to stretch eastwards and keep a weak subtropical ridge between 25 and 30S across the South Pacific. taking a southern route from South of NZ along 45S.
Low tonight to NE of New Zealand is expected to travel south along 180. From mid-week on its front a secondary Low L2 is expected to form near35S and south of the Cooks Islands (near 160W).
Low L3 is expected to form over inland Australia on Tuesday then cross the Tasman on Wednesday and NZ on Thursday. Later in the week is may expand into a multi-system trough east of NZ.
L3 is followed by HIGH H travelling along 3o to 40S S and reaching NZ around Sun/Mon 19/20 July.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
06 July 2025
Bobgram 6 June 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 6 July 2025
FNMOC is no more….
On June 25, 2025, the Trump administration issued a service change
notice announcing that the Defense Meteorological Satellite Program,
DMSP, and the Navy's Fleet Numerical Meteorology and Oceanography
Center would terminate data collection, processing and distribution of
all DMSP data no later than June 30. The data termination was
postponed until July 31 following a request from the head of NASA's
Earth Science Division.
The 2025 Atlantic hurricane season, which runs from June 1 to Nov. 30,
is forecast to be above average, with six to 10 hurricanes. The most
active part of the season runs from the middle of August to the middle
of October, after the DMSP satellite data is set to be turned off.
Hurricane forecasters will continue to use all available tools,
including satellite, radar, weather balloon and dropsonde data, to
monitor the tropics and issue hurricane forecasts. But the loss of
satellite data, along with other cuts to data, funding and staffing,
will make the forecasting harder.
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/y5BpNdbsX0E
Lows crossed NZ on 4-5, 12-13,20-21 and 27-28 June…. A weekly cycle
The Low on 27-28 brough heavy flowing to Tasman/Nelson/Marlborough
area and wind and rain damage to Taranaki.
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 as at 30 May
from psl.noaa.gov/map/clim/sst.shtml
The build up of heat east of Japan an in the north Atlantic is
concerning.
The cooling /upwelling off Peru is interesting.
The monthly pressure pattern and anomalies are
from http://www.psl.noaa.gov/map/images/fnl/slp_30b.fnl.html
During June the sub-tropical ridge in southern hemisphere has widened
and shifted north. The heat low over Asia has intensified and
pressures have fallen over Siberia.
Pressure anomalies for past month Shows lows forming around south
Australia. Also, higher than normal pressures around Indonesia.
The 1020 isobar has disappeared off NZ and shifted north (and shrunk)
over Australia.
The isobars are closer together over the Southern Ocean in June than
they were in May .
TROPICS
The latest cyclone activity report
Barry was a tropical storm for only about 12 hours after it formed in
Mexico's Bay of Campeche. It brought moderate rain to northeastern
Mexico.
• Hurricane Flossie intensified rapidly off Mexico's Pacific coast as
Typhoon Mun and Dunas formed near Japan.
WEATHER ZONES
Rain accumulation this week from Windy.com shows well defined SPCZ
between Solomon Islands and Samoa. Also a passing trough south of
French Polynesia .
The wind accumulation shows NO squash zones in the tropics, but there
is a windy passing trough east of New Caledonia and south of Fiji.
Also, a windy zone associated with the passing trough south of Tahiti.
LOWS and HIGHS
HIGH H1 is taking a southern route from South of NZ along 45S.
Low L1 is an amalgam of several smaller lows all under one large upper
trough. Some of these are the remains of the East coast low that
thrashed Sydney last Thursday. It gets onto the western side of the
upper trough and thus is steered NE towards 25S before then turning
south again mid-week. This is likely to bring a few days of northerly
then westerly winds to islands in Southern Cooks… not nice.
Not shown on that Wednesday map is a weak east coast low forming off
Sydney tonight then fading in Tasman Sea on Tuesday but associated
front and westerly winds bring strong winds to Tasman Sea south of
30S.
L1 is followed by H2 from central Australia but H2 fades away in north
Tasman Sea.
The reverse is expected further south, with L2 from the Australian
bight moving south of Tasmania by mid-week and forming a secondary L3
on its NW shoulder/ L3 then deepens in 3 days and travels across NZ
next Friday and weekend, keeping with the weekly pattern.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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 6 July 2025
FNMOC is no more….
On June 25, 2025, the Trump administration issued a service change
notice announcing that the Defense Meteorological Satellite Program,
DMSP, and the Navy's Fleet Numerical Meteorology and Oceanography
Center would terminate data collection, processing and distribution of
all DMSP data no later than June 30. The data termination was
postponed until July 31 following a request from the head of NASA's
Earth Science Division.
The 2025 Atlantic hurricane season, which runs from June 1 to Nov. 30,
is forecast to be above average, with six to 10 hurricanes. The most
active part of the season runs from the middle of August to the middle
of October, after the DMSP satellite data is set to be turned off.
Hurricane forecasters will continue to use all available tools,
including satellite, radar, weather balloon and dropsonde data, to
monitor the tropics and issue hurricane forecasts. But the loss of
satellite data, along with other cuts to data, funding and staffing,
will make the forecasting harder.
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/y5BpNdbsX0E
Lows crossed NZ on 4-5, 12-13,20-21 and 27-28 June…. A weekly cycle
The Low on 27-28 brough heavy flowing to Tasman/Nelson/Marlborough
area and wind and rain damage to Taranaki.
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 as at 30 May
from psl.noaa.gov/map/clim/sst.shtml
The build up of heat east of Japan an in the north Atlantic is
concerning.
The cooling /upwelling off Peru is interesting.
The monthly pressure pattern and anomalies are
from http://www.psl.noaa.gov/map/images/fnl/slp_30b.fnl.html
During June the sub-tropical ridge in southern hemisphere has widened
and shifted north. The heat low over Asia has intensified and
pressures have fallen over Siberia.
Pressure anomalies for past month Shows lows forming around south
Australia. Also, higher than normal pressures around Indonesia.
The 1020 isobar has disappeared off NZ and shifted north (and shrunk)
over Australia.
The isobars are closer together over the Southern Ocean in June than
they were in May .
TROPICS
The latest cyclone activity report
Barry was a tropical storm for only about 12 hours after it formed in
Mexico's Bay of Campeche. It brought moderate rain to northeastern
Mexico.
• Hurricane Flossie intensified rapidly off Mexico's Pacific coast as
Typhoon Mun and Dunas formed near Japan.
WEATHER ZONES
Rain accumulation this week from Windy.com shows well defined SPCZ
between Solomon Islands and Samoa. Also a passing trough south of
French Polynesia .
The wind accumulation shows NO squash zones in the tropics, but there
is a windy passing trough east of New Caledonia and south of Fiji.
Also, a windy zone associated with the passing trough south of Tahiti.
LOWS and HIGHS
HIGH H1 is taking a southern route from South of NZ along 45S.
Low L1 is an amalgam of several smaller lows all under one large upper
trough. Some of these are the remains of the East coast low that
thrashed Sydney last Thursday. It gets onto the western side of the
upper trough and thus is steered NE towards 25S before then turning
south again mid-week. This is likely to bring a few days of northerly
then westerly winds to islands in Southern Cooks… not nice.
Not shown on that Wednesday map is a weak east coast low forming off
Sydney tonight then fading in Tasman Sea on Tuesday but associated
front and westerly winds bring strong winds to Tasman Sea south of
30S.
L1 is followed by H2 from central Australia but H2 fades away in north
Tasman Sea.
The reverse is expected further south, with L2 from the Australian
bight moving south of Tasmania by mid-week and forming a secondary L3
on its NW shoulder/ L3 then deepens in 3 days and travels across NZ
next Friday and weekend, keeping with the weekly pattern.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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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