Question

what role does the automated surface observing systems (asos) play in weather forecasting?
it is a fleet of weather balloons.
it is a system of radar sensors used to track storms.
it is the nations primary weather - observing network.
it provides weather reports much like the national weather service.

Explanation:

ASOS is a network of weather - observing stations across the nation. It is not a fleet of weather balloons (weather balloons are a different method of weather observation). It is not just a system of radar sensors (radar is part of it but not the whole). And it is not just providing reports like the National Weather Service (the National Weather Service uses data from ASOS among other sources). ASOS is the nation's primary weather - observing network.

Answer:

It is the nation's primary weather - observing network.