Weather Forecasting Basics

What is wind?
Air is set in motion when Mother Nature tries stabilizing regions of excess with regions of deficit. This results in air moving from high to low pressure systems in attempts to equalize everything. Basically, when pressures change, winds blow. For kiteboarding, you should measure wind using three characteristics: Speed, Direction and the often overlooked Change Factor. Ising the Beaufort Wind Scale can help you zone in on these.

Waters

When winds “blow,” they also affect water topography

• White caps indicate both speed & direction. White caps start around 12knots. The larger and more frequent they are, the stronger the wind. You can also tell the change factor by watching how frequent they shift direction and increase/decrease in number.


• Flatter glass like water indicates little air movement, assuming there are no obstructions under water. If you’re riding and notice glassy spots forming, either the water is getting shallow with an outgoing tide or winds are decreasing and may stop completely.


• Darker patches often look like a cloud shadow that’s moving. Typically this indicates a strong gust that is at least more than 5kts greater than current wind speed.


• Consistent water textures indicate stable winds.


• Often, you can see the wind “line.” In some areas, winds may be light near shore, but stronger out at sea. On the beach you can actually see the line where white caps will start. A moving line shows stronger winds approaching. Wind lines can move fast (i.e., squalls), if you see one, take extreme caution.


• A wind blowing against a tide or strong current causes a greater disturbance and sea-wave height than you would normally expect (i.e., an onshore wind and outgoing tide).


• A wind blowing in the same direction as a tide or strong current causes a smaller sea-wave height and sea disturbance than normal. (such as an offshore wind and an outgoing tide).


• There is a time lag between the wind increasing/decreasing and the sea-wave height rising/falling.


• Sea-waves (also known as wind-waves) are generated by the wind blowing over a given time in the local area. After being generated by conditions elsewhere in a particular basin of water, Swell-Waves oftentimes traveled 100s or 1000s of miles before reaching a local area. They tend move in and out over a noticeable time period.

The Law of Turbulence
When wind flows over an object, it becomes turbulent for 3x the height of that object upwind and side wind, and 7x the object’s height downwind.

If the world was flat and smooth, there would be little wind variation from place to place. But by adding topography (hills, valleys, trees, buildings, etc), a complex and highly variable wind regime exists. Known as Surface Friction, it affects all three wind traits. Rough surfaces, like areas with trees and buildings, will produce more friction and turbulence than smooth surfaces such as lakes or open cropland.

The greater friction means the wind speed near the ground is reduced. Obstructions can drastically reduce wind quality by adding evil turbulence. Friction can only affect wind after air is in motion. While buildings, hills, valleys, trees and mountains typically create drag, each geographical feature influences wind flow in certain ways. We say typically, because in certain conditions, high terrain and valleys can actually increase wind speeds.

Weather Laws & Guidelines
Because weather affects everything around, nature makes it possible in foretelling how “epic” your kiting session might be. The following is the short version of our “wind laws” cheat sheet. While they are not hard core rules that govern weather, using them will help you predict future wind behavior and have more great sessions.

Time tells all . . .

• A Nighttime OR sunrise wind that’s steady or increasing typically means weather is soon going to change drastically.
• Light night winds with a brightly lit moon often mean the next day will be clear and calm with a possible Sea Breeze.
• Wind speeds typically increase during daylight hours and decrease at sunset.

Birds have an amazing relationship with wind. And, they have lots to say:

• Fish crows often do their loudest chattering to announce approaching windy weather.
• Shorebirds will always rest on land facing into the wind.
• Swallows go toward trees with the approach of windy weather.
• Pigeons race after one another with a fierce beating of their wings to indicate the approach of increasing winds.
• Sea gulls gather on land as a sign of possible increasing winds.

I can honestly say our best kiting has always happened on clear sunny days. Know as both wind throwers and killers, clouds can tell you many things:

• Clouds Kill Wind. You’ll typically find wind speeds decreasing as clouds move in, killing the heat. If you’re in a thermal driven area and see a cloud line approaching, your winds will likely weaken significantly.
• Convection is Dangerous. Also known as thunderstorms, convection often produces strong, shifting winds as air rises and sinks quickly. You should always avoid riding if you notice towering cumulonimbus cloud systems approaching. Winds may suddenly change direction and/or speed without notice.
• Well defined cumuliform clouds with hard edges often indicate winds will increase.
• The softer the look of clouds, the less wind there will be as weather stablizes.
• Rolled or ragged clouds tell the coming of strong wind.
• Sudden, short duration rain can be accompanied by strong winds.
• Rain with an east wind usually lasts for a while.
• Rain with a west or northwest wind is usually an indication that the rain is coming to an end.
• Sunny days typically produce greater air mixing than cloudy days. This produces more stable wind.