Feather Worecasting

[Peter Taylor]

Am I right in remembering ....that one of the UK Olympic sailing team back then pioneered having their own forecasting boffins with them?

The olympic sailing team certainly do get their own forecasters, I don't know when it started. My instrumentation engineer went to the Seoul Olympics (1988) as a reserve for the Int.14's event and we did some modelling for that, I can't remember whether it was airflow or the currents in the bay.  For the recent UK Olympics they asked if we could model airflow in Weymouth Bay taking into account the effects of Portland Bill - my research team ran computer models of airflow over ships to correct our wind data (it's call Computational Fluid Dynamics, CFD).  Unfortunately by 2012 anything we did had to be paid for and the RYA didn't have the sort of money we needed to charge for the work.  I suggested asking someone with local knowledge was a good alternative!  All the support ribs for the UK Olympic team carried anemometers, and during the trials I think they also put some instrumented buoys out.

I'm attaching an example of CFD calculations showing the percentage change in airflow over a research ship - all that is shown is one cross section along the ship's centre line for bow on winds. The calculations are actually done for a whole box containing the ship and for different wind angles.  The photo shows how we measured the winds on that ship using a bow mast - the research anemometers are at either end of the cross trees and measure 3 components of wind velocity about 80 times per second!

[Michael Rogers]

Yes, well, I can vouch for the huge wind shadow (vis a vis a small dinghy) of the Sandbanks chain ferry when trying to sail into Poole Harbour against the ebb and a north-westerly breeze. Without the ferry I would have made it. Still, it was good fun trying, and after frequent visits I got quite friendly with the circle of cormorants sitting on the nearest channel buoy.

David, thanks for the windyty suggestion. I've got it bookmarked.

Michael

[Graham W]

Here's Joe Heenan's idea of what the new BBC UK weather forecasts may look like