JP 3-50 National Search and Rescue Manual Vol I - US Navy

445 Weather
A. Weather may limit SAR missions. Not only are search targets
more difficult to detect, but SRUs operate less efficiently in
turbulence or rough seas. Knowledge of weather conditions and prudent
judgment will increase the likelihood of a mission success and SRU
safety.
B. If existing weather will not allow a search without unduly
endangering additional lives, the search should be delayed. If weather
is good but forecast to deteriorate, rapid action is necessary, possibly
in lieu of detailed planning.
C. Wind, visibility, and cloud cover influence search sweep width.
Accurate search planning is influenced by accurate weather information.
D. SRU safety should be of concern to the SMC. Low ceilings and
restricted visibility are particularly hazardous to aircraft. If the
search is to be conducted where few navigation aids and poor visibility
exist, the SMC may suspend search operations or limit the number of
SRUs. OSCs may suspend the search to ensure SRU safety.
E. For overdue craft, the weather at the departure point and the
destination, and along the likely track, should be evaluated for the
effect it may have had on the craft. Other factors are:
1. The en route and forecast weather information that was
available to the crew of the missing craft.
2. Any marked changes in wind or sea currents that might have
resulted in navigation errors, or any areas of marked pressure
changes that might have caused aircraft altimeter errors.
3. Any areas of low ceiling, poor visibility, precipitation,
thunderstorms, frontal activity, turbulence, or icing that the
craft may have attempted to circumnavigate, or that may have
exceeded craft or operator capabilities.
4. The weather in the area where the missing craft is presumed to
be located.
446 Other Considerations
A. Mission Risks. SAR personnel are responsible for taking
whatever action they can to save life at any time and place where
facilities are available and can be effectively used. All reasonable
action should be taken to locate distressed persons, determine their
status, and effect their rescue. However, SAR response should be
commensurate with the perceived possibility of saving life or property.
The risks inherent in any SAR response must be carefully weighed against
the mission's chances for success, that is, the saving of life or, to
lesser extent, property. Conducting prolonged SAR after the probability
of survival has approached zero is normally not warranted.