Puna Weather
Tuesday 19th May 2026
Today and Wednesday moderate to breezy easterly trade winds and humid with scattered showers, mostly during the night and early morning hours.
Thursday through Sunday moderate to breezy easterly trade winds with only a few showers.
A persistent broad surface high to our north maintains easterly trade flow over us for the next week or more. Upstream low level moisture to our will keep windward showers in the forecast through early Wednesday. After Wednesday our upstream flow dries out with dew points dropping from the lower 70s into the mid-60s. Aloft dry and stable northerly flow (500hPa chart) also supports the reduction in showers.
Now that we're moving into a summer pattern we're keeping an eye on the MJO. Last time it passed overhead it helped to spawn Typhoon Sinlaku which broke records and helped to strengthen a westerly wind burst in the western Pacific leading to a downwelling Kelvin wave (warm water below the surface which travels east) reinforcing our transition to an El Nino state.
The MJO is forecast to pass over us again in 2-3 weeks. Sea surface temperatures to our south are running well above normal and the GFS shows a brief pause in upper level shear around that time, possibly leading to a period of tropical moisture moving north and over us. I'll be keeping an eye on this as we get closer to June 1, which is coincidentally the start of the central Pacific hurricane season.
