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 13 October 2024
Southwest Pacific Tropical Cyclone Outlook – October 2024
The NIWA and MetService assessment of tropical cyclone activity
indicates six to 10 named TCs could occur in the Southwest Pacific
from November 2024-April 2025.
The NIWA and MetService assessment of tropical cyclone (TC) activity
for the coming season indicates normal to below normal activity.
(Tropical cyclones are categorised in strength from 1 to 5, with 5
being most intense. Tropical cyclones that reach category 3 or higher
are classified as severe, with mean (10 minute) wind speeds of at
least 119 km/h.)
Six to 10 named TCs could occur in the Southwest Pacific from November
2024-April 2025. The long-term average number of named TCs per season
is around nine.
TCs have a significant impact across the Southwest Pacific, with the
season starting in November and lasting through April. For the coming
season, significant differences are expected between the western and
eastern halves of the basin.
The risk of impact from a TC is expected to be higher near the Coral
Sea, Solomon Islands, and Papua New Guinea, as illustrated in the
following map. Normal to reduced risk is anticipated in the central
and eastern part of the basin.
Watch the NIWA video at youtu.be/Jdy9lJ2tOv4
Tropical cyclone outlook summary for New Zealand
On average, at least one ex-TC passes within 550 km of New Zealand
each year. This season, the risk is considered normal-elevated.
If an ex-TC tracks close to the country, there is a near-equal
probability of it tracking to the east or west of the North Island
based on historical climate data.
Two out of five analogue years considered in this outlook had at least
one ex-TC passing within 550 km of the country.
Analogue years suggest that a decaying ex-TC entering the New Zealand
region could affect maritime and coastal areas around the North
Island, but an interaction with the South Island cannot be ruled out.
El Niño-Southern Oscillation outlook
As of early October 2024, sea surface temperatures across the eastern
and central equatorial Pacific Ocean are below average and close to La
Niña thresholds.
Atmospheric circulation patterns related to ENSO over French Polynesia
and northern Australia indicate neutral ENSO conditions as of early
October 2024.
Oceanic and atmospheric forecasts for ENSO suggest La Niña, of
weak-to-moderate intensity, has a 60-70% chance of emerging by
December 2024. La Niña conditions, should they develop, are likely to
persist through the back half of the TC season in February-April.
TROPICS
Hurricane Milton pummelled Florida's central Gulf Coast as a
Category-3 storm and the fifth hurricane to make landfall in the U.S.
this year. The storm brought storm surges, wind damage and record
rainfall.
• Hurricanes Kirk and Leslie churned the open Atlantic Ocean.
• Typhoon Krathon left two people dead after striking southern Taiwan.
• Tropical Storm Ancha formed in the Indian Ocean out of season (South
Indian Ocean cyclone season nominally open mid-November).
WATHER ZONES
The wind accumulation shows several zones of strong wind this week,
which cruising yachts should avoid this week
The South Pacific Convergence zone is building and shifting southward
across Vanuatu next few days. It is expected to form a Low L3 near
Tanna late on Wednesday and this Low should then travel quickly
southeast to be around 1004 over Minerva on Thursday and then quickly
away. AVOID. Associated trough should cross Tonga on local Thursday
with gusty northly winds.
Travelling to Australia: There is a small squash zone of 25kt SE winds
in the Coral Sea around Tuesday maybe Wednesday, and a south to
southeast wind change from a passing trough at Brisbane around
Thursday, otherwise it looks OK.
HIGHS and LOWS
HIGH H1 has been blocking movement and remains near 35S to south of
Tahiti.
Low L1 is crossing central NZ on Monday then expected to travel east
along about 40S.
A High currently in the central Tasman Sea is expected to travel NE
and fade near Norfolk Island
Low L2 is expected to form well offshore of Sydney on Monday then
travel NE following a High, and then fade away on Friday., leaving a
lull of light winds over New Caledonia for the weekend.
HIGH H2 is expected to travel into the South Tasman Sea 1032 by late
Tuesday then travel onto central NZ, maintaining an easterly flow
between Northland and the tropics this weekend and early next week.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about your voyage, then check
metbob.com to see what I offer.
Or Facebook at /www.facebook.com/metbobnz/
Weathergram with graphics is at metbob.wordpress.com
(subscribe/unsubscribe at bottom).
Weathergram archive (with translator) is at
weathergram.blogspot.co.nz.
Contact is bob@metbob.com or text 64277762212.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
13 October 2024
06 October 2024
Bob Blog 6 October
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 6 October 2024
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/aB6kMuWLNKQ
The main pattern for September was a migratory HIGH travelling east
along around 25 to 35S followed by a trough or two, sometime three
with disturbed westerly wind south of 40S.
The tropics in the South Pacific were quiet.
Sea Surface temperature anomalies from psl.noaa.gov/map/clam/sst.shtml
The Kuroshio current is now retesting after crossing the entire north
pacific last month.
Will someone show the latest North Atlantic Sea surface map to the
candidates for US leader
as one of them seems to think this month's cyclones are abnormally
late.
And the weaker cool tongue along the Pacific equator os a sign that
the incoming La Nina is stuttering.
Average isobars for past month
During September the Monsoon spread east across Asia.
Being an equinoctial month the subtropical ridges in both hemispheres
strengthened.
Pressure anomalies for past month (below)
The anomaly pressure pattern for September shows ridging over the
North Sea and troughing over South America, a total reversal of last
month.
The southern 1015 line has stayed from about Tasmania to Gisborne.
The northern 1015 line has shifted to south of Darwin. a sign that
winter is over there.
TROPICS
Around 200 people perished in flooding and other storm-related
disasters as Hurricane Helene ravaged Florida and other parts of the
southeastern United States. .
Hurricane John caused at least five deaths as it made a second
landfall in Mexico's Guerrero state.
. Hurricanes Isaac and Joyce, and Tropical Storm Kirk, churned the
Atlantic.
.LESLIE is in mid Atlantic and MILTON ins in the Gulf of Mexico.
. Typhoon Krathon lashed Taiwan.
. Typhoon Jebi skirted northeastern Japan.
. ANCHA is the first named storm in the southern hemisphere after the
equinox (the South Indian Ocean cyclone season has a nominal start of
15 November0.
WEATHER ZONES
The wind accumulation shows the light wind area associated with H1 and
some weak squash zone around the Cook Islands, along with gaps between
them
It also shows lots of wind NE of NZ later this week from L2, but a gap
of OK winds emanating north from Northland, NZ.
The South Pacific Convergence zone is sitting over Solomon Islands and
extends to Rotuma and Samoa and then to the southeast across Southern
Cooks. A trough and low L2 tis expected to form over Vanuatu on
Thursday and then travel SE to be pass by eastern North Island on
Friday /Saturday 11/12 Oct. Avoid.
Travelling to Australia: Looks OK this week, but for a southerly
change at Brisbane on Wednesday, and another over the weekend and
southerly swells to 3m as north as 25S on Monday 14 Oct. SPCZ might
start shifting south next week across Vanuatu.
HIGHS and LOWS
HIGH H1 has been blocking movement and remains near 35S to south of
Tahiti.
Low L1 is zipping quickly along 50S passing by southern NZ on
Wednesday. NZ has a showery NW flow on Monday/Tuesday, a squally
Wednesday, a southerly flow for Thursday then mainly sunny with a
passing High H2 over centre of NZ by Friday.
L2 forms between Norfolk and Raoul near 30S on Friday and deepens and
it passes by eastern North Island on Saturday. Avoid.
For New Caledonia: The trough associated with L2 is expected to bring
a southerly change late Tuesday. The HIGH H2 moving along 30S into the
Tasman Sea after L2 is expected to develop a squash zone of strong SE
winds near New Caledonia and in the Coral Sea from Wednesday to
Saturday. Avoid.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about your voyage, then check
metbob.com to see what I offer.
Or Facebook at /www.facebook.com/metbobnz/
Weathergram with graphics is at metbob.wordpress.com
(subscribe/unsubscribe at bottom).
Weathergram archive (with translator) is at
weathergram.blogspot.co.nz.
Contact is bob@metbob.com or text 64277762212.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Disclaimer: Weather is a mix of pattern and chaos; these ideas are
from the patterned world.
Compiled Sunday 6 October 2024
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/aB6kMuWLNKQ
The main pattern for September was a migratory HIGH travelling east
along around 25 to 35S followed by a trough or two, sometime three
with disturbed westerly wind south of 40S.
The tropics in the South Pacific were quiet.
Sea Surface temperature anomalies from psl.noaa.gov/map/clam/sst.shtml
The Kuroshio current is now retesting after crossing the entire north
pacific last month.
Will someone show the latest North Atlantic Sea surface map to the
candidates for US leader
as one of them seems to think this month's cyclones are abnormally
late.
And the weaker cool tongue along the Pacific equator os a sign that
the incoming La Nina is stuttering.
Average isobars for past month
During September the Monsoon spread east across Asia.
Being an equinoctial month the subtropical ridges in both hemispheres
strengthened.
Pressure anomalies for past month (below)
The anomaly pressure pattern for September shows ridging over the
North Sea and troughing over South America, a total reversal of last
month.
The southern 1015 line has stayed from about Tasmania to Gisborne.
The northern 1015 line has shifted to south of Darwin. a sign that
winter is over there.
TROPICS
Around 200 people perished in flooding and other storm-related
disasters as Hurricane Helene ravaged Florida and other parts of the
southeastern United States. .
Hurricane John caused at least five deaths as it made a second
landfall in Mexico's Guerrero state.
. Hurricanes Isaac and Joyce, and Tropical Storm Kirk, churned the
Atlantic.
.LESLIE is in mid Atlantic and MILTON ins in the Gulf of Mexico.
. Typhoon Krathon lashed Taiwan.
. Typhoon Jebi skirted northeastern Japan.
. ANCHA is the first named storm in the southern hemisphere after the
equinox (the South Indian Ocean cyclone season has a nominal start of
15 November0.
WEATHER ZONES
The wind accumulation shows the light wind area associated with H1 and
some weak squash zone around the Cook Islands, along with gaps between
them
It also shows lots of wind NE of NZ later this week from L2, but a gap
of OK winds emanating north from Northland, NZ.
The South Pacific Convergence zone is sitting over Solomon Islands and
extends to Rotuma and Samoa and then to the southeast across Southern
Cooks. A trough and low L2 tis expected to form over Vanuatu on
Thursday and then travel SE to be pass by eastern North Island on
Friday /Saturday 11/12 Oct. Avoid.
Travelling to Australia: Looks OK this week, but for a southerly
change at Brisbane on Wednesday, and another over the weekend and
southerly swells to 3m as north as 25S on Monday 14 Oct. SPCZ might
start shifting south next week across Vanuatu.
HIGHS and LOWS
HIGH H1 has been blocking movement and remains near 35S to south of
Tahiti.
Low L1 is zipping quickly along 50S passing by southern NZ on
Wednesday. NZ has a showery NW flow on Monday/Tuesday, a squally
Wednesday, a southerly flow for Thursday then mainly sunny with a
passing High H2 over centre of NZ by Friday.
L2 forms between Norfolk and Raoul near 30S on Friday and deepens and
it passes by eastern North Island on Saturday. Avoid.
For New Caledonia: The trough associated with L2 is expected to bring
a southerly change late Tuesday. The HIGH H2 moving along 30S into the
Tasman Sea after L2 is expected to develop a squash zone of strong SE
winds near New Caledonia and in the Coral Sea from Wednesday to
Saturday. Avoid.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
If you would like more details about your voyage, then check
metbob.com to see what I offer.
Or Facebook at /www.facebook.com/metbobnz/
Weathergram with graphics is at metbob.wordpress.com
(subscribe/unsubscribe at bottom).
Weathergram archive (with translator) is at
weathergram.blogspot.co.nz.
Contact is bob@metbob.com or text 64277762212.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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