Is the Kilauea Volcano in Hawaii dumping feet of rain?
The Kilauea volcano in Hawaii erupted in early May 2018. Earlier this month, a blog reader pointed out a
of Doppler-estimated rainfall on the South Shore radar (PHWA) in just over a day. The radar, I assumed, must be overestimating rainfall because of the particles in the smoke and steam from the volcano vent (volcano is off the southwest side of the map). I didn't have time to further investigate, so I put the map aside.

On July 7, it happened again and I compared the estimate to the rainfall amounts reported by the CoCoRAHs network. The amounts roughly matched, with a station 3 miles southeast of Pahoa reporting 11 inches on July 3 and another station 2.7 miles SSE of Pahoa racking up 13.67 inches the same day. Amazing!

Then I remembered that parts of eastern Hawaii are famous for heavy rain and a check of the Rainfall Atlas of Hawaii shows the area receiving between 3,000-7,000 mm (inches) per year.

That averages out to 118-276 inches (10 to 23 feet) of rain per year, or about 1 to 2 feet per month, so these amounts are not unusual at all. As a final sanity check, the June 2018 hydrology summary for the Big Island did not show anything unusual, and Kilauea was not mentioned. It's just par for the course for the southeast part of the island!
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