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Flying Pig Float Plan
On Jul 28, 8:34*am, GeoffSchultz
wrote: ... I find exactly the opposite to be true. *The NOAA forecasts are much more reliable off shore than they are on-shore where land effects can significantly modify the wind patterns. *I believe that they even state that the forecasts are for 12+ miles off-shore. ... I don't know where you sail. However, my guess is you are not using the correct weather product. In most places in the USA NOAA provides marine forecasts in zones. The zones tend to be along the lines of near-shore, coastal and offshore with near-shore zones being the smallest and having the highest detail the offshore the largest and least detailed. The near shore and coastal products do take land effects into account. For instance, there are nine zones for which NOAA produces marine products in the bay and sea areas around San Francisco. That's pretty typical. The reason they go to all that trouble is that the wx is often quite different in each zone. So, yes it is likely they do provide a product that is only valid 12+ miles off shore in your area. But, if they do then they almost certainly also have one for the near shore waters and the reason they have another zone is that they expect the wx to be different nearer shore and the near shore. It shouldn't come as a surprise that the 12+ mile out forecast does a poor job of predicting things closer in. If you want to geek out on this then you will want to look into the meso scale modeling. You can get NAM and COAMPS grib data from NOAA for the coastal waters of North America. If you check it out I think you'll see that the models do take local geographical features into account. Near shore your local wx dude has these high resolution models, radar, reporting stations, and so on giving him the best information to build his forecast from and a small area to prognosticate over. As the forecast area moves offshore and gets larger he has less detailed information and has to average the forecast over a larger area and, IME, the results are, as you would expect less accurate. YMMV. -- Tom. |
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