Puna Weather
Tuesday 22nd September 2026
Today very humid with scattered to numerous showers and moderate east or northeast winds.
Wednesday through Saturday very humid with heavy rain and moderate to breezy easterly winds. Flooding is likely.
This morning we have substantial easterly shear over ex-TD 15E keeping the storm from organizing deep convection over it's center of rotation, and this is preventing the storm for strengthening for the moment.
All models move the storm to a point south of our island and stall its westward progress there Thursday and Friday.
Today's GFS model output has a notable change from yesterday's. The mid/upper-level trough to our northwest Thursday through Saturday is now shown farther to the west. As such, the more recent models show high shear also shifted farther to the west, leaving less shear over us and to our southeast. This would likely allow for the storm to organize some while it is stalled to the south of our island.
The GFS brings the storm to hurricane strength under these favorable conditions, but keeps the storm south of our island. The ECMWF only strengthens the storm to a tropical depression (much weaker), but takes the low over our island after the stall.
Under both scenarios we would see an increase in onshore winds, but not likely to the point of widespread damage. Under both scenarios we would see multiple consecutive days of heavy flooding rains.
A slight shift north in the GFS or a stronger ECMWF solution could bring stronger winds to our island... this bears watching.
Due to the length of the heavy rain widespread flooding is looking likely.
I will shift to 2 posts per day until the threat from this storm passes.
