Tuesday, 31 August 2010

HSBC Premier Coastal Classic: Weather Stats Favor Southerly

Weather statistics from NIWA. Supplied image.

by Zoe Hawkins

Historically, there is just a one in a hundred chance of optimal strong South-Easterlies during the month of October, according to data provided by the National Institute for Water and Atmospheric Research (NIWA). But there is a 45% chance that the wind will come from the South-West, which is the second best scenario for sailors seeking a fast run in the HSBC Premier Coastal Classic.

While a South-Easter is rare, it gives the boats optimal wind direction for the entire 119 nautical mile yacht race. A South-Wester drives them as far as Cape Brett, before sailing into headwinds for the last miles to the finish line.

An analysis of hourly mean wind speed and direction data from the Auckland region since 1980 shows that historically, there is a 27% chance of winds being less than 8 knots from any direction. There is a 6.5% chance the fleet will encounter a light South-Easter (with winds less than 15 knots), and a 29% chance of a light South-Westerly. There is a 16% chance of a stronger South-Wester (winds more than 15 knots).

For those that enjoy upwind racing the odds are still reasonable: a 34% chance of a light Northerly quadrant wind (less than 15 knots), and an 11% chance of a stronger Northerly quadrant wind during the month of October.

“These are mean wind speeds, so gusts can be 50% higher,” explains Georgina Griffiths, NIWA. “And bear in mind that the NIWA seasonal outlook indicates a La Nina event to be in place by about September. Northerly or easterly winds are slightly more common during La Nina, than otherwise might be".

Longrange forecaster Ken Ring anticipates that Friday will offer calm, light North-Easterlies and fine weather. “Saturday may also be relatively uneventful, with onshore light winds, probably from the northeast or southeast, with a developing depression serving cloud and brief showers during daylight hours but with night skies clearing, together with a wind drop. Sunday, winds stir into life with a W/SW change, clearer skies, moderate winds, and a chop on the open water. Monday brings variable winds, strengthening, but these windier conditions may be too late in the race for any records to be broken.”

“Only time can tell what will happen but it’s interesting to speculate,” says Jon Vincent of the New Zealand Multihull Yacht Club. “While a South-Easter is great for an exciting record setting race, for most competitors the spirit of the HSBC Premier Coastal Classic is about taking part, going as fast as you can, and having a great time, and for that we only ask for it to be warm and sunny.

Race sponsor Predictwind.com will issue an official, detailed race forecast on the eve of the race.

The supermaxi Alfa Romeo broke a thirteen-year record drought when it set a new overall record last year, completing the race in 6 hours and 43 minutes, but Split Enz remains the fastest multihull to ever finish the race with a record set in 1996 of 7 hours and 20 minutes.

The HSBC Premier Coastal Classic starts from 10am on Friday 22 October off Devonport Wharf in Auckland, and finishes off Russell Wharf in the Bay of Islands. As well as title sponsor HSBC Premier, sponsors include Musto, Safety at Sea, Mt Gay Rum, Steinlager, the Duke of Marlborough Hotel, Railblaza Ltd, Jucy, PredictWind, SailNZ and Snitch GPS. Trade-A-Boat and the Sunday Star Times are media partners, and Southern Pacific Inflatables, Yamaha Motor NZ, and Dirty Dog Sunglasses, are providing spot prizes.

HSBC Premier Coastal Classic