Friday, June 3, 2016

Preliminary Weather Update 3 June

Hello Bill and crew -

One of the overnight model runs looked much better for you regrading the second low with a track south of 40N and a weaker system through the weekend, then a turn to the north-northeast east of 30W early next week. This is only one model run, and I want to see the next run to see if this is consistent or not.

If it is, then you may not need to deviate from the GC route later in the weekend, and might be able to continue toward Ireland on that route.

In the short term, staying on the GC route is best, even with the headwinds and difficult seas. If this second low does end up following a track as was anticipated yesterday, then you need to be in a position to move farther north.

Winds today will back slowly toward NNW or perhaps NW, but speeds will increase a bit as you move closer to the circulation of the first low. You will also move into a region with larger seas, probably peaking in the 9-11 foot range later tonight and early tomorrow with wind speeds in the 20-25 knot range at that time. Conditions will then ease tomorrow afternoon and tomorrow night.

With the possibility of the second low being farther away from your route, you probably don’t have to push the SOA quite so much today, in fact being a bit slower will mean slightly less wind and sea for you later tonight.

I’ll send a more complete report later today, just wanted to get you this update.

Email with any questions.

P.S. In case you were wondering, then genesis of what I have been calling the second low was partly a fairly weak disturbance which yesterday was in northwestern Canada. As that disturbance moves farther east and is able to be better resolved by the models, the forecasts will become more reliable. All in all, though, what the numerical models can do as far as predicting weak disturbances in the flow to evolve into significant systems with reasonable accuracy is remarkable. But it is not 100 percent, for obvious reasons. So we will keep watching….

-- Editors note:  Bill & Ken had several back and forth e-mails yesterday (offline) sorting out the best tactical option to deal with this 2nd low that is forecast to travel across the previous southern route option middle of the week.  As forecasts for this system were still very early and the system is not yet developed there is a bit more uncertainty about just how strong it will form.  The several models I was looking at yesterday all agreed on timing and location, but strength of the low varied considerably.  Of the 4 models I have been able to look at today, 3  (GFS, PWC, & CMG) show a weaker system than yesterday's forecast with only the PWG model still showing it forming quite strongly.  In any case, all 4 show it tracking basically through the 39N/39W waypoint that Bill had been considering going through before yesterday, so this is why the boat has reverted to the original waypoints that Ken had suggested a week ago.  Basically they have turned towards Ireland which means some upwind sailing, but at least on a relatively direct route for now.
This screen capture shows the boats position as of this afternoon (green marker) with the weather forecast for Monday night.  By then the boat should be in the middle of the blue light air section with the 1st low well off to the east and the 2nd low due south of the boats expected position.

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