The Importance of Wind Speed and Direction
The degree of roughness of the water in the ARC stretch of river is highly dependent on both the speed and the direction of the wind.
In the section of river that stretches from boathouse up the river to the bend below the PSNH Bow power plant, the water will be roughest for any given wind speed when the wind is from the S, SSW or N. In the sections of river beyond the bend, the water will be roughest when the wind is from the SE or NW. From these directions, the wind is blowing up or down the length of the river respectively. The wind gathers strength and the waves have time and distance to build. The water is calmest on the whole river when the wind is from the E, ENE, W or WSW and therefore blowing across the river. The map below with the inset compass rose will show you how the ARC stretch of river lays out relative to these directions .
The boathouse/launch area will be relatively calm under almost all conditions except when the wind is from the N or NNW. The relative calm at the launch can disguise the fact that the water might be uncomfortably rough elsewhere on the river. In particular, if the wind is strong from the S or SSW the launch area will be relatively calm but the water will quickly become much rougher as you progress up the river.
The weather service puts out most forecasts in 16 point compass format but also provides some weather data in degrees. The map linked below shows the ARC stretch of river with a 16 point, 360 degree marked compass rose superimposed (with apologies to the artist) on the standard ARC river map. This map will allow you to readily determine how any forecast wind direction or weather data relates to the river. Remember that the wind will be coming FROM the direction given in the forecast. The longer part of the diamond/arrows in the compass rose (i.e. the parts that point toward the center of the circle) point with the wind (the direction in which the wind is represented to be blowing). The stubby arrows pointing outward on the compass rose point to the degrees that are associated with that particular point.
The Beaufort Wind ScaleSimple Table | Cartoon Illustration | The Whole Story
Thinking about wind in terms of this standard scale will help you categorize different wind conditions and give you a common reference point for talking with other rowers (or any nautical types) about your experience on the water. This scale was originally created for the sea but has been adapted for inland use. Many rowers find that a Force 3 or (Gentle Breeze / 8-12 mph) as defined on the Beaufort Scale is the boundary between pleasant rowing and not going out on the water (or heading for home) – at least when rowing a racing shell, particularly a single.