Hurricane season gets under way in the Eastern Pacific

  • Overview of Amanda, as captured by NASA's Aqua satellite.

    Latest forecast track for what is now tropical storm Amanda. Source: Joint Typhoon Warning Center.

    Map showing cumulative rainfall over Central America through the next 84 hours, as modelled by GFS.

  • Hurricane season gets under way in the Eastern Pacific
    29.05.2014 13:05


    This week saw the first named storm of the year as Hurricane Amanda formed in the Eastern Pacific, attaining category 4 status for a time with peak winds of 155mph.

    Amanda started as a cluster of heavy showers and thunderstorms last week approximately 650 miles south-west of Manzanillo, Mexico, and encountered favourable conditions for tropical cyclone development. The basic ingredients of warm sea surface temperatures, weak atmospheric wind shear and a small component of Coriolis Force were met and by Saturday the system reached hurricane intensity. Peak winds occurred on Sunday and apart from a brief re-strengthening on Tuesday, Amanda weakened through the course of this week.

    Although the hurricane season officially runs from 15th May each year in the Eastern Pacific, this week’s storm has been unusual as major hurricanes are not typically expected at this time of year. Indeed, the observed wind speeds have surpassed the previous record for May (Hurricane Adolph, 29th May 2001 with winds of 145mph) making it the strongest ever May hurricane.

    Luckily, Amanda spent all of her life cycle hundreds of miles offshore from California and Mexico limiting the storm impact, but even as it continues to weaken, the remnants are likely to bring disruption. Current projections estimate that as the now tropical storm (and soon to be ‘tropical depression’) moves eastwards, the residual atmospheric moisture is likely to bring high rainfall totals to parts of Central America this weekend (see map). Over 100mm of rain could be recorded in the next few days, especially in southern Mexico and Guatemala.

    Looking ahead through the rest of the season, the National Oceanographic and Atmospheric Administration (NOAA) have forecast a near-normal to above-normal hurricane season in the Eastern Pacific, especially with the prospect of El Niño returning this year. Conversely, the Atlantic basin is expected to see near-normal or below-normal hurricane activity.


    By: Nick Prebble