|Supplementary Weather Product Description
The definitions for weather product status can be found in FSIMS
Order 8900.1, paragraph 3-2073. These definitions technically refer
to air carriers but Flight Standards has consistently used this
definition for General Aviation as well. Similar definitions that
may cover GA are contained in AIM
For reference the relevant FSIMS paragraph is provided below:
"3-2073. CLASSIFICATION OF AVIATION WEATHER PRODUCTS.
A. The development of new aviation weather products is an
evolutionary process with distinct stages of product maturity. The
growing demand for new weather products and the corresponding
increase in research and development to meet that demand, along with
relatively unfettered access to weather information via the public
Internet, created confusion within the aviation community regarding
the relationship between regulatory requirements and new weather
products. Consequently, the FAA finds it necessary to differentiate
between those weather products that may be used to comply with
regulatory requirements and those that may only be used to improve
situational awareness. To clarify the proper use of aviation weather
products to meet the requirements of the regulations, the FAA
developed the following definitions:
1. Primary Weather Product. An aviation weather product that
meets all the regulatory requirements and safety needs, for use in
making flight-related aviation weather decisions.
2. Supplementary Weather Product. A aviation weather product that
may be used for enhanced situational awareness. If used, a
supplementary weather product must only be used in conjunction with
one or more primary weather products. In addition, the FAA may
further restrict the use of supplementary weather products through
limitations described in the product label.
NOTE: An aviation weather product produced by the Federal
Government is a primary product unless designated as a supplementary
product by the FAA.
B. In developing the definitions of primary and supplementary
weather products, it is not the intent of the FAA to change or
increase the regulatory burden upon certificate holders. Rather, the
definitions are meant to eliminate confusion by differentiating
between products that may be used to meet regulatory requirements
and other products that may only be used to improve situational
C. All flight-related, aviation weather decisions must be based
on primary weather products. Supplementary weather products augment
the primary products by providing additional weather information,
but may not be used as stand-alone products to meet aviation weather
regulatory requirements or without the relevant primary products.
When discrepancies exist between primary and supplementary products
pertaining to the same weather phenomena, users must base
flight-related decisions on the primary weather product.
Furthermore, multiple primary products may be necessary to meet all
aviation weather regulatory requirements.
D. As previously noted, the FAA may choose to restrict certain
weather products to specific types of usage or classes of user. Any
limitations imposed by the FAA on the use of a product will appear
in the product label."