2100 Second Street, S.W.
United States Coast Guard
Washington, DC 20593-0001
3 DEC 1994
COMMANDANT INSTRUCTION 3140.2D
Subj: Marine Weather Observation and Reporting
PURPOSE. This Instruction sets forth the policy for observing and reporting weather information
from Coast Guard cutters, and provides information for obtaining weather instruments and
DIRECTIVES AFFECTED. Commandant Instruction 3140.2C is cancelled.
PROGRAM OBJECTIVES. This program is established to assist the National Weather Service
(NWS) and the Naval Oceanography Command in collecting marine weather data to support public
and national defense needs.
DISCUSSION. The National Weather Service has statutory responsibility for providing weather
forecasts for public use. Under the authority of 14 USC 147, the Coast Guard cooperates with
NWS by reporting marine weather observations. These observations are often the only marine
information available to weather forecasting facilities and, as such, are critical to accurate weather
analysis and forecasting. Real time reports of observed marine weather conditions are used several
times daily as part of the marine and land forecasting scheme. Completed logs are used for
preparation of marine climatology atlases and various marine research activities. The U.S. Navy
uses marine weather data to provide environmental forecasts and services in support of fleet
operations. As part of those services, the Navy provides weather forecasts (WEAX) and Optimum
Track Ship Routing (OTSR) to Coast Guard cutters upon request.
Units Affected. For purposes of this Instruction, cutters responsible for making marine
weather observations are designated as Category One or Category Two as follows: