Why “Kona Weather” Sometimes Leads to DownpoursJuly 9, 2016, 8:58 AM HST · Updated July 8, 11:05 PM Meteorologist Malika Dudley · 0 Comments
Aloha, I’m Meteorologist Malika Dudley reporting from high in the sky today aboard a Blue Hawaiian Helicopter. We’re checking out our weather features from above. Today, we’re talking about what people refer to as “Kona weather” – this is when the lack of trade winds creates sticky, muggy conditions because of the high humidity levels and we even sometimes see periods of heavy localized rainfall.
What happens is the sun heats the land – we all know hot air rises – so the cooler air from out over the ocean rushes in to replace it. This is what we commonly refer to as an onshore sea breeze. As this air lifts, clouds form and if there is enough moisture in the air, we sometimes get brief periods of heavy downpours. This is what you’ll hear weather people call convection.
These rainfall episodes are often short-lived because as the sun sets and temperatures cool down, the reverse happens.
The land cools and the result is an offshore land breeze which clears our skies and pushes the clouds out to sea. With less clouds in the sky to trap the heat in like a blanket, we also see cooler temperatures during these types of weather conditions.
In the lee of our mountains – in that rain shadow we have along the Kihei coastline and Lahaina – this type of weather pattern is a daily occurrence. Haleakalā and the West Maui Mountains block our wind flow so the small circulation pattern of land and sea breezes dominates. It’s pretty clear when you look at the ocean. In the morning, it’s flat and glassy and as the sea breeze develops you’ll see white capping conditions take over.
Blue Hawaiian Helicopter Video Series also features…