Service Change Notice 17-134

National Weather Service Headquarters, Silver Spring, MD

310 PM EST Thu Dec 14 2017


To:         Subscribers

            -NOAA Weather Wire Service

            -Emergency Managers Weather Information Network


            Other NWS Partners and Employees


From:       Terrance J. Clark

            Director, WSR-88D Radar Operations Center


Subject:    Supplemental Low Elevation Angle Implemented

            due to Urgent Mission Needs at KMUX WSR-88D San

            Francisco, CA on or about December 26, 2017


The Radar Operations Center, in conjunction with NWS Western

Region Headquarters and the Weather Forecast Office San

Francisco Bay Area, will implement a supplemental low elevation

angle of +0.2 degrees on or about December 26, 2017. This angle

is in addition to the standard +0.5 degree angle and will be

included in all Volume Coverage Patterns (VCPs).


Due to historic California wildfires and burn scars, there is an

urgent need to lower the elevation angle at KMUX for improved

detection of precipitation and associated hazards.


KMUX was previously planned for a low elevation angle test in

spring 2018. An environmental assessment was completed for the

site within the last year and a Finding of No Significant Impact

(FONSI) was determined. The FONSI for KMUX is available here:


The low elevation angle field test will continue as planned for

KMUX in spring 2018, with more information provided at a later

date. Due to the urgent circumstances associated with the

California wildfires, the +0.2 angle will be implemented on or

after December 26, 2017 and remain in effect until the start of

the field test in spring 2018.


Changes for external users will be similar to those required 

for the low elevation angle of +0.2 degrees at KLGX 

Langley Hill, WA.


For questions or comments, please contact:

      Jessica Schultz

      NWS Radar Focal Point

      Radar Operations Center


National Service Change Notices are online at: