Tropical Storms Invade Hawaiian Waters: The Role of El Nino

Normally, tropical storms and hurricanes avoid the area of the Hawaiian Islands.  

Why?   Because the nearby Pacific is usually too cool!  

In general, surface temperatures must reach at least 80°F (26.5°C) to sustain tropical storm development.

This year, due to a very strong El Nino, temperatures south and east of Hawaii are 1-2 C above normal (see map of differences from normal for sea surface temperature)

As shown by a more detailed, close-in map, the 27C line just reaches Hawaii.    A "warm enough" bath is open.

No wonder tropical storms can approach Hawaii this year!

The effects of the warm water have been dramatic.

Consider satellite imagery from yesterday afternoon...and be prepared to be impressed!

A high-resolution satellite image shows three hurricanes/tropical storms over the eastern Pacific, with a red arrow pointing to the Big Island.  Wow.

Here is an infrared image of the storms.   Amazing.

Even more amazing is a series of forecast maps of evolution of the tropical storms.  I will show you maps of atmospheric moisture through depth.

Today at 11 AM, the swirls of moisture around three tropical storms are evident.  Stunning.

On Saturday morning, they are still there, with one storm passing south of the Hawaiian island

On Sunday morning, the western storm starts moving northeastward towards Hawaii!  Some moisture from the eastern storm extends into southern California, which is going to get some rain as a result

Now the most amazing thing.   The two eastward storms start to interact on Monday.

Then the combined system starts to move northwest on Tuesday.

The storm's crazy movement near Hawaii is reflected in the total precipitation over the next 10 days. You can see the northward jog, followed by a turn to the east.     Quite unusual!

A great time to visit Kauai if you are meteorologically inclined. 😊