Hawaii Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
354 AM EDT Tue Apr 15 2025

Valid 00Z Wed 16 Apr 2025 - 00Z Wed 23 Apr 2025


Trades will gradually decrease on Tuesday while a surface trough 
starts developing over Hawaii. A large trough aloft will approach 
west of the state into midweek. Mean winds should veer more 
southeasterly in response to the trough, but are likely to be weak
enough at the surface that land and sea breezes dominate the 
pattern. The upper trough will push a surface cold front that 
stalls west of the state for the latter half of the week. Ahead of
the front, moisture will be drawn northward atop the islands and 
increase shower coverage. Precipitable water values could reach 
over the 90th percentile for this time of year at times. Plus the 
upper trough could allow for some instability to form to support 
potential thunderstorms. The wetter pattern should begin Wednesday
and peak across the state Thursday-Friday. 

Over the weekend, the upper trough is forecast to weaken and pull
away, while Pacific surface high pressure develops well north and
allows for trades to slowly resume. This may be a somewhat wet 
trade wind pattern through early next week as moisture lingers.


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