COGOW etc for passage planning - and why you need them

11:35 PM Fri 17 Jul 2009 GMT

'cogow' .

When passage planning, one needs all the help one can get to choose the right time to go, and the right winds to depart.

Next time you're planning a passage, try these websites for the help the can give you. Here Lee Bruce, of OceanMet (a division of Tactical Weather LLC) tells you why these sites can improve your planning:

Traditional climatology records are based on decades of data, and can be useful as long as we understand the limitations. Because the data are averaged over long periods, we can lose a feel for the variations that may occur. Extreme events are masked, so we don't know how bad it could be in a worst-case scenario.

The problem is compounded over vast ocean areas because-until recently-there has not been a reliable data collection process. Ship reports are sparse and tend to be clustered near traditional trade routes. Extreme events may go under-reported because the crew is busy dealing with the problem at hand, and does not have the opportunity to report conditions.

But for several years now, a product has been available that uses sensors on a satellite to measure the wind over open ocean surfaces. The system (reading near real-time data collected by NASA/JPL's SeaWinds Scatterometer aboard the QuikSCAT satellite) scans the oceans twice each day, as the satellite revolves around the earth from pole to pole. Due to the footprint of the sensor, there is a shifting data gap with each pass that is widest near the equator. But overall, the information gathered is very good, and is a tremendous advantage over any previous data-gathering method.

Two of my favorite web sites that use QuickSCAT data can be used to review overall wind regimes for a passage. You can check wind observations on a daily/weekly/monthly basis for a particular year, or averaged over five years for a particular month. Each site has its benefits, and I recommend using both for passage planning.

Oregon State University has a site (above) that shows monthly averages over a five year period, and also presents a wind rose to show the wind distribution.

numbat.coas.oregonstate.edu/cogow/index.html

Remote Sensing Systems presents QuickSCAT data (below) as a monthly average for a specific year, a weekly average, or as raw daily data:

www.ssmi.com/qscat/scatterometer_data_monthly.html

quikscat - .. .

If you need professional assistance planning a more than usually difficult route you can contact Lee at:

mail [at] tacticalweather.com

by Lee Bruce

Click on thumbnails to enlarge and find more photos:

Newsfeed supplied by

#News #Cruising

Nearby
North Head, NSW	5 kn W
Little Bay, NSW	6 kn NW
Cronulla, NSW	4 kn SSW
Windiest in Australia
Mount Wellington, TAS	34 kn WSW	-0°
Most Windless in Australia
Tewantin, QLD	Calm	17°
Hottest in Australia
Bradshaw - Angallari Valley (Defence), NT	6 kn E	27°
Coldest in Australia
Mount Wellington, TAS	34 kn WSW	-0°
Wettest in Australia
Cabramurra, NSW	38.0 mm

Gps and Speed talk
	September Virtual Slalom at ka72.com
	GPS Replays
	Make it Personal - track segment colours
	Delta fin
Foiling
	Decoding Reflexed Airfoils
	Front foil size vs wind speed - building my quiver
	2026 Starboard windfoil or the 2026 ZFins Slalom/Race Foil?
	Starboard Ucs durability
Wave sailing
	Mana Island - Fiji
Gear Reviews
	Severne 2027

COGOW etc for passage planning - and why you need them

Live Weather

Nearby

Windiest in Australia

Most Windless in Australia

Hottest in Australia

Coldest in Australia

Wettest in Australia

Windsurfing Forum Topics

Buy & Sell

2019 SIC Rs

2025 North Dock Starter

2022 F-One Bandit S3

PPC Surge Mk 2

2019 Cabrinha Switchblade

2024 North Vert 30L

2025 Vevor Trolley

Weather

Activities

About

Other

Support