Seastate description beaufort wind scale wave height feet 0 sea like a mirror wind calm sea state. Pdf toward a revised beaufort equivalent scale researchgate. Kayaking inspired gifts sales help support this site. Howtoons poster showing effects on land sea effects at each step. Ripples with the appearance of scales are formed, but without foam crests. V the corresponding wind speed in miles per hour 30 feet above the surface of the sea. Ideally one should quote both, so in this case the sea conditions would be described as sea. The significant wave height h the mean height of the one third highest waves.
The beaufort scale of winds royal meteorological society. Sea state conditions measured by the beaufort scale from bowditch. Originally based on the effect of the wind on a fullrigged manofwar, in 1838 it became mandatory for log entries in all. The beaufort scale is an empirical measure for the intensity of the wind based mainly on sea state or wave conditions. Beaufort sea states the beaufort sea state code is a simple scale that can be used to give an approximate but concise description of sea conditions. Also, see estimating wind while on land printable version. Sea surface like a mirror, but not necessarily flat. The beaufort scale is an empirical measure for the intensity of the wind based mainly on seastate or wave conditions. Direction of wind shown by smoke drift, but not wind vanes. There is a good discussion about the difference between waves and swell on the new zealand met service blog. The beaufort sea state code is a simple scale that can be used to give an approximate but concise description of sea conditions.
Even when a correct identification of the sea state is made. Having said that, in many cases the swell part is not quoted. In engineering applications, sea states are often characterized by the following two parameters. Historical wind speed equivalents of the beaufort scale. Estimating wind speed and sea state with visual clues beaufort number wind description wind speed wave height visual clues 0 calm 0 knots 0 feet sea is like a mirror. When compared to the old wmo code 1100 beaufort scale estimates, our. Created by sir francis beaufort in 1805, an irish born british admiral and hydrographer.
National meteorological library and archive fact sheet on the history of the beaufort scale, including various scales and photographic depictions of the sea state. Estimating wind speed and sea state with visual clues. Seastate description beaufort wind scale wave height. National meteorological library and archive fact sheet on the history of the beaufort scale. The beaufort scale was used to estimate the weather via visual observation to standardized each individuals opinion about the state of the wind at sea, where originally one. It is currently still in use for this same purpose as well as to tie together various components of weather wind strength, sea state, observable effects into a unified picture. Small wavelets, still short but more pronounced, crests have glassy appearance and do not break. During shorewatches, wdcs cetacean researchers use the beaufort sea state code as part of their shore watch protocol. Bridge officers on ships can readily estimate the wind force using the descrip tions of sea state defined by the world.
Ideally one should use both scales to fully describe the conditions. Specifications and equivalent speeds for use at sea. Beaufort scale force 11 seas with waves 1116 metres high and wind 5663 knots. Marine beaufort scale the beaufort scale was originally developed in 1805 by sir francis beaufort as a system for estimating wind strengths without the use of instruments. Wind stings face in temperatures below 35 deg f 2c. Beaufort scale, in full beaufort wind force scale, scale devised in 1805 by commander later admiral and knight commander of the bath francis beaufort of the british navy for observing and classifying wind force at sea. Appendix viii beaufort wind and douglas sea scales. The douglas scale has two parts sea state ie waves and swell.