Water vapor view of Hurricane Oho. (National Hurricane Center)

It’s not uncommon for the jet stream to sweep tropical weather systems like typhoons and hurricanes into the northern Pacific Ocean. But usually, when this happens, the storm quickly loses it tropical characteristics.

Meet Oho, the hurricane about 650 miles east-northeast of Honolulu, which may make history by reaching the North Pacific as a tropical storm.

“The current forecast track has the center of Oho potentially crossing longitude 140W into the area of responsibility of the National Hurricane Center in Miami Florida between 24 and 36 hours from now,” writes the Central Pacific Hurricane Center. “Should Oho actually cross into the northeastern Pacific basin as a tropical cyclone…this will be a rare occurrence…at least in the satellite era.”


Track forecast for Hurricane Oho (Central Pacific Hurricane Center)

Slate.com meteorologist Eric Holthaus notes that since 1850, “only one or two” tropical weather systems have managed such a course.

Ocean temperatures are unusually warm – up to 6 degrees F above normal – in this region, bumping up the likelihood of such a possibility. This area of warm water has persisted for over two years and has been dubbed “the blob.”

[Red crabs swarm Southern California, linked to ‘warm blob’ in Pacific]


Ocean temperature difference from normal. (NOAA)

However, once the storm moves north of about 40 degrees latitude on Thursday, water temperature rapidly decrease and it will inevitably transition into a mid-latitude (non-tropical) cyclone, powered by temperature contrasts rather than warm waters.

The storm is forecast to weaken during this transition; however, models suggest it may re-intensify near the coast of southeast Alaska and British Columbia around Friday as it goes through “an explosive deepening phase.”

“Confidence is increasing in a significant wind event for the southern panhandle and adjacent marine waters…with storm force winds possible,” writes the National Weather Service forecast office serving Juneau. “High winds-gusts at or above 60 mph not out of the question from Hydaburg to Ketchikan.”