Gulf Harbour Radio
The following papers cover a wide variety of weather topics. They have been written by David in response to the many questions that have arisen from cruisers over the years of our broadcasts. Hopefully with study, they will enable cruisers to make good choices when planning a passage, or choosing a sheltered anchorage.
You are welcome to copy them but if you republish please be aware they are copywrited so include the writers name and contact details.
You are welcome to copy them but if you republish please be aware they are copywrited so include the writers name and contact details.
Lows on the back of a High |
This is a somewhat common event in the SW Pacific and is important to watch when considering a passage to the Islands as it can affect the passage route. This explains why it happens.
|
Sailing from NZ to the Islands |
SV Chameleon looks at the following factors when considering when to leave NZ. The crew does not like a rough passage so sea conditions are as important as wind direction if she is going to come next time! Although there can be late April opportunities we do not leave before May 1st due to insurance considerations.
|
Sailing to NZ |
The factors that Chameleon considers before a passage. Those she likes - and those she does not!
Also included are definitions of all the weather terms used by David on Gulf Harbour Radio's weather broadcasts, and hints for how to interpret weather products. |
Weather for the Yachtsman |
A more detailed discussion of marine weather terminology, definitions, rules of thumb and the use of Grib files for forecasting. This is not too technical and is designed to help the user wade through the sometimes confusing terminology from various forecasting sources. It also gives some hints as to how to best use data obtained from the Gribs.
|
Passage - New Caledonia to NZ |
Includes from Vanuatu.
The following are some ideas for Chameleon to consider when planning our passage. These are based on averages only plus experience. Reality may be vastly different because the speeds and shapes of travelling surface features change and can defeat the following concepts of averages. |
Passage - Tonga to NZ |
Chameleon's ideas for a direct or via Minerva passage.
|
500hpa Analysis :
|
Listeners to Gulf Harbour radio will know that I always start the weather update with a discussion of the upper levels. An understanding of this is really important if you want to work out what is happening with the weather . Included is how to get the upper levels . There is a good web site reference at the end of the paper.
|
The MJO cycle |
The MJO or Madden- Julien Oscillation is a wave oscillation travelling eastward around the globe on an average of 40 days. It was discovered by Madden and Julian in 1971 who called it the 40 to 50 day oscillation. Cycles have varied from 30 to 60 days. The MJO directly affects the weather for cruising yachts. When the MJO is overhead the yacht will expect light to heavy rain and squally conditions.
|
Trade Wind Surge |
This feature is common in the tropics so it is important to understand how it occurs and how to look for it.
|
Tropical Weather Systems - a review |
A somewhat detailed summary of some significant tropical synoptics and events which can influence the weather encountered by yachts in the South Pacific. An overriding influence in the tropics and subtropics is the Subtropical Jet (SJT). It’s a semi-permanent feature near the poleward margin of the tropics and its strong baroclinic field, especially in winter, can and does supply energy for weather disturbances in low latitudes.
|
Tropical Cyclones IN THE SOUTHWEST PACIFIC |
A Tropical Cyclone in the SW Pacific is a cyclonic warm core system with winds of 34 knots or greater, whereas a Hurricane or Typhoon has winds of 64 knots or greater. BoM rates tropical cyclones (TC) by a scale of 1 to 5. This scale was established for local conditions and is similar to the Saffir Simpson Scale used in much of the world.
|
Weather products in the SW Pacific |
There is a lot of information available from the Met offices in NZ, Fiji and New Caledonia but much of what is available is too large to download when on passage. Max on SV Y2K has reduced these to a workable size. These are summarized in https://www.y2ksail.com/meteo.html or
.../meteo-link.html that has all links visible |
Satellite Imagery Interpretation |
Satellite imagery is a useful source of analysis for the oceanic regions in the southern hemisphere, particularly in data sparse areas. The paper is a compilation from various sources to help the beginning user interpret images from polar orbiting satellites. This guide is not all encompassing but should provide enough information of the basics to enhance the interpretation.
|
© 2021 Gulf Harbour Radio | Website by OPDM