Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
343 AM EDT Sat May 13 2023

Valid 00Z Sun May 14 2023 - 00Z Sun May 21 2023

Initially weak trade winds on Saturday should give way to
strengthening northeasterly winds late Saturday into Sunday as a
cold front pushes south across the state. While overall moisture
levels are lackluster, there could certainly be enough low-level
moisture pooling near the front to enhance shower and cloud
coverage with the front. Moderate (to perhaps breezy at times)
trades with some northerly component should continue through the
first part of next week behind the front and with a surface high
to the northwest of the state. Any scattered showers would likely
favor windward areas, especially over the Big Island, but as the
front dissipates not many showers are expected.

By mid- to late next week, model guidance continues to indicate
the possibility of the pattern becoming much wetter across Hawaii,
as an upper trough axis sets up to the west of the state, which
could draw in higher moisture levels and provide for increasing
shower coverage and perhaps some heavy rain. This would also turn
winds more southerly and weaken them overall. There are still
notable model differences in terms of timing, placement, and
amounts of precipitation given the differences in the upper/trough
low pattern though. The CMC and CMC ensemble mean were among the
most aggressive with these features. So this pattern change will
continue to be monitored as model guidance variations lead to low
confidence at this time.

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