Thursday, March 08, 2012

Weather Updates

Last Sunday saw a significant increase in wind speed and a sudden change in wind direction at the time when many sea kayakers may well have been out on the water.  With the assistance of John Searson from the States of Jersey Meteorological Department it has been possible to analyse what took place and to see if any lessons could be learnt to improve the safety of those among us who operate on the sea.
At 05.30Z on Sunday morning the shipping forecast was upgraded from NW strong force 7 to NW gale 8.  Unfortunately the 06.00 shipping forecast had already been issued so any sea kayakers relying upon the shipping forecast alone would not have had the most up to date information.
At 09.30Z the gale warning was increased again to NW gale 8 gusting 50 knots this was a consequence of the winds which were being recorded in western Brittany.
If paddlers had been listening in on VHF Channel 82, Jersey Coast Guard then they should have heard the latest warnings issued by Jersey Met ensuring that they had the latest and most accurate information for their planning.  In addition if the group had access to a smart phone at around 11.00Z they might have been able to predict a significant shift in the winds direction.
10.00Z weather chart.  At this point winds in Jersey and Guernsey are still from the SE but a station in NW Brittany is recording NW gusting 54 knots.  The front is clearly approaching the Channel Islands from the west.
11.00Z.  Winds in Guernsey are from the NW but still from the SE in Jersey.  Any paddler who had access to this information would have known that there was going to be a sudden shift in wind direction and possible increase in wind speed.  A possible source of information is the AeroWeather app.  It provides current and precise information for airports around the world and amazingly is free.  If you are kayaking in waters close to airports then it can provide a significant amount of accurate data.
 12.00Z  The front has now passed through the Channel Islands but probably hasn't reached the southern area of the Cherbourg Peninsula.

By 11.41 the winds at St Helier Harbour was blowing 330 degrees at 34 knots gusting 43 knots, which is a very hazardous offshore wind, in contrast 40 minutes earlier the wind was onshore and gusting a maximum of 27 knots.  St Catherines, where the Jersey Canoe Club is based, was experiencing a mean wind speed of 38 knots, challenging conditions for any sea kayaker .
So what lessons are there to learn from Sunday?
1.) Always try to access the latest weather forecast.
2.) Try to use technology, VHF, phones etc, to be aware of any updates
3.) Be extra vigilant when strong winds with shifting directions are forecast.
4.) If you are in the Channel Islands respect the accuracy of the forecasts from Jersey Met.

Thanks once again to the Jersey Meteorological Department for the use of the maps and to John Searson for his input.

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