Monday, December 21, 2020
I am not sure if I actually heard the four W’s from someone or just made it up. I vaguely feel that I was told to consider the four W’s from a surf instructor in Mexico for water safety. But it may be a conflation of the five W’s: who, what, where, when, and why. In any case, the (my) four W’s are weather, wind, water, and waves. There is some obvious overlap but the following is a bit of detail regarding each variable.
When thinking about the weather you want to cover the basics of what the forecast is. What is the temperature, will there be any precipitation, what is the visibility like, etc. But keep in mind that a forecast is just that, a forecast. The weather prediction is subject to error as well as change and this should be considered in your planning. Take into consideration how long you will be out for and what the likelihood of change would be. Your weather forecast is meant to allow you to plan your trip for whether or not (pun intended) you should go and what you need to have an enjoyable paddle. For example, do you need sunscreen, warm clothing, hat versus toque, or board shorts versus a wetsuit? The last point here is to dress for the water and not the air temperature. For fall or winter paddling having warm, dry clothes is great, but if you unexpectedly end up in the water that can all change quickly. The adage hope for the best but plan for the worst is apt.
The wind is a specific extension of your general weather forecast. When you are out on the water on your stand up paddleboard you are essentially a sail. Wind can either be your friend, if you are heading downwind or your foe if you are heading upwind or crosswind. Be sure to know the direction as well as the speed. It is also worth considering the interaction of the wind with the water/waves. But before we get into that here is a quick synopsis on the wind (because it has taken me some time to get this straight in my mind and I think I have it figured out now).
Wind results from changes in pressure gradients in the atmosphere and these are highly related to temperature. Remember your high school physics and chemistry classes. Molecules move from areas of high concentration or pressure to areas of low concentration or pressure. The wind is what we experience as a result of air molecules moving from areas of high pressure to low pressure. This is ultimately driven by temperature. Check out this brief video overview below from the NOAA SciJinks. Or if you want to nerd out check out the free online course content from UBC’s EOAS on Weather for Sailing, Flying and Snow Sports (I am slowly making my way through this content).
When talking about wind direction it is named by the cardinal (or compass) direction that it comes from or where it originates. For example, a westerly wind is coming from the west (and blowing towards the east). Wikipedia’s page on wind direction does a good job with the basics. Pretty straightforward so far, right. And here is where I get confused.
Logically, to me, it would follow that the same rule or heuristic would hold for naming onshore and offshore winds. Wrong! When describing coastal winds the naming convention reverses from that of wind direction. Now, the wind is described by where it is going (not by where it is coming from). So, an onshore wind blows from the sea towards the land (or onto the shore). Whereas an offshore wind blows from the land towards the sea. For myself, I think of adding words in between the prefix and “shore” to give more clarity. An onshore wind becomes a wind that blows on to the shore. And an offshore wind becomes a wind that blows off of the shore. But maybe it is just easier to know that it is the opposite of wind direction, assuming you have that down already. Paddle Monster has a great post on deciphering wind.
Now going back to the discussion on interactions of the W’s. When surfing a shore break it is ideal to have an offshore wind (i.e. blowing from the land out to sea) with waves coming crashing into the shoreline. The reason for this is that the wind will hold the waves up a little bit by blowing them back out to sea and preventing them from curling and crashing too soon. Not to mention it probably helps with giving a cool photo finish when you have the mist off the crest of the waves being carried off out to sea.
You can add one more interaction by including weather in the scenario above. If the forecast calls for warm weather you can predict wind direction. This is because the surface temperature overland is more labile than overwater. At night the land surface temperature will drop more than the water surface temperature and as a result, the air over the water will be warmer and thus at lower pressure. Under these conditions, the cooler higher-pressure air inland will rush out to the warmer sea making for more ideal wave conditions. However, in fair weather (e.g. summer) during the day the sun will heat the land surface temperature more so than the water surface temperature. As a result the process above with reverse. The warmer air over land will reduce the air pressure resulting in a gradient forcing the offshore air inland (offshore wind). Knowing the weather forecast would thus allow you to predict the wind direction and the surf conditions.
For planning consider using the wind in your favour for one-way trips or at the end of trips for round-trips so that you have a tailwind when fatigued.
For water, there are a host of things to consider. It is important to consider temperature, tides, currents, and other hazards (for example depth and underwater hazards like pilings or dolphins). At the same time depending on the body of water you need to consider things like other vessels (sailboats, powerboats, ferries, seaplanes, etc.). And what, if anything, these vessels could do the water. For example, a tugboat passing a tugboat in the Fraser River can produce a tonne of wake which depending on your direction and the boast could be great or not so welcomed. I also have taken an unexpected dip (or two) in the Fraser as a result of a partially submerged jetty and an eddy from a ferry/tugboat. Fortunately, these have all be learning points, but some better planning on my behalf could have avoided these potentially dangerous situations.
As with wind, try to plan to have currents or tides to help you at the end of your journey whenever possible. And when that is not possible be sure to consider that for your energy, speed, and safety.
Again waves can be a help or hindrance. There is no better way to build your confidence and strength than paddling into some tough wavey conditions. But at the same time, you must ensure that you set yourself up for success. Your waves are going to result from both the tidal flows as well as wind. If there is a long fetch (i.e. distance for the wind to build up waves) the waves will be bigger with less wind. And like wind, waves from in front or from the side can be a challenge. In my experience cross waves have been more challenging to deal with than crosswinds, but that is also a by-product of planning to not have huge crosswinds to paddle through. So far, I will take big head waves over big headwind anytime.
Check out my post on tools and resources for weather and tide apps.