Bob Blog

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 28 Feb
Satellite view of recent rain
The Tropical rain Measuring Mission provided us with recent rain
measurements via satellite that could be viewed on Goggle earth via kml
until the mission was decommissioned in 2018.
It has been replaced by the GPM or Global precipitation Mission and data
from this satellite, sadly not available as a kml file, can be gleaned from
gpm.nasa.gov/data/visualization/global-viewer, with a choice of 7day, 24
hour or 30 minute timesteps.
Sadly, there is no latitude/longitude grid.
This data is also available from the nasa viewer website at
worldview.earthdata.nasa.gov/, in the Layer picker click "+Add layers"
(bottom left) and search for "GPM" or "IMERG" then select Rain rate
(Ascending) and Rain rate (Descending), then close the selection windows to
view the data.Sadly no coastal boundaries or lat/long grid.

The Tropics
The latest cyclone activity report is at tropic.ssec.wisc.edu and Tropical
Cyclone Potential is from http://www.ssd.noaa.gov/PS/TROP/TCFP/index.html
TC MARIAN is moving southwest across the South Indian Ocean.
A strong monsoonal trough lies across the South Pacific with several small
lows brining squally showers but these have a low likelihood of growing
further. There is a Tropical Depression 99P in the Coral Sea that has a high
potential of this system becoming a Tropical cyclone by Monday.

WEATHER ZONES
SPCZ=South Pacific Convergence zone.
SPCZ is stretching southeast from Solomons to Tonga. TC is expected in the
Coral Sea.
A passing trough extends to southeast of French Polynesia and this may form
a low near the Austral Group by local Thursday that should travel off to the
South.
The rain accumulation map is starting to show a line of showers at 5S to
south of the Galapagos. This is the start of an annual system that is
sort-of-a-mirror-image of the ITCZ, due to the noon day being directly
overhead 5 degrees South latitude from around 5 to 10 March.

Subtropical ridge (STR)
HIGH 1022 east of South Island is expected to travel east along 47S and
build to over 1030 near 140West.
Next HIGH is expected to travel east across Tasmania on Saturday 6 March and
then travel northeast across the Tasman Sea and onto North Island early next
week.

NZ/Tasman troughs
Low 1005 in Tasman Sea is expected to travel off to the south. Another Low
is expected to form east of Tasmania on Monday and deepen to below 984 as it
passes by Campbell island on Wednesday with a few days of strong westerly
flow over NZ, turning SW on Thursday and Friday.
Start of America's Cup in Auckland has been delayed by a COVID lockdown.

Panama to Galapagos/Marquesas
Good northerly winds in Panama this week, but these may become light and
variable by mid-March. Wind flow over Galapagos is expected to turn to be
from the south from mid-arch. Current is expected to peel off to the north
of Galapagos, so way to go to Marquesas this week is via 3N 92W.
mailto:bob@metbob.com