NOUS41 KWBC 011725

PNSWSH

 

Service Change Notice 12-27

National Weather Service Headquarters Washington DC

125 PM EDT Wed Aug 1 2012 

 

TO:       Subscribers:

          -Family of Services

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network

          -NOAAPort 

          Other NWS Partners, Users and Employees

 

FROM:      Mark Tew

          Branch Chief, Marine and Coastal Weather Services

 

SUBJECT:  New Experimental Wave Terminology Change to be used

          For Coastal Waters from Point Saint George to

          Point Arena, CA, Effective September 19, 2012

 

Effective Wednesday September 19, 2012, at 900 AM Pacific Daylight Time (PDT), 12 noon Eastern Daylight Time (EDT),
1600 Coordinated Universal Time (UTC)), the NWS Weather Forecast Office (WFO) in Eureka, CA, will change to a new terminology for describing the sea state in their Coastal Waters Forecast (CWF).

 

Areas affected include the coastal waters from Point Saint George to Point Arena, California. The purpose of the change is to evaluate the following wave terminology:

 

Sea state will be described by providing a total wave height along with additional detailed wave information when it is useful for the mariner. The amount of detailed wave information provided will depend on conditions. For example, when there is only a single wave, then that wave’s direction, height and period will be given. For example:

 

SEAS NW 6 TO 8 FT AT 10 SECONDS

 

When there are two distinct waves, then the total wave height will still be given, but the two waves that make up that sea state will also be described. For example:

 

SEAS 8 TO 10 FT...INCLUDING NW 7 FT AT 10 SECONDS AND SW 5 FT AT 14 SECONDS

 

When there are too many waves present to provide detailed information about each wave, the term CONFUSED will be used to let the mariner know that waves from many directions are present. Total wave height will be provided with the period from the biggest wave. For example:

 

CONFUSED SEAS 8 TO 10 FT AT 10 SECONDS

 

In some circumstances, only a total wave height will be provided without including direction and period. For example, when the sea state is very small or the forecast area is so large that there is great variability of the wave direction and period, only a total wave height may be given. For example:

 

SEAS 1 TO 2 FT

 

Finally, an example of a 5-day forecast from the Eureka, CA WFO may read:

 

TODAY...NW WIND 5 TO 15 KT. SEAS NW 6 TO 8 FT AT 10 SECONDS.

TONIGHT...N WIND 10 TO 20 KT. SEAS 7 TO 9 FT...INCLUDING N 3 FT AT 4 SECONDS AND NW 7 FT AT 11 SECONDS.

SAT...N WIND 10 TO 20 KT. SEAS 8 TO 10 FT...INCLUDING N 4 FT AT 4 SECONDS AND NW 7 FT AT 10 SECONDS.

SAT NIGHT...N WIND 20 TO 25 KT. SEAS 9 TO 11 FT...INCLUDING N 7 FT AT 6 SECONDS AND 6 FT AT 10 SECONDS.

SUN...N WIND 20 TO 30 KT WITH GUSTS TO 40 KT. SEAS N 9 TO 11 FT AT 9 SECONDS.

MON...N WIND 20 TO 30 KT WITH GUSTS TO 35 KT. SEAS N 9 TO 11 FT AT 9 SECONDS.

TUE...N WIND 15 TO 25 KT WITH GUSTS TO 30 KT. SEAS 7 TO 9 FT...INCLUDING N 6 FT AT 6 SECONDS AND W 5 FT AT 11 SECONDS.

 

The terms WIND WAVE and SWELL will no longer be used because the characteristics of the sea state will be communicated by using the more descriptive direction, height, and period of the individual wave system. The motivation for this change and a simple explanation of the significance of wave direction, height, and period is available at:

www.weather.gov/eureka/waves

 

The evaluation of the wave terminology will run at least through July 31, 2013.

 

If response is favorable, the NWS will consider expanding the test to other portions of the nation. These changes may be made permanent if the test results are favorable. If the test results are not favorable, the wave portion of the coastal waters forecast will revert to the previous method. Users are encouraged to provide feedback on this change to the marine forecast by using the brief survey and comment form available at:

 

http://www.nws.noaa.gov/survey/nws-survey.php?code=EENWT

 

Table 1 lists products issued by WFO Eureka affected by this change beginning September 19, 2012

 

Table 1: WFO EUREKA PRODUCTS

 

Product Name               AWIPS ID      WMO Heading

 

COASTAL WATERS FORECAST    CWFEKA        FZUS56 KEKA

NOTIFICATION

 

Table 2 contains lists of the current marine zones affected by the change in WFO Eureka Coastal Waters Forecast (CWF).

 

Table 2: Affected marine zones and corresponding UGCs for WFO Eureka

 

Current Marine Zone Name                       Current UGC

 

PT ST GEORGE TO CAPE MENDOCINO...OUT 10 NM            PZZ450

PT ST GEORGE TO CAPE MENDOCINO...10 TO 60 NM          PZZ470

CAPE MENDOCINO TO PT ARENA...OUT 10 NM                PZZ455

CAPE MENDOCINO TO PT ARENA...10 TO 60 NM              PZZ475       

 

Users do not need to make any changes to their systems in order to continue to receive the Coastal Waters Forecast (CWF) product from WFO Eureka.

 

For questions or comments about this change, contact:

 

Troy Nicolini

Warning Coordination Meteorologist

NOAA National Weather Service

Eureka, CA 95501-6000

707-443-6484 x 223

troy.nicolini@noaa.gov

 

NWS Public Information Statements are online at:

 

http://www.weather.gov/os/notif.htm

 

$$