Group 2 is off and racing

The TransPac is a 2230 mile race from Long Beach Ca, to Diamond Head, the infamous backdrop to Waikiki Beach in Oahu. Since there are boats of all sizes competing, the race starts in 3 waves so that the different classes will finish at about the same general time. The slower boats started on Monday, the middle group started at 1pm this afternoon, and our group, of the fastest boats, will start on Sunday.

The dock talk this morning was abuzz about a weather forecast that is misbehaving... The more complicated and abnormal the better, I'd say...but apparently not all navigators and skippers would agree with me.

Let's have a look at the weather scenario for those that kicked off their 2009 TransPac this afternoon in the middle group;

In a 'normal weather scenario' the racers are pushed along by winds rotating, clockwise, around the Pacific High. Typically the center of the High is located directly west of northern California at a Longitude somewhere midway between Hawaii and the west coast of the USA. The weather maps in this scenario would look quite plane; a big 'H' out in the ocean with a bunch of concentric circles of increasing size around around the H. These rings depict the isobars (lines of equal pressure). The wind close to the H is light and the wind a couple rings out away from the H is nice for downwind surfing....thus the strategy is similar to running on a track. Would you rather be a slow runner running around a track on the inside lane one, or a fast runner on the outside lane six.

Most of the woes on the dock this morning were focused on this image:


Quite different from 'normal'; you can see a front that reaches up from Hawaii, an L where an H should be, and massive gaps between the isobar lines. This all indicates very little wind and very tricky conditions. The trade winds are, for all practical purposes, completely shut down. Furthermore, the 500 millibar analysis features a massive trough that is further complicating the 'normal' wind flow at the upper levels.

To look at a wind and pressure (MSLP) analysis (from the 12z GFS model run, plotted in Expedition), you can see that there is very little wind across the rhumb line (as noted by the black arc below). The areas of light wind are noted by the light purple regions, while the windy areas are in the green - to red side of the color spectrum.

You can see that the analysis changes quite a bit over the next 5 days. This is what the wind will look like about half way through the race for those that started today:You can see, by the blue regions just below the rhumb line, that some normalcy will return to the Eastern Pacific by the middle of next week.

So what will the game plan be for the boat starting today? I've heard that some boats are going to attempt a north route, while others will attempt a deep southerly route as their long range plan. While the boats started this afternoon in a coastal 12 knot sea breeze, the wind will quickly drop off to below 5 knots by around 3am tomorrow morning. It will most likely be a very slow morning for the fleet in group 2. I'd put my money on the boats that favor the southerly route coming out of the blocks. Those that press north will be rolling the dice and could likely find them selves adrift.

It's going to be a complicated couple days, but the race course is full of opportunity when the weather is this dynamic. Plenty of people asked for my opinion this morning before they left...the best advice that I could give was, "start on Sunday".

-Matt out
33 45.69N
118 11.62W