First Hawaiian Hurricane Landfall in 22 Years

Ben Freeston

by on

Four Tropical Storms wall to wall across the Pacific with two impacting Hawaii Directly

Four Tropical Storms wall to wall across the Pacific with two impacting Hawaii Directly

© 2014 - NOAA / JMA

As Hurricane Iselle becomes the first storm of it's kind to make Hawaiian landfall in 22 years and Hurricane Julio following hot on it's heels, we break down the situation and the surf potential.

A slow start to the Atlantic Hurricane season is mirrored with a particularly active Pacific season with as many named storms by early August as we'd normally expect by September. The instrument of both is likely a slowly developing El Nino. Our forecaster Stefan Brunhuber breaks it down:

"Since spring 2012, the eastern Pacific ocean has been in a neutral phase, but according to the latest reports, there’s now a chance of more than 65 percent that equatorial waters in the Pacific will warm sufficiently to meet the criteria for an El Niño. The fact that water temperatures have already risen above the normal level suggests we're already likely to see an effect and does signal that we're ending a phase of relatively low Pacific activity since 1995. El Nino modifies the typical trade wind pattern increasing vertical wind shear in the Atlantic, destroying storms before they have a chance to form properly, but decreasing this same wind shear in the Pacific."

As with the sequence of incredible storms that pounded through the Atlantic this winter, it's tempting to see a repeat event as exceptionally unusual. In reality the odds of a storm like Julio following Iselle are slightly lower than for an unrelated event for two reasons: The first is simply that the larger scale atmospheric cycles that drove the first storm are slow to change. In this case a slowly developing El Nino is a contributory factor for the above active season we're seeing, as predicted. Secondly, the first storm can have a steering effect on the one that follows; creating a path of atmospheric instability that tows the seconds storm behind it.

In terms of outlook for surf, a landfall storm is never going to get too many surfers excited. Hurricane Iselle is passing over the Big Island as we write this bringing strong winds, rain and Easterly wind swell. However on the latest forecast, Hurricane Julio looks more interesting from a surfing perspective. Likely to pass to the North of the Islands there could be an opportunity for surf on otherwise seasonally dormant North Shore spots as well as larger surf for East facing breaks - all accompanied by light winds as a best case. As with any Hurricane swell, the storms path and intensity are subject to change and a modest change in track or intensity could have significant impacts on the local surf prospects.

East Facing Oahu Surf Forecast

Clearly visible is the remains of hurricane Iselle swell then the next pulse from Hurricane Julio

Clearly visible is the remains of hurricane Iselle swell then the next pulse from Hurricane Julio

© 2014 - MSW

North Shore Oahu Surf Forecast

More likely to change this forecast for the North Shore shows a modest but unseasonal side swipe from Hurricane Julio if it passes on it's predicted northern track. These forecasts can undercall for smaller intense storms so it's definitely worth a careful watch.

More likely to change this forecast for the North Shore shows a modest but unseasonal side swipe from Hurricane Julio if it passes on it's predicted northern track. These forecasts can undercall for smaller intense storms so it's definitely worth a careful watch.

© 2014 - MSW

Hurricane Iselle Forecast Validation

Satellite validation of the Hurricane Iselle forecast shows good correlation between the MSW model and the actual swell.

Satellite validation of the Hurricane Iselle forecast shows good correlation between the MSW model and the actual swell.

© 2014 - MSW / NASA - JASON