NOUS41 KWBC 051845



Technical Implementation Notice 11-38

National Weather Service Headquarters Washington DC

245 PM EDT Fri Aug 5 2011


To:         Subscribers

            -Family of Services

            -NOAA Weather Wire Service

            -Emergency Managers Weather Information Network


            -Other NWS Partners and Employees


From:       Richard J. Vogt

            Director, WSR-88D Radar Operations Center


Subject:    NWS Field Test Using New WSR-88D in Grays Harbor

            County, WA


Reference:  SCN11-23 Sent June 17 2011, New WSR-88D Installation

            Information effective no later than September 30,



A new Weather Surveillance Radar-1988, Doppler (WSR-88D) in Grays Harbor County, WA, is expected to be operational by September 30, 2011.  The NWS is planning a 1-year field test of an additional scanning angle less than 0.5 degree elevation (initially 0.176 degree) on the new radar to determine the operational benefit(s) of having a lower scan angle. The test is scheduled to begin November 1, 2011.


To reduce impacts on users, Level III products will not include data from the lower scanning angle.  Thus, the product formats and contents will not change during the field test.  Users will notice volume coverage pattern (VCP) durations increase by
30 to 150 seconds when the experimental lower scanning angle
is in use.


To support the real-time and post-analysis of the impacts of the lower scan angle data, the Level II data stream will include the data from the experimental lower scan angle when in use.  The Seattle Weather Forecast Office will be able to turn the lower elevation scan on and off. Details of Level II data changes when the additional test scan angle is being used are as follows:


1. Experimental VCP numbers will increase by two, i.e., VCP11 will be VCP13

2. Lower scan data will be the first radial data in a Level II file

3. The lower scan will be a "Split Cut"


Additional information is available at:


If you have questions or comments, please contact:


     Tim Crum

     WSR-88D Radar Operations Center


National Technical Implementation Notices are online at: