A surface ridge far to the north of the Hawaiian Islands continues to produce light to moderate trade winds across the state.
An upper level trough shown on water vapor imagery lingers northwest of the state with a subtropical jet stream blowing cirrus clouds across the islands from southwest to northeast.
Two tropical cyclones show up in the Hawaii region this evening.
Erick is currently a weakening tropical depression roughly 510 miles southwest of Lihue moving west-northwest at 14 MPH.
Flossie is currently a Tropical Storm centered roughly 610 miles east of Hilo moving west at 13 MPH.
On Sunday, expect typical weather from light to moderate trade winds with passing showers favoring windward and mauka areas in the overnight to early morning hours.
Monday and Tuesday, Tropical Cyclone Flossie approaches the islands from the east bringing up deeper tropical moisture into the islands.
Flossie’s more northerly storm track differs from Erick’s southerly path which should bring up more unsettled weather into the islands spreading from east to west through Wednesday as it passes north of the state.
Light winds with hot and humid conditions are also expected as this tropical system passes to the north.
The upper level ridge will also weaken as this tropical air mass moves into the area, increasing the height of the trade wind inversion up to the 8000 to 10000 foot level.
On Wednesday we transition back to a more stable trade wind weather regime with higher pressure building in from the east as Flossie lifts northwestward.
Expect increasing trade winds, lower humidity levels, and a general drying trend spreading slowly westward across the islands.
Thursday and Friday, a drier trade wind weather pattern develops through Friday morning as a strong ridge aloft will keep subsidence inversion heights in the 5000 to 7000 foot range.
By Friday afternoon another 700 MB trough moves into the Big Island from the east.
This low level trough will increase shower activity along windward slopes of Hawaii and Maui Counties through Saturday morning.
These enhanced showers will drift westward with this trough into the smaller islands from Saturday afternoon into Sunday.
The timing of these showers may change a bit this far out in the forecast cycle.