North Pacific Pilot Charts

hurricane

Introduction

I got tired of waiting for the Defense Mapping Agency to publish electronic versions of the Atlas of Pilot Charts North Pacific Ocean, so I scanned part of the eastern Pacific Ocean, covering the region from Anchorage to Hawaii to Baja, including the Pacific coast of Canada and the United States.

Click on the month links to the right to view winds for each month.

This is only a fragment of the entire document, and should not be used for navigation. Furthermore, I bear no responsibility for the accuracy of these charts.

All data is extracted from Defense Mapping Agency publication NVPUB108, Third Edition 1994 (No Copyright claimed under Title 17 U.S.C.).


Beaufort number Wind speed Mean wind speed (kt / km/h / mph) Description Wave height Sea conditions Land conditions
kt km/h mph m/s m ft
0 0 0 0 0-0.2 0 / 0 / 0 Calm 0 0 Flat. Calm. Smoke rises vertically.
1 1-3 1-6 1-3 0.3-1.5 2 / 4 / 2 Light air 0.1 0.33 Ripples without crests. Wind motion visible in smoke.
2 4-6 7-11 4-7 1.6-3.3 5 / 9 / 6 Light breeze 0.2 0.66 Small wavelets. Crests of glassy appearance, not breaking Wind felt on exposed skin. Leaves rustle.
3 7-10 12-19 8-12 3.4-5.4 9 / 17 / 11 Gentle breeze 0.6 2 Large wavelets. Crests begin to break; scattered whitecaps Leaves and smaller twigs in constant motion.
4 11-16 20-29 13-18 5.5-7.9 13 / 24 / 15 Moderate breeze 1 3.3 Small waves. Dust and loose paper raised. Small branches begin to move.
5 17-21 30-39 19-24 8.0-10.7 19 / 35 / 22 Fresh breeze 2 6.6 Moderate (1.2 m) longer waves. Some foam and spray. Smaller trees sway.
6 22-27 40-50 25-31 10.8-13.8 24 / 44 / 27 Strong breeze 3 9.9 Large waves with foam crests and some spray. Large branches in motion. Whistling heard in overhead wires. Umbrella use becomes difficult.
7 28-33 51-62 32-38 13.9-17.1 30 / 56 / 35 Near gale 4 13.1 Sea heaps up and foam begins to streak. Whole trees in motion. Effort needed to walk against the wind.
8 34-40 63-75 39-46 17.2-20.7 37 / 68 / 42 Gale 5.5 18 Moderately high waves with breaking crests forming spindrift. Streaks of foam. Twigs broken from trees. Cars veer on road.
9 41-47 76-87 47-54 20.8-24.4 44 / 81 / 50 Strong gale 7 23 High waves (2.75 m) with dense foam. Wave crests start to roll over. Considerable spray. Light structure damage.
10 48-55 88-102 55-63 24.5-28.4 52 / 96 / 60 Storm 9 29.5 Very high waves. The sea surface is white and there is considerable tumbling. Visibility is reduced. Trees uprooted. Considerable structural damage.
11 56-63 103-117 64-72 28.5-32.6 60 / 111 / 69 Violent storm 11.5 37.7 Exceptionally high waves. Widespread structural damage.
12 >63 >117 >72 >32.7 N/A Hurricane 14+ 46+ Huge waves. Air filled with foam and spray. Sea completely white with driving spray. Visibility very greatly reduced. Considerable and widespread damage to structures.