Beaufort Wind Scale

Beaufort
Force

Windspeed
Knots

Description

Wave Height in feet

Sea State

Picture

0

0

0

1

1 - 3

0 - 1/4

2

4 - 6

1/2 - 1

3

7 - 10

1 1/2 - 3

4

11 - 16

3 1/2 - 5

5

17 - 21

5 - 8

6

22 - 27

8 - 13

7

28 - 33

13 -18

8

34 - 40

18 - 28

9

41 - 47

23 - 32

10

48 - 55

29 - 41

11

56 - 63

39 - 46

12

64+

47 - 52

The Coastal Warning Display program was de-emphasized in favor of frequently updated telephone recordings and NOAA Weather Radio . The latter covers the coastal areas of continental United States, Alaska, Hawaii, and the Mariana Islands with continuous weather broadcasts. The major shortcomings of the Coastal Warning Display program were that the displays reached only the small portion of the marine public within sight of them; it cannot convey specific information on movement, intensity, and duration; and the time required to notify the sites by individual telephone calls takes the forecaster away from critical tasks associated with the weather. Further, when users perceive them to be a full substitute for NOAA Weather Radio, other radio broadcasts, and the telephone recordings, they are actually being a disservice.

Coastal Warning Display Signals

Daytime Signals

Night Time Lighted Signals

Explanation of Warnings

SMALL CRAFT ADVISORY: To alert mariners to sustained (more than two hours) weather or sea conditions, either present or forecast, that might be hazardous to small boats. If a mariner notices a Small Craft Advisory pennant displayed he should determine immediately the reason by tuning his radio to the latest marine broadcast. Decision as to the degree of hazard will be left up to the boatman, based on his experience and size and type of boat. There is no legal definition of "small craft". The Small Craft Advisory is an advisory in Coastal Waters and Nearshore forecasts for sustained winds, frequent gusts, or sea/wave conditions, exceeding defined thresholds specific to geographic areas. A Small Craft Advisory may also be issued when sea or lake ice exists that could be hazardous to small boats.

Eastern (ME..SC, Lake Erie, Lake Ontario) - Sustained winds ranging between 25 and 33 knots (except 20 to 25 knots, lower threshold area dependent, to 33 knots for harbors, bays, etc.) and/or seas/waves 5 to 7 feet and greater, area dependent.

Central (WI..OH) - Sustained winds or frequent gusts between 22 and 33 knots inclusive, and/or seas/waves greater than 4 feet.

Southern (GA..TX and Caribbean) - Sustained winds of 20 to 33 knots, and/or forecast seas 7 feet or greater that are/is expected for more than 2 hours.

Western (WA..CA) - Sustained winds of 21 to 33 knots. A Small Craft Advisory for Hazardous Seas is issued for seas 10 feet or greater.

Alaska (AK) - Sustained winds or frequent gusts of 23 to 33 knots. A small craft advisory for rough seas may be issued for sea/wave conditions deemed locally significant, based on customer needs, and should be no lower than 8 feet.

Pacific (HI, Guam, etc) - Sustained winds : northwest through east/southeast winds of 25 to33 knots for the coastal waters (30 to 33 knots for the channels between the islands); southeast through west winds of 20 to 33 knots for both coastal waters and channel winds. Swells : open ocean swells 10 feet and greater; swells 6 feet and greater with short periods (6 to 8 seconds); south swell 4 feet and greater with long periods (13 seconds and greater); north and northeast swells 5 feet and greater with long periods.

“Frequent gusts”are typically long duration conditions (greater than 2 hours).

For a list of NWS Weather Offices by Region, refer to the following website: http://www.nws.noaa.gov/organization.php

GALE WARNING: To indicate winds within the range 34 to 47 knots are forecast for the area.

STORM WARNING: To indicate winds 48 knots and above, no matter how high the speed, are forecast for the area. However, if the winds are associated with a tropical cyclone (hurricane), the STORM WARNING indicates that winds within the range 48-63 knots are forecast.

HURRICANE WARNING: Issued only in connection with a tropical cyclone (hurricane) to indicate that winds 64 knots and above are forecast for the area.

NOTE: A "HURRICANE WATCH" is an announcement issued by the National Weather Service via press and television broadcasts whenever a tropical storm or hurricane becomes a threat to a coastal area. The "Hurricane Watch" announcement is not a warning, rather it indicates that the hurricane is near enough that everyone in the area covered by the "Watch" should listen to their radios for subsequent advisories and be ready to take precautionary action in case hurricane warnings are issued.

NOTE: A SPECIAL MARINE WARNING is issued whenever a severe local storm or strong wind of brief duration is imminent and is not covered by existing warnings or advisories. No visual displays will be used in connection with the Special Marine Warning Bulletin; boaters will be able to receive these special warnings by keeping tuned to a NOAA Weather Radio station or to Coast Guard and commercial radio stations that transmit marine weather information.

Much of this information was gathered from the National Weather Service website:
http://www.weather.gov/

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