Major Hurricane Amanda Possible Product of El Nino

It is possible that the record-breaking hurricane Amanda in the East Pacific is a product of the incoming El Nino.

Major Hurricane Amanda on May 25th

Amanda formed as a tropical depression on Thursday, May 22nd, where forecasts had the system staying at either tropical storm or weak hurricane strength for the length of its life. However, on Saturday, Amanda went from a strengthening tropical storm on the first bulletin of the day to a major hurricane by the final bulletin of the day from the National Hurricane Center. This rapid intensification continued until Amanda was declared the strongest May East Pacific hurricane on record in the satellite era on Sunday.

The sample size here is so small, just a single storm, but given this record having been set, it may be time to examine whether this storm was aided by the developing El Nino.

Shown above is the most recent image of sea surface temperature anomalies. We can see the El Nino signature in this graphic, shown by the band of positive SST anomalies extending from the waters off Ecuador to Oceania. A typical El Nino aligns global winds so that wind shear, a primary enemy of hurricanes everywhere, is increased in the Atlantic. This is why 'El Nino' and 'below-normal hurricane season' tend to go hand in hand. On the East Pacific side, wind shear is decreased, leading to additional opportunities for tropical cyclone formation.

This is why I raise the question of if Amanda was influenced by the oncoming El Nino; I personally believe that is the case. However, considering our sample size is next to nothing with just a single storm, we'll have to wait until the end of the cyclone season to determine what influence, if any, this El Nino wielded on the broader scale.

Andrew