Here's a short story:

The World Meteorological Organization (WMO) is an intergovernmental organization with a membership of 191 Member States and Territories. It originated from the International Meteorological Organization (IMO), which was founded in 1873. Established by the ratification of the WMO Convention on 23 March 1950, WMO became the specialised agency of the United Nations for meteorology (weather and climate), operational hydrology and related geophysical sciences a year later. Its current Secretary-General is Petteri Taalas and the President of the World Meteorological Congress, its supreme body, is David Grimes. The Organization is headquartered in Geneva, Switzerland. 

The World Meteorological Organization (WMO) is a specialized agency of the United Nations. It is the UN system's authoritative voice on the state and behavior of the Earth's atmosphere, its interaction with the oceans, the climate it produces and the resulting distribution of water resources. 

WMO has a membership of 191 Member States and Territories as of February 2014. The Convention of the World Meteorological Organization was signed 11 October 1947 and established upon ratification on 23 March 1950. WMO became the specialized agency of the United Nations in 1951 for meteorology (weather and climate), operational hydrology and related geophysical sciences. It originated from the International Meteorological Organization (IMO), which was founded in 1873. (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Here are a few examples of questions and answers:

Question: What is meteorology?
Guess: weather and climate

Question: What does WMO stand for?
Guess: World Meteorological Organization

Question: When was it created?
Guess: 1873

Question: How many members does it have?
Guess: 191 Member States and Territories

Question: When was it established by ratification?
Guess: 23 March 1950,

Question: Is it part of the United Nations?
Guess: yes

Now answer the following question in the same format.

Question: What kind of agency is it, within the United Nations?

specialised agency