Bob Blog 30 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 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.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>