@Shawn-07472c89-c894-4d3e-a37d-f0fc07bbeb37
RA stands for RAIN.
-RA, light rain
+RA, heavy rain
TSRA, thunderstorm with rain.
Those are some of the abbreviations used in METARs
(format for reporting airport's weather information).
https://en.m.wikipedia.org/wiki/METAR