awips2/edexOsgi/com.raytheon.uf.common.dataplugin.obs/utility/common_static/base/derivedParameters/definitions/Precip3Hr.xml

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<DerivedParameter unit="in" name="Precip3Hr" abbreviation="Precip3Hr">
    <Method name="MetarPrecip">
        <Field abbreviation="precip3Hour"/>
        <Field abbreviation="accum_precip1Hour3"/>
    </Method>
</DerivedParameter>