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 30 April 2023
A review of April 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/xgrzRC1Kbl8
April 2023 brought a mix of mobile lows and highs, along with a blocking
HIGH over Chathams late in the month feeding at atmospheric river onto
northern NZ.
The sea temperature continues to rise off Peru and the marine heatwave
around Tasmania to Chathams is relaxing. Seas have warmed north and south of
New Guinea. Little change elsewhere.
Average isobars for past month (below)
The greatest repositioning is happening over the Arctic with systems
relaxing, and the Antarctic with systems intensifying. The subtropical
ridges have shifted north.
Pressure anomolies for past month (below)
The anomaly pattern shows intense ridging over the Arctic and most of the
Antarctic.
Zooming into the NZ area
The subtropical ridge is drifting north over Australia and stronger in the
Indian Ocean.
The westerly flow in the 40s and 50s is lighter than normal south 0f New
Zealand.
TROPICS
All quiet on planet earth
WEATHER ZONES
The South Pacific Convergence zone SPCZ is expected to be well marked from
Solomon Islands to Samoa to Austral Islands and then with a tail to the
southeast.
HIGHS and LOWS
A BFH (big fat High) H1 is lingering over Chatham Island and should move
slowly east, with peak of 1039 hPa mid-week and with a squash zone on its
northern side between 18 and 25S.
Low L1 below 1000A in Tasman Sea west of Auckland tonight is travelling
quickly southwards and should move south of Southland on Tuesday.
Another low L2 is expected to cross Tasmania mid-week and stall near
Northland this weekend, finally followed by SW winds early next week,
perhaps.
Panama to Marquesas: There might be a period of northerly winds in Panama
gulf for starters mid-week. ITCZ is active to 2North. Doldrum of light winds
extends to 2South.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more detail for your voyage, then check metbob.com to see
what I offer.
Or Facebook at /www.facebook.com/metbobnz/
Weathergram with graphics is at metbob.wordpress.com (subscribe/unsubscribe
at bottom).
Weathergram archive (with translator) is at weathergram.blogspot.co.nz.
Contact is bob@metbob.com or txt 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
30 April 2023
16 April 2023
Bob Blog 16 April
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 16 April 2023
Climate change
We've done it.. Reached the warmest daily average ocean temperatures since
reliable world-wise measurements began in the 1980s:
(as recorded at climatereanalyzer.org/clim/sst_daily/) The previous warmest
was during the El Nino of 2016.
Review of the Cyclone Season
The Madden Julian Oscillation MJO is a burst of tropical energy that travels
from the Indian Ocean to the Pacific Ocean. It takes a week or two to travel
across each region and is associated with the formation of tropical
cyclones. However, this association doesn't work every time.
As a proxy for following the MJO a good parameter is outgoing longwave
radiation as measured by satellites. This is high with clear skies and
lowest when clouds are thickest. The chart is from the Climate Prediction
centre website cpc.ncep.noaa.gov/ shows three MJO events during the cyclone
season.
In New Zealand we will long remember the damage from Cyclone Gabrielle
(payouts so far of $0.9billion), Cyclone HALE and the many downpours. On
Valentine's Day 14 February a national state of emergency was issued in New
Zealand and there were 10 storm-related deaths.
And yet, as cyclone seasons go, the South Pacific region had been somewhat
average with 5 (maybe 6) named storms and just one Category 5 (Kevin) and
one Category 4 (Judy)
In the Australian region, by the numbers they had they had an average
cyclone season too with 10 named storms and two reaching Cat 5 (Darian and
Ilsa)
We can see no real association in the South Pacific region this year between
cyclone occurrence and MJO, but there is a plausible association in the
Australian region, especially during MJO2 and 3.
TROPICS
Tropical Cyclone ILSA grew to Cat5 before making landfall near Port Hedland
over NW Australia and took a couple of days to fade inland. There is an
interesting tropical depression tonight over Loyalty Islands, but it seems
to have missed its chance to become a tropical cyclone. This phase of MJO is
now moving across the Pacific.
WEATHER ZONES
South Pacific Convergence Zone SPCZ
A burst of convection is expected to travel east along the SPCZ across Fiji
and Tonga this week.
It has already produced a Low L1 that is expected to cross Iles des Pins on
Monday and then go south into the Tasman Sea later this week. It is expected
to form Low L3 that may deepen over Southern cooks by end of the week and
then go southeast this weekend. Avoid
Also in the tropics, a convergence zone is expected around Galapagos.
Zonal traffic in the mid-latitudes this week.
High Hi built to 1034 over Chathams Islands with a squash zone on its
northern side between H1 and L1. It is expected to travel off to the east.
Low L2 crossed Tasmania today and is expected to cross New Zealand on
Tuesday night and Wednesday following H1 and followed by H2.
Panama to Marquesas: Still getting northerly winds at Panama for departure.
Doldrums between 2north and 3 south with active showers around Galapagos.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more detail for your voyage, then check metbob.com to see
what I offer.
Or Facebook at /www.facebook.com/metbobnz/
Weathergram with graphics is at metbob.wordpress.com (subscribe/unsubscribe
at bottom).
Weathergram archive (with translator) is at weathergram.blogspot.co.nz.
Contact is bob@metbob.com or txt 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the
patterned world.
Compiled Sunday 16 April 2023
Climate change
We've done it.. Reached the warmest daily average ocean temperatures since
reliable world-wise measurements began in the 1980s:
(as recorded at climatereanalyzer.org/clim/sst_daily/) The previous warmest
was during the El Nino of 2016.
Review of the Cyclone Season
The Madden Julian Oscillation MJO is a burst of tropical energy that travels
from the Indian Ocean to the Pacific Ocean. It takes a week or two to travel
across each region and is associated with the formation of tropical
cyclones. However, this association doesn't work every time.
As a proxy for following the MJO a good parameter is outgoing longwave
radiation as measured by satellites. This is high with clear skies and
lowest when clouds are thickest. The chart is from the Climate Prediction
centre website cpc.ncep.noaa.gov/ shows three MJO events during the cyclone
season.
In New Zealand we will long remember the damage from Cyclone Gabrielle
(payouts so far of $0.9billion), Cyclone HALE and the many downpours. On
Valentine's Day 14 February a national state of emergency was issued in New
Zealand and there were 10 storm-related deaths.
And yet, as cyclone seasons go, the South Pacific region had been somewhat
average with 5 (maybe 6) named storms and just one Category 5 (Kevin) and
one Category 4 (Judy)
In the Australian region, by the numbers they had they had an average
cyclone season too with 10 named storms and two reaching Cat 5 (Darian and
Ilsa)
We can see no real association in the South Pacific region this year between
cyclone occurrence and MJO, but there is a plausible association in the
Australian region, especially during MJO2 and 3.
TROPICS
Tropical Cyclone ILSA grew to Cat5 before making landfall near Port Hedland
over NW Australia and took a couple of days to fade inland. There is an
interesting tropical depression tonight over Loyalty Islands, but it seems
to have missed its chance to become a tropical cyclone. This phase of MJO is
now moving across the Pacific.
WEATHER ZONES
South Pacific Convergence Zone SPCZ
A burst of convection is expected to travel east along the SPCZ across Fiji
and Tonga this week.
It has already produced a Low L1 that is expected to cross Iles des Pins on
Monday and then go south into the Tasman Sea later this week. It is expected
to form Low L3 that may deepen over Southern cooks by end of the week and
then go southeast this weekend. Avoid
Also in the tropics, a convergence zone is expected around Galapagos.
Zonal traffic in the mid-latitudes this week.
High Hi built to 1034 over Chathams Islands with a squash zone on its
northern side between H1 and L1. It is expected to travel off to the east.
Low L2 crossed Tasmania today and is expected to cross New Zealand on
Tuesday night and Wednesday following H1 and followed by H2.
Panama to Marquesas: Still getting northerly winds at Panama for departure.
Doldrums between 2north and 3 south with active showers around Galapagos.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more detail for your voyage, then check metbob.com to see
what I offer.
Or Facebook at /www.facebook.com/metbobnz/
Weathergram with graphics is at metbob.wordpress.com (subscribe/unsubscribe
at bottom).
Weathergram archive (with translator) is at weathergram.blogspot.co.nz.
Contact is bob@metbob.com or txt 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
09 April 2023
Bob Blog 9 April
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 9 April 2023
Climate change
With the help of Chatgpt (which did the data search for me) I was able to
quickly find the increasing threat of weather disasters in a few graphs.
The main agency studying weather risk seems to be UNDRR the UN office for
Disaster Risk Reduction
Their Global Assessment report GAM 2022 reports the increasing risk from
EM-DATA + CRED Database s
Passing comments is made that EM DAT data showed a large increase around
1990 due to the impact of the Internet. Note that in the past three years
the number of extreme temperature events have actually declined.these were
La Nina years.
This week the UNDRR have published their "Midterm review of the Sendal
Framework 2015-2030" with some interesting mortality graphs
These deaths are from weather +quake +Tsunami +volcano but do NOT include
the Covid 19 pandemic.
The peak in 2004 was from the Indian Ocean tsunami which killed at least
225,000 people across a dozen countries2008 was from Cyclone Nargis which
killed more than 138,000 in Myanmar. Generally, mortality is steady but for
those odd peaks but with a slight decreasing trend in spite of the
increasing number of disasters. This slight-decrease is due to improvements
in early warning systems, better disaster preparedness and response, and
increased access to healthcare. The slight increase in 2019 to 2022 in the
"per 100,000" graph is an artifact of the huge jump in excess mortality
around most of the world (not in New Zealand thanks to the team of 5
million) during the pandemic.
All this has been summed up in an article on Vox
www.vox.com/23150467/natural-disaster-climate-change-early-warning-hurricane
-wildfire
TROPICS
South Pacific Convergence Zone
The SPCZ is intensifying around PNG and may form a tropical low there late
in the week. It is of average intensity across northern Vanuatu to Samoa to
Tuamotu Island
A trough is expected to form in the Coral Sea on Monday and Tuesday then
cross New Caledonia mid-week and then go southeast past the south of Fiji
and Tonga. Avoid.
HIGHS and LOWS
Zonal traffic this week.
The Low that side-swiped norther NZ on Saturday in now east of the North
Island and expected to travel off to the east along 35S, pushing a High H1
that is south of Tahiti off to the east.
Broad multi-centred trough L2 now in the Tasman Sea with an active warm
front crossing the North Island tonight. L2 should finally cross central New
Zealand mid-week and then move off to the east.
The following High H2 is well to the south near 50S and expected to head
northeast towards Chatham Islands at end of the week.
By then Low L3 is expected to deepen over Lord Howe Island around Friday and
next weekend there should be a squash zone of NE winds from Tonga to New
Zealand between H2 and L3. AVOID.
Panama to Marquesas: Still getting northerly winds at Panama for departure.
But doldrums between 5N and 5S this week.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more detail for your voyage, then check metbob.com to see
what I offer.
Or Facebook at /www.facebook.com/metbobnz/
Weathergram with graphics is at metbob.wordpress.com (subscribe/unsubscribe
at bottom).
Weathergram archive (with translator) is at weathergram.blogspot.co.nz.
Contact is bob@metbob.com or txt 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the
patterned world.
Compiled Sunday 9 April 2023
Climate change
With the help of Chatgpt (which did the data search for me) I was able to
quickly find the increasing threat of weather disasters in a few graphs.
The main agency studying weather risk seems to be UNDRR the UN office for
Disaster Risk Reduction
Their Global Assessment report GAM 2022 reports the increasing risk from
EM-DATA + CRED Database s
Passing comments is made that EM DAT data showed a large increase around
1990 due to the impact of the Internet. Note that in the past three years
the number of extreme temperature events have actually declined.these were
La Nina years.
This week the UNDRR have published their "Midterm review of the Sendal
Framework 2015-2030" with some interesting mortality graphs
These deaths are from weather +quake +Tsunami +volcano but do NOT include
the Covid 19 pandemic.
The peak in 2004 was from the Indian Ocean tsunami which killed at least
225,000 people across a dozen countries2008 was from Cyclone Nargis which
killed more than 138,000 in Myanmar. Generally, mortality is steady but for
those odd peaks but with a slight decreasing trend in spite of the
increasing number of disasters. This slight-decrease is due to improvements
in early warning systems, better disaster preparedness and response, and
increased access to healthcare. The slight increase in 2019 to 2022 in the
"per 100,000" graph is an artifact of the huge jump in excess mortality
around most of the world (not in New Zealand thanks to the team of 5
million) during the pandemic.
All this has been summed up in an article on Vox
www.vox.com/23150467/natural-disaster-climate-change-early-warning-hurricane
-wildfire
TROPICS
South Pacific Convergence Zone
The SPCZ is intensifying around PNG and may form a tropical low there late
in the week. It is of average intensity across northern Vanuatu to Samoa to
Tuamotu Island
A trough is expected to form in the Coral Sea on Monday and Tuesday then
cross New Caledonia mid-week and then go southeast past the south of Fiji
and Tonga. Avoid.
HIGHS and LOWS
Zonal traffic this week.
The Low that side-swiped norther NZ on Saturday in now east of the North
Island and expected to travel off to the east along 35S, pushing a High H1
that is south of Tahiti off to the east.
Broad multi-centred trough L2 now in the Tasman Sea with an active warm
front crossing the North Island tonight. L2 should finally cross central New
Zealand mid-week and then move off to the east.
The following High H2 is well to the south near 50S and expected to head
northeast towards Chatham Islands at end of the week.
By then Low L3 is expected to deepen over Lord Howe Island around Friday and
next weekend there should be a squash zone of NE winds from Tonga to New
Zealand between H2 and L3. AVOID.
Panama to Marquesas: Still getting northerly winds at Panama for departure.
But doldrums between 5N and 5S this week.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more detail for your voyage, then check metbob.com to see
what I offer.
Or Facebook at /www.facebook.com/metbobnz/
Weathergram with graphics is at metbob.wordpress.com (subscribe/unsubscribe
at bottom).
Weathergram archive (with translator) is at weathergram.blogspot.co.nz.
Contact is bob@metbob.com or txt 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
02 April 2023
Bob Blog 2 April 2023
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 2 April 2023
REVIEW OF THE LAST MONTH (March 2023)
Here is a link to a YouTube clip giving an animated loop of the isobars and
streamlines in the South Pacific for March2023
https://youtu.be/sBcEaj_OL_E
Mar 2023 will be long remembered for Cyclone s JUDY and KEVIN delivering a
double whammy to Vanuatu at the beginning of the month.
The sea is getting warmer around Galapagos and remains cool near
equator/180. Sea temperature have returned to near normal around the South
Pacific Islands but remain warmer than normal in the North Pacific. A marine
heat wave continues around Fiordland to Chathams, the largest and most
intense on the planet. Little change elsewhere.
The greatest repositioning is happening over Greenland - the low that was
there last month has been shifted south to make way for a large High. The
norther subtropical ridge has weakened, and the southern has started its
annual shift to the north. Pressures have risen over Indonesia and PNG,
indicating that the Walker circulation is shifting eastwards.
The anomaly pattern also shows intense ridging from North Pacific across
Canada to Greenland.
Zooming in over Australasia, The subtropical ridge is drifting north and now
lapping onto the Australian south coast.
The 1010 isobar is moving north and almost across southern NZ.
TROPICS
A new phase of MJO is moving across the Indian Ocean and Cyclone HERMAN has
formed off the NW of Australia and is moving off to the west.
This MJO is expected to move into the Pacific Ocean over the next fortnight
but is also expected to be rather weak.
WEATHER ZONES
South Pacific Convergence Zone SPCZ
The SPCZ is rather weak northern Coral Sea to north of Fiji to Southern
Cooks and Astral Islands.
A subtropical low L2 is expected to form in the north Tasman Sea by midweek
bringing a squash zone to the Norfolk Island area . L2 then is expected to
move east past the north of NZ for Easter weekend. Avoid L2.
HIGHS and LOWS
HIGH H1 now in the mid Tasman sea is expected to travel east across the
North Island by mid -week and then off to the east along 35 to 30S
The trough that crossed NZ yesterday is expected to develop a low L1 east of
the North island on Monday that then travels off to the to southeast. This
system is expected to leave behind a canopy of frontal cloud over Norfolk
Island which seeds L2 by mid-week.
A transitional trough is expected to cross the South Island on Good Friday
followed by another High H2 on Saturday.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more detail for your voyage, then check metbob.com to see
what I offer.
Or Facebook at /www.facebook.com/metbobnz/
Weathergram with graphics is at metbob.wordpress.com (subscribe/unsubscribe
at bottom).
Weathergram archive (with translator) is at weathergram.blogspot.co.nz.
Contact is bob@metbob.com or txt 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Disclaimer: Weather is a mix of pattern and chaos; these ideas are from the
patterned world.
Compiled Sunday 2 April 2023
REVIEW OF THE LAST MONTH (March 2023)
Here is a link to a YouTube clip giving an animated loop of the isobars and
streamlines in the South Pacific for March2023
https://youtu.be/sBcEaj_OL_E
Mar 2023 will be long remembered for Cyclone s JUDY and KEVIN delivering a
double whammy to Vanuatu at the beginning of the month.
The sea is getting warmer around Galapagos and remains cool near
equator/180. Sea temperature have returned to near normal around the South
Pacific Islands but remain warmer than normal in the North Pacific. A marine
heat wave continues around Fiordland to Chathams, the largest and most
intense on the planet. Little change elsewhere.
The greatest repositioning is happening over Greenland - the low that was
there last month has been shifted south to make way for a large High. The
norther subtropical ridge has weakened, and the southern has started its
annual shift to the north. Pressures have risen over Indonesia and PNG,
indicating that the Walker circulation is shifting eastwards.
The anomaly pattern also shows intense ridging from North Pacific across
Canada to Greenland.
Zooming in over Australasia, The subtropical ridge is drifting north and now
lapping onto the Australian south coast.
The 1010 isobar is moving north and almost across southern NZ.
TROPICS
A new phase of MJO is moving across the Indian Ocean and Cyclone HERMAN has
formed off the NW of Australia and is moving off to the west.
This MJO is expected to move into the Pacific Ocean over the next fortnight
but is also expected to be rather weak.
WEATHER ZONES
South Pacific Convergence Zone SPCZ
The SPCZ is rather weak northern Coral Sea to north of Fiji to Southern
Cooks and Astral Islands.
A subtropical low L2 is expected to form in the north Tasman Sea by midweek
bringing a squash zone to the Norfolk Island area . L2 then is expected to
move east past the north of NZ for Easter weekend. Avoid L2.
HIGHS and LOWS
HIGH H1 now in the mid Tasman sea is expected to travel east across the
North Island by mid -week and then off to the east along 35 to 30S
The trough that crossed NZ yesterday is expected to develop a low L1 east of
the North island on Monday that then travels off to the to southeast. This
system is expected to leave behind a canopy of frontal cloud over Norfolk
Island which seeds L2 by mid-week.
A transitional trough is expected to cross the South Island on Good Friday
followed by another High H2 on Saturday.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more detail for your voyage, then check metbob.com to see
what I offer.
Or Facebook at /www.facebook.com/metbobnz/
Weathergram with graphics is at metbob.wordpress.com (subscribe/unsubscribe
at bottom).
Weathergram archive (with translator) is at weathergram.blogspot.co.nz.
Contact is bob@metbob.com or txt 64 277762212
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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