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 30 March 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 at
youtu.be/BeSWQwlK3qg
At the start of MARCH an MJO was affecting the South Pacific and
Cyclone ALFRED brought damaging wind and rain to the Brisbane area.
By mid-month the MJO moved on, but for the rest of the month a
monsoonal trough affected inland Australia and large anticyclones
travelled across central NZ.
March 2025 with its well-defined highs in the Tasman was a very good
weather pattern for Kiwi Grant "Axe' Rawlinson and Tasmania Luke
Richmond to row from Northland, NZ to Coffs harbour, arriving at beer
o'clock last Friday.
www.nbnnews.com.au/2025/03/29/record-breaking-row-across-tasman-sea/
axeoneverest.com/2025/03/28/tasman-2025-success-arrived-survived/
The trip took 22 days 4 hours and 40 minutes, and that's about 9days
faster than the 2007 trans-Tasman row.
The 500hPa heights and anomalies shows last month's typical ridge
/trough pattern, with the Highs showing either wave 2 or wave 4 ,
briefly wave 3, see
http://www.cpc.ncep.noaa.gov/products/intraseasonal/z500_sh_anim.shtm
l
Sea Surface temperature anomalies from psl.noaa.gov/map/clim/sst.shtml
show that the Galapagos area is now showing some warm anomalies.
There is a cold anomaly along the Canadian east coast. Around
80percent of the globe is showing warm anomalies.
At http://www.psl.noaa.gov/map/images/fnl/slp_30b.fnl.html
The Aleutian low and Greenland lows have relaxed since last month.
The subtropical ridges in both the Northern and Southern hemisphere is
well defined.
Pressure anomalies for past month (below)
The anomaly pressure pattern shows the monsoonal trough over
Australia.
The 1020 isobar covers the Tasman Sea.
The 1015 line has moved north across southern Australia
The 1010 isobar has retreated from Fiji westwards to Queensland.
TROPICS
Cyclone COURTNEY is over the open Indian Ocean.
WEATHER ZONES
Rain accumulation this week from Windy.com shows heaviest rain with L2
on South Island north and west coasts. Avoid.
The wind accumulation shows where to avoid the trails of wind mapped
out by L1 and L2
LOWS and HIGHS
Low L1 now south of Southern Cooks is moving slowly SE. Associated
trough is expected travel from Niue to Southern Cross this week, and
the southerly swells on its backside are expected to reach French
Polynesia late in the week.
HIGH H1 should travel east from South Tasman Sea to eats of the North
Island blocking L2
Low L2 is an east coast low that formed off Sydney today. It is
trapped in the Tasman Sea and is expected to finally cross Southland
area late this week. Avoid.
HIGH H2 is expected to maintain a ridge in the Australian Bight.
Low L3 is contained within the Monsoonal trough over inland Australia.
It is expected to become an East coast low off Brisbane o Wednesday
and then cross North Island late Friday followed by a westerly flow.
Gulf of Panama: Some light winds next few days then useful NE winds
after Tuesday. Showery.
5N to Galapagos: Light winds often from behind. Good tail currents
towards 2N, but a head current to the east about the Galapagos.
Showery south of 2N
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
30 March 2025
23 March 2025
Bobgram 23 March
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 23 March 2025
WMD
Today is the 75th World Meteorological day
On 23 March each year all meteorologists around the world commemorate
the commencement of WMO on this date in 1950.
The weather does NOT acknowledge any national boundaries and to gather
a working knowledge of what's happening we need observations from all
nations. Hence the WMO is needed to settle standards of observation
and share all weather data for our mutual benefit.
It has become a day whereby WMO can educate us all about important
matters. This year's theme is "Closing the early warning gap
together".
Over the past decade Governments around the word have been working on
how to get severe weather warnings enacted as quick and effectively as
possible. Even though the number intensity and cost of severe weather
events has been trending UP, the number of fatalities has been much
the same or even falling
WMO is now at the halfway mark of their Early Warnings for All
initiative, and significant progress has been made in saving lives,
protecting livelihoods, and strengthening community resilience. As
climate risks escalate, the urgency of the initiative continues to
grow.
These numbers show where we are
55%
As of 2024, 108 countries report having some capacity for multi-hazard
early warning systems, more than double the 52 countries in 2015.
Vulnerable Nations Progress
The least developed countries have shown the most significant
improvements, with landlocked developing countries and small island
developing states also surpassing the global rate.
+39%
The global average score for the comprehensiveness of multi-hazard
early warning systems has risen from 0.35 to 0.49, an increase of 39%.
Here is a link to a You Tube video on Severe Weather Warnings
https://youtu.be/35FvB7lst6o
"EVERY DOLLAR SPENT ON EARLY WARNING SAVES ON AVERAGE TEN DOLLARS IN
AVOIDABLE LOSSES."
TROPICS
. Tropical Storm Jude: After leaving at least nine people dead in
Mozambique and Malawi during the previous week, it drifted back over
the Mozambique Channel, where near-record high sea surface
temperatures fueled its regrowth. Jude then drenched southern
Madagascar, becoming the third tropical cyclone to rake the same
region so far this year.
. An unnamed tropical storm spun up near Australia's remote Cocos
Islands Indian Ocean territory.
WEATHER ZONES
Rain accumulation this week from Windy.com shows an intense SPCZ and
the heavy rain especially from NW Australia to Queensland. Yes, we
have the extra oomph of a MJO over northern Australia this week and
YES, it is expected to cross the Pacific over the following two weeks.
Wind accumulation this week from Windy.com
The wind accumulation shows a white trail with the Low in the Indian
Ocean. There is also extra wind and swell associated with the low near
the Kermadecs.
LOWS and HIGHS
Low L1 is expected to form just east of the Kermadecs by Tuesday and
then travel southeast this week
Hights H1, H2 and H3 are located between 40 and 45S and by mid-week
should be near 145W, 160E and 120E -consistent with a steady "wave 4"
around the planet.
The trough between Highs 2 and 3 is expected to cross NZ on Thursday
with some brief rain and a one-day southerly.
The SAM index/AAO index is positive and its trend this week is to
remain positive, so the fronts and SW wind bursts are not expected to
get far north this week.
High H1 in Tasman Sea is expected this week to travel across NZ on
Wednesday and Thursday. Before this there is a weak cold front/SW
change on Monday and Tuesday, but this is expected to weaken.
Panama Gulf to Galapagos: Good NE winds for starters and to 5N then OK
easterly or light winds and a good tail current to Galapagos.
Scattered tropical showers.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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 23 March 2025
WMD
Today is the 75th World Meteorological day
On 23 March each year all meteorologists around the world commemorate
the commencement of WMO on this date in 1950.
The weather does NOT acknowledge any national boundaries and to gather
a working knowledge of what's happening we need observations from all
nations. Hence the WMO is needed to settle standards of observation
and share all weather data for our mutual benefit.
It has become a day whereby WMO can educate us all about important
matters. This year's theme is "Closing the early warning gap
together".
Over the past decade Governments around the word have been working on
how to get severe weather warnings enacted as quick and effectively as
possible. Even though the number intensity and cost of severe weather
events has been trending UP, the number of fatalities has been much
the same or even falling
WMO is now at the halfway mark of their Early Warnings for All
initiative, and significant progress has been made in saving lives,
protecting livelihoods, and strengthening community resilience. As
climate risks escalate, the urgency of the initiative continues to
grow.
These numbers show where we are
55%
As of 2024, 108 countries report having some capacity for multi-hazard
early warning systems, more than double the 52 countries in 2015.
Vulnerable Nations Progress
The least developed countries have shown the most significant
improvements, with landlocked developing countries and small island
developing states also surpassing the global rate.
+39%
The global average score for the comprehensiveness of multi-hazard
early warning systems has risen from 0.35 to 0.49, an increase of 39%.
Here is a link to a You Tube video on Severe Weather Warnings
https://youtu.be/35FvB7lst6o
"EVERY DOLLAR SPENT ON EARLY WARNING SAVES ON AVERAGE TEN DOLLARS IN
AVOIDABLE LOSSES."
TROPICS
. Tropical Storm Jude: After leaving at least nine people dead in
Mozambique and Malawi during the previous week, it drifted back over
the Mozambique Channel, where near-record high sea surface
temperatures fueled its regrowth. Jude then drenched southern
Madagascar, becoming the third tropical cyclone to rake the same
region so far this year.
. An unnamed tropical storm spun up near Australia's remote Cocos
Islands Indian Ocean territory.
WEATHER ZONES
Rain accumulation this week from Windy.com shows an intense SPCZ and
the heavy rain especially from NW Australia to Queensland. Yes, we
have the extra oomph of a MJO over northern Australia this week and
YES, it is expected to cross the Pacific over the following two weeks.
Wind accumulation this week from Windy.com
The wind accumulation shows a white trail with the Low in the Indian
Ocean. There is also extra wind and swell associated with the low near
the Kermadecs.
LOWS and HIGHS
Low L1 is expected to form just east of the Kermadecs by Tuesday and
then travel southeast this week
Hights H1, H2 and H3 are located between 40 and 45S and by mid-week
should be near 145W, 160E and 120E -consistent with a steady "wave 4"
around the planet.
The trough between Highs 2 and 3 is expected to cross NZ on Thursday
with some brief rain and a one-day southerly.
The SAM index/AAO index is positive and its trend this week is to
remain positive, so the fronts and SW wind bursts are not expected to
get far north this week.
High H1 in Tasman Sea is expected this week to travel across NZ on
Wednesday and Thursday. Before this there is a weak cold front/SW
change on Monday and Tuesday, but this is expected to weaken.
Panama Gulf to Galapagos: Good NE winds for starters and to 5N then OK
easterly or light winds and a good tail current to Galapagos.
Scattered tropical showers.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
16 March 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.
Compiled 16 March 2025
How goes our Modoki La Nina
Looking at the ocean...
Modoki is a Japanese word loosely translated to "similar, but
different" or in New Zealand slang "Yeah, nah". Professor Toshio
Yamagata and a colleague named the phenomenon while investigating the
causes of Japan's hot summer in 2004.
This occurs when the Sea surface temperature SST in the central
equatorial Pacific cools, while the SST in the western and eastern
parts warm.
This differs from the regular La Nina where the cool zone is in the
eastern equatorial Pacific near the Galapagos.
A recent time section of SST anomalies near the equator and across the
Pacific, shows the cool zone of this La Nina is edging towards the 180
longitude. See psl.noaa.gov/map/clim/sst.shtml
The ENSO trend is followed by forecasting the SST for region NINO 3.4,
with values less than 0.5 needed for a La Nina event..
The combo of forecasts as calculated by IRI shows that
The Dynamic average forecast (red) stays below the La Nina threshold
(neutral)
and the Static model average (green) stays just over the La Nina
threshold until December this year.
I suppose we are somewhere in between.
Looking at the atmosphere...
The SOI index over the past month has been positive but trending to
zero.
TROPICS
There are no named cyclones around at present
In the past week Category-1
. Cyclone Jude killed at least six people when it roared onto
Mozambique's northeastern coast with winds of up to 75 mph, causing
significant flooding and extensive damage.
. Cyclone Ivone churned the open waters of the central Indian Ocean.
At present the MJO is poised to bring a new boost of energy onto
northern Australia over next few weeks and then into the Pacific by
early April
As seen at
www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/forca.shtml
WEATHER ZONES
The wind accumulation shows that the windy signature around the lows
and convergence zones.
The South Pacific Convergence zone SPCZ and tropical convergence is
very active over northern Australia. There was an active convergence
zone over Fiji /Samoa last week and it has travelled south and can be
seen going SE in the wind and rain accumulation forecasts.
This week is looking relatively quiet in the South Pacific tropics.
LOWS and HIGHS
An active Low and Front labelled L1 south of Tahiti is expected to go
off to the SSE.
The HIGH H1 now east of the North Island and with a ridge over
northern NZ, is expected to move off to the SE.
The Low labelled L2 east of Tasmania and its associated front is
expected to travel over NZ on Monday/Tuesday followed by a southerly
flow on Wednesday.
HIGH H2 now in Australian Bight is expected to follow L2 and cross NZ
on Thursday and Friday.
L3 is expected to travel east so that associated front reaches NZ on
Sat/Sunday.
In Gulf of Panama: Useful NE winds for starters but they may be over
20kt between Tuesday and Saturday.
From Panama to Galapagos.. SW swells 1 to 2m. Tail currents and mostly
a tail wind.
May be showery between 4 and 1N
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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 16 March 2025
How goes our Modoki La Nina
Looking at the ocean...
Modoki is a Japanese word loosely translated to "similar, but
different" or in New Zealand slang "Yeah, nah". Professor Toshio
Yamagata and a colleague named the phenomenon while investigating the
causes of Japan's hot summer in 2004.
This occurs when the Sea surface temperature SST in the central
equatorial Pacific cools, while the SST in the western and eastern
parts warm.
This differs from the regular La Nina where the cool zone is in the
eastern equatorial Pacific near the Galapagos.
A recent time section of SST anomalies near the equator and across the
Pacific, shows the cool zone of this La Nina is edging towards the 180
longitude. See psl.noaa.gov/map/clim/sst.shtml
The ENSO trend is followed by forecasting the SST for region NINO 3.4,
with values less than 0.5 needed for a La Nina event..
The combo of forecasts as calculated by IRI shows that
The Dynamic average forecast (red) stays below the La Nina threshold
(neutral)
and the Static model average (green) stays just over the La Nina
threshold until December this year.
I suppose we are somewhere in between.
Looking at the atmosphere...
The SOI index over the past month has been positive but trending to
zero.
TROPICS
There are no named cyclones around at present
In the past week Category-1
. Cyclone Jude killed at least six people when it roared onto
Mozambique's northeastern coast with winds of up to 75 mph, causing
significant flooding and extensive damage.
. Cyclone Ivone churned the open waters of the central Indian Ocean.
At present the MJO is poised to bring a new boost of energy onto
northern Australia over next few weeks and then into the Pacific by
early April
As seen at
www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/forca.shtml
WEATHER ZONES
The wind accumulation shows that the windy signature around the lows
and convergence zones.
The South Pacific Convergence zone SPCZ and tropical convergence is
very active over northern Australia. There was an active convergence
zone over Fiji /Samoa last week and it has travelled south and can be
seen going SE in the wind and rain accumulation forecasts.
This week is looking relatively quiet in the South Pacific tropics.
LOWS and HIGHS
An active Low and Front labelled L1 south of Tahiti is expected to go
off to the SSE.
The HIGH H1 now east of the North Island and with a ridge over
northern NZ, is expected to move off to the SE.
The Low labelled L2 east of Tasmania and its associated front is
expected to travel over NZ on Monday/Tuesday followed by a southerly
flow on Wednesday.
HIGH H2 now in Australian Bight is expected to follow L2 and cross NZ
on Thursday and Friday.
L3 is expected to travel east so that associated front reaches NZ on
Sat/Sunday.
In Gulf of Panama: Useful NE winds for starters but they may be over
20kt between Tuesday and Saturday.
From Panama to Galapagos.. SW swells 1 to 2m. Tail currents and mostly
a tail wind.
May be showery between 4 and 1N
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
09 March 2025
Bobgram 9 March
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 9 March 2025
The March of the Sun in March
During March the latitude of the overhead sun (also known as the sun's
declination) changes from 10S to 5N. On the 21st it is over the
equator, and we call that event the equinox (10:01pm, Tuesday 20 March
NZDT).
When the overhead sun is between 10 and 5S in early March it often is
associated with the formation of a convergence zone located SW of
Galapagos. This convergence zone mimics the intensity and mirrors the
position of the Intertropical convergence zone:
This year it has produced a strong east going surface current around
the Galapagos:
This poses challenges to anyone attempting the Panama to Galapagos
voyage over the next few weeks
TROPICS
The latest cyclone activity report is at zoom.earth and
tropic.ssec.wisc.edu and Tropical Cyclone Potential is from
www.ospo.noaa.gov/products/ocean/tropical/
GARANCE got to Cat 3 near the island of Réunion killing at least 5
people.
HONDE left at least three people dead and numerous buildings wrecked
in southern Madagascar. •
ALFRED brought a storm surge and heavy rain to Brisbane, killing at
least one person.
We can see how the track of cyclone stutters by watching ALFRED
approach Brisbane…
Last Tuesday/Wednesday what date/place would you have picked for
landfall, and how wrong would you have been?
JUDE is skirting around Madagascar
IVONE is over open sea in mid-south Indian Ocean.
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 The SPCZ active over
Vanuatu and Fiji. Alos there is another active convergence zone over
Samoa with flood warning.
And there is that "mirror convergence zone" at 5S to SW of Galapagos.
heavy rain from Tonga to Niue and with ALFRED.
Wind accumulation this week from Windy.com
The wind/rain accumulation shows trails of wind and rain mapped out by
L1
LOWS and HIGHS
Low L1 is expected to form (from under an upper cut off) to the NE of
northland on Monday and then travel to SE
A cold front /trough is expected to cross NZ on Monday/Tuesday
followed by a southerly flow. In this cold air a Low is expected to
form neat Chatham Island by late Thursday and then move off to the
east.
HIGH H1 south of Tasmania on Monday is expected to be diverted so that
is travels slowly north across the Tasman Sea this week. It should
push a ridge over southern and central NZ on Thursday and then weaken
into a ridge over Northland by end o week.
ALFRED is moving slowly south and MIGHT go inland late in the week
near Brisbane.
HIGH H1 now over North Island is moving off to the ESE.
This allows an active cold front to travel NE over NZ on Monday and
Tuesday and then form a Low L2 near Chathams on Wednesday with a
strong SE flow over NZ.
That should be followed by H2 now in Australian Bight and travelling
east across South Tasman mid-week then onto Northland for the weekend.
Low L2 in Australian Bight is expected to travel SE. Associated FRONT
is expected to travel east and cross NZ on Friday and Saturday
followed by a westerly with some strong winds.
HIGH H2 in Aussies bight is expected to be diverted to north of Hobart
and then northward to merge with H1.
Gulf of Panama: A useful NE flow for starters
Galapagos: There is a "mirror" CONVERGENCE ZONE with squalls a about
and mainly to SW of the group. Strong East to SE flowing surface
current around the group this 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.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Disclaimer: Weather is a mix of pattern and chaos; these ideas are
from the patterned world.
Compiled 9 March 2025
The March of the Sun in March
During March the latitude of the overhead sun (also known as the sun's
declination) changes from 10S to 5N. On the 21st it is over the
equator, and we call that event the equinox (10:01pm, Tuesday 20 March
NZDT).
When the overhead sun is between 10 and 5S in early March it often is
associated with the formation of a convergence zone located SW of
Galapagos. This convergence zone mimics the intensity and mirrors the
position of the Intertropical convergence zone:
This year it has produced a strong east going surface current around
the Galapagos:
This poses challenges to anyone attempting the Panama to Galapagos
voyage over the next few weeks
TROPICS
The latest cyclone activity report is at zoom.earth and
tropic.ssec.wisc.edu and Tropical Cyclone Potential is from
www.ospo.noaa.gov/products/ocean/tropical/
GARANCE got to Cat 3 near the island of Réunion killing at least 5
people.
HONDE left at least three people dead and numerous buildings wrecked
in southern Madagascar. •
ALFRED brought a storm surge and heavy rain to Brisbane, killing at
least one person.
We can see how the track of cyclone stutters by watching ALFRED
approach Brisbane…
Last Tuesday/Wednesday what date/place would you have picked for
landfall, and how wrong would you have been?
JUDE is skirting around Madagascar
IVONE is over open sea in mid-south Indian Ocean.
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 The SPCZ active over
Vanuatu and Fiji. Alos there is another active convergence zone over
Samoa with flood warning.
And there is that "mirror convergence zone" at 5S to SW of Galapagos.
heavy rain from Tonga to Niue and with ALFRED.
Wind accumulation this week from Windy.com
The wind/rain accumulation shows trails of wind and rain mapped out by
L1
LOWS and HIGHS
Low L1 is expected to form (from under an upper cut off) to the NE of
northland on Monday and then travel to SE
A cold front /trough is expected to cross NZ on Monday/Tuesday
followed by a southerly flow. In this cold air a Low is expected to
form neat Chatham Island by late Thursday and then move off to the
east.
HIGH H1 south of Tasmania on Monday is expected to be diverted so that
is travels slowly north across the Tasman Sea this week. It should
push a ridge over southern and central NZ on Thursday and then weaken
into a ridge over Northland by end o week.
ALFRED is moving slowly south and MIGHT go inland late in the week
near Brisbane.
HIGH H1 now over North Island is moving off to the ESE.
This allows an active cold front to travel NE over NZ on Monday and
Tuesday and then form a Low L2 near Chathams on Wednesday with a
strong SE flow over NZ.
That should be followed by H2 now in Australian Bight and travelling
east across South Tasman mid-week then onto Northland for the weekend.
Low L2 in Australian Bight is expected to travel SE. Associated FRONT
is expected to travel east and cross NZ on Friday and Saturday
followed by a westerly with some strong winds.
HIGH H2 in Aussies bight is expected to be diverted to north of Hobart
and then northward to merge with H1.
Gulf of Panama: A useful NE flow for starters
Galapagos: There is a "mirror" CONVERGENCE ZONE with squalls a about
and mainly to SW of the group. Strong East to SE flowing surface
current around the group this 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.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
02 March 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.
Compiled 2 March 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 at
youtu.be/R1DQQPwkNYE
During February the climate modellers agreed the Pacific is in ENSO
neutral territory. The MJO travelled across the South Pacific during
the month activating the South Pacific Convergence zone and forming a
series of 7 tropical lows with 3 of them becoming cyclones in the last
week.
The 500hPa heights and anomalies shows last month's typical ridge
/trough pattern, after a troughy January.
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 fading blue tongue along the central Pacific shows we are in ENSO
neutral territory.
Average isobars for past month (below)
From http://www.psl.noaa.gov/map/images/fnl/slp_30b.fnl.html
The Aleutian low and Greenland low have deepened.
The subtropical ridge in the Southern hemisphere has recovered after
its December extreme.
Pressure anomalies for past month (below)
The anomaly pressure pattern highlights these differences.
The 1015 isobar has expanded to cover NZ.
Ridge axis seems to have moved north of Tasmania.
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/
Cyclone RAE caused some crop damage in Fiji.
Cyclone SERU went over mainly open water between Vanuatu and Fiji.
ALFRED is a slow mover currently going south and MIGHT go inland near
Brisbane mid-week.
Cyclone BIANCA formed off northwestern Australia. Cyclone Garance
started near Réunion as Cyclone Honde threatened southern Madagascar.
WEATHER ZONES
Rain accumulation this week from Windy.com shows heavy rain from Tonga
to Niue and with ALFRED.
Wind accumulation this week from Windy.com
The wind accumulation shows trails of wind mapped out by ALFRED and L1
LOWS and HIGHS
Low L1 now near Fiji is the remains of SERU and is moving slowly east
.
ALFRED is moving slowly south and MIGHT go inland late in the week
near Brisbane.
HIGH H1 now over North Island is moving off to the ESE.
This allows an active cold front to travel NE over NZ on Monday and
Tuesday and then form a Low L2 near Chathams on Wednesday with a
strong SE flow over NZ.
That should be followed by H2 now in Australian Bight and travelling
east across South Tasman mid-week then onto NZ for the weekend.
Low L3 should form near Bass Strait on Wednesday, followed another
HIGH H3.
Low l4 should remain slow-moving over inland Australia, but the
monsoonal trough is rather dry this week.
Gulf of Panama: A useful NE flow for starters
Galapagos: A low has formed to the SW and there is a CONVERGENCE ZONE
with squalls over the group and another between 6 and 9S from 95W to
106W
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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 2 March 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 at
youtu.be/R1DQQPwkNYE
During February the climate modellers agreed the Pacific is in ENSO
neutral territory. The MJO travelled across the South Pacific during
the month activating the South Pacific Convergence zone and forming a
series of 7 tropical lows with 3 of them becoming cyclones in the last
week.
The 500hPa heights and anomalies shows last month's typical ridge
/trough pattern, after a troughy January.
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 fading blue tongue along the central Pacific shows we are in ENSO
neutral territory.
Average isobars for past month (below)
From http://www.psl.noaa.gov/map/images/fnl/slp_30b.fnl.html
The Aleutian low and Greenland low have deepened.
The subtropical ridge in the Southern hemisphere has recovered after
its December extreme.
Pressure anomalies for past month (below)
The anomaly pressure pattern highlights these differences.
The 1015 isobar has expanded to cover NZ.
Ridge axis seems to have moved north of Tasmania.
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/
Cyclone RAE caused some crop damage in Fiji.
Cyclone SERU went over mainly open water between Vanuatu and Fiji.
ALFRED is a slow mover currently going south and MIGHT go inland near
Brisbane mid-week.
Cyclone BIANCA formed off northwestern Australia. Cyclone Garance
started near Réunion as Cyclone Honde threatened southern Madagascar.
WEATHER ZONES
Rain accumulation this week from Windy.com shows heavy rain from Tonga
to Niue and with ALFRED.
Wind accumulation this week from Windy.com
The wind accumulation shows trails of wind mapped out by ALFRED and L1
LOWS and HIGHS
Low L1 now near Fiji is the remains of SERU and is moving slowly east
.
ALFRED is moving slowly south and MIGHT go inland late in the week
near Brisbane.
HIGH H1 now over North Island is moving off to the ESE.
This allows an active cold front to travel NE over NZ on Monday and
Tuesday and then form a Low L2 near Chathams on Wednesday with a
strong SE flow over NZ.
That should be followed by H2 now in Australian Bight and travelling
east across South Tasman mid-week then onto NZ for the weekend.
Low L3 should form near Bass Strait on Wednesday, followed another
HIGH H3.
Low l4 should remain slow-moving over inland Australia, but the
monsoonal trough is rather dry this week.
Gulf of Panama: A useful NE flow for starters
Galapagos: A low has formed to the SW and there is a CONVERGENCE ZONE
with squalls over the group and another between 6 and 9S from 95W to
106W
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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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