This is part of a computer forecast graphic of sea level pressure in millibars and wind in knots near the surface of the ground for June 6th, 1999 at 1 PM EST. See how the shaft of the wind ( The little green thing ) has a small dot at the end. The wind blows along the shaft toward the dot. And see how easy it is to check how the wind is gonna be offshore, onshore or cross-shore? This is a Good Thing!
The wind barbs which come out at right angles to the shaft show the wind speed. Each full barb is 10 knots, each half barb is 5 knots, each flag is 50 knots. 10 knots equals about 11.5 mph. For instance, the wind at the Cape in this graphic is about ten knots out of the south-southwest : not quite offshore, in fact coming towards cross-shore. It's about ten knots, which is enough to keep life at the beach comfortable and add a little chop but not screw things up completely.
Now, look around the graphic a bit. Uh huh. Further offshore the wind is stronger, right? One and a half flags; fifteen knots, around 20 MPH...enough to make life at the beach unpleasant, blowing sand, big chop and so on. And down to the south, off Long Island, you see the shafts with a direction, but half a flag or no flag at all. Hardly any wind, in other words.
Also- see the yellow lines and the numbers? Notice how the numbers get lower as they go to the North and West. Those are air pressure: there is a low pressure area more or less to the Northwest of Cape Cod...which gives you the idea that a low is coming over.
Basicly, you want to bear in mind three things about winds, at least as it applies to surfing:
- Onshore winds produce storm slop: Bad.
- Cross-shore winds make chop and screw up the waves: Bad.
- Offshore winds are good. Period.
For current New England wind maps, go here
New
Bouys and how to use them to identify and track swells
For a few ways to use buoys to track swells and figure out where they are coming from, click here.
