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
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>