What is the difference between A01 and A02 in an Auto METAR report?

What is the difference between A01 and A02 in an Auto METAR report?

• A. A01 does not have a precipitation discriminator i.e. the unit cannot determine the difference between liquid or frozen precipitation.
• B. A01 lacks a precipitation discriminator.
• C. A01 indicates liquid precipitation only.
• D. A02 indicates frozen precipitation only.

Answer: (B)

The essential distinction is whether the automated weather observation system includes a precipitation discriminator. A01 refers to an automated station that does not have this discriminator, so it cannot identify whether precipitation is liquid or frozen. A02, on the other hand, has the discriminator and can determine precipitation type. Therefore, the difference is that A01 lacks a precipitation discriminator. The other statements either describe a consequence of that lack or misstate what A02 indicates.

The essential distinction is whether the automated weather observation system includes a precipitation discriminator. A01 refers to an automated station that does not have this discriminator, so it cannot identify whether precipitation is liquid or frozen. A02, on the other hand, has the discriminator and can determine precipitation type.

Therefore, the difference is that A01 lacks a precipitation discriminator. The other statements either describe a consequence of that lack or misstate what A02 indicates.