Spawns of El Nino? Hurricanes Iselle and Julio Aim For Hawaii
Cyclone Center is tracking two storms as we classify this afternoon.
It has been quite a remarkable week in the eastern and central Pacific that has culminated in two hurricanes taking aim at the Hawaiian Islands today. Hurricane Iselle has shown herself to be quite resilient as she has maintained her hurricane strength despite moving over cooler ocean waters. Hurricane warnings are out for the big island as residents prepare for a significant event. Meanwhile, Hurricane Julio is following close behind, continuing to intensify despite his movement over cooler waters. The graphic below from the Central Pacific Hurricane Center shows the likelihood of significant winds over the next few days in the islands:
The black areas on the graph show where strong winds are certain. The black area on the left is from Iselle, while the one to the right is from Hurricane Julio. Unlike his big sister, Julio is not expected to track directly over the big island – but rather miss a bit to the north.
We’ve written about significant Hawaiian hurricanes before. Most occur during El Nino years, which is a time when the ocean temperatures in the central and eastern Pacific are warmer than normal. These warmer waters provide additional energy into the tropical cyclones, allowing them to maintain their strength for longer periods of time and to move across wider areas of the ocean. Usually, ocean temperatures near Hawaii are near 24-25 degrees Celsius (C), which is barely warm enough to sustain a minimal tropical cyclone. Current temperatures are between 26 and 27 degrees C, making for a much better experience for these tempests.
– Chris Hennon is part of the Cyclone Center Science Team and Associate Professor of Atmospheric Sciences at the University of North Carolina at Asheville