2009 Ocean Remote Sensing Group, Johns Hopkins University Applied Physics Laboratory
Tuesday, 19 May 2009 00:00 GMT
To this point the fleet has been heading east-northeast towards the first scoring gate and the ice exclusion zone. The winds increased on Sunday, topping 20 knots for almost 24 hours, as the pressure gradient built between a cold front to the west and a large zone of high pressure to the east. On Monday, high pressure shifted slowly south towards the fleet as the front stalled, leaving lighter left shifted (SSE’ly) winds for the afternoon and evening.
Looking ahead, the fleet is expected to cross the scoring gate sometime this morning (Tuesday) in light to moderate S’ly winds. Given no restriction, the fastest route to Galway would then take the fleet north, tracking around the northern periphery of the high before hooking into the next area of low pressure. Unfortunately this year’s artic spring has produced many ice bergs, some of which have drifted as far south as 43N. To keep the fleet safe from the ice danger, there is an aggressive ice exclusion zone to the east of the scoring gate.
Thus the next 24 hours should be interesting, as the pressure to be first to the scoring gate weighs against the long term strategy of the leg. The teams to the north have the advantage (in terms of wind speed and direction) to reach the scoring gate. However, with light to moderate S’ly winds expected to build slowly around the western periphery of the high, all the teams will find themselves beating upwind after they cross the scoring gate. Thus the teams to the south will have the advantage when it comes to getting around the ice exclusion zone. They may have lighter winds but they will have a better wind angle and less total distance to sail.
Beyond the ice exclusion zone you can expect the fleet to head north into the notorious North Atlantic Storm track. At the moment, it looks like the next area of low pressure is developing along the stalled front to the north and west of the fleet. As this low tracks east, the fleet can hope to hook into the strong W’ly winds around the southern periphery of the low.
For now it looks like the fast and cold conditions will continue all the way to Galway; with close competition keeping everyone on their toes.
Jennifer Lilly Race Meteorologist