Underway - Pacific Crossing Notes: A Sailor's Guide to the Coconut Milk Run - page 116

• M 0.5 : Grid spacing in degrees; valid values are 0.25, 0.5, 0.75, 1.0, 1.25, 2.5
• D 10 : remains the same for every request
• P courant : remains the same for every request
• G 24 48 72 96 120 144 168 192 216 240 : forecast times in hours
• C bzip2 : file compression method
• s 2.1.3 : remains the same for every request
• @mto@reqt@fin@ : always the same

The model outputs seem to be updated once a week. Depending when you send your re-
quest in that weekly cycle, you may receive a note in the response: “incomplete extrac-
tion/extraction partielle.” You will, however, still receive the data for the remaining por-
tion of the forecast period.

We found the model surprisingly accurate in the South Pacific. The accuracy does seem to
degrade toward the end of the weekly forecast horizon (at least in areas where eddies and
currents move significantly over a week). However, the first seventy-two to ninety-six
hours were often strikingly accurate.

Footnote 1: Lifted Index is an indicator of the stability of the atmosphere's layer-
ing. A positive value indicates stable conditions, while negative values indicate in-
stability. CAPE is an indicator for available convective energy in the atmosphere.
High CAPE (>2000 Joule/kg) in combination with a negative Lifted Index points
towards heavy thunderstorms with very squally conditions which may not be re-
flected in the wind speed forecast.
[#1] http://svsoggypaws.com/files/JimCorenman-SouthPacificLetters.pdf
[#2] http://www.pangolin.co.nz/downloads/weather_for_the_yachtsman_2008.pdf
[#3] http://www.pangolin.co.nz/jetsam-index
[#4] http://boatbooks.co.nz/weather.html#23104
[#5] http://www.oceannavigator.com/Ocean-Voyager-2012/Coconut-Milk-Run-weath-

[1]

er/
[#6] http://weather.noaa.gov/fax/marine.shtml
[#7] http://www.oceannavigator.com/March-April-2014/Weather-to-New-Zealand/
[#8] http://weather.noaa.gov/fax/marine.shtml
[#9] http://www.metservice.com/maps-radar/maps/southwest-pacific
[#10] http://www.bom.gov.au/marine/

http://metvuw.com/forecast/fore-
cast.php?type=rain&region=spacific&noofdays=7

[#11]