Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
823 AM EDT Tue May 23 2017

Valid 00Z Wed May 24 2017 - 00Z Wed May 31 2017

06Z OPC surface analysis indicated a weakening stationary boundary
just north of Kauai that extended northeastward toward an upper
low (with a better-defined surface boundary). This front will wash
out during the day today (Tuesday) north of Hawai'i as a strong
high pressure (1038mb-1040mb) slides northeastward, but its
moisture axis will slowly sink southward. Showers will become a
bit more widespread over Kauai on Thursday but the GFS was mostly
wetter than the ECMWF. The pressure gradient will relax over the
rest of the week, allowing trades to decrease. By the weekend into
next week, heights will lower as a trough swings by to the
northeast of the region. Area will stay on the relative drier side
of the upper flow, with mainly scattered windward showers. Again,
the GFS (and GEFS) were a bit wetter than the ECMWF (and its
ensembles). Moisture may increase next week from the southeast per
the ensembles as heights rise a bit as well.


Fracasso