MHL Spectra Analysis vs Primary Swell

Unpredictable's picture
Unpredictable started the topic in Tuesday, 5 Mar 2019 at 11:38pm

So I've been trying to understand this for some time and conditions are currently perfect to ask this question. MHL's spectra graph is a useful tool but it sometimes leaves me confused as it often seems to ignore the dominant swell in the water. Today is a perfect example, Primary swell is ENE on MHL's own graph and any other website you care to check and there is no other swells in the water, yet the spectra shows energy from the NE and SE and almost no energy around 90 degrees. Does anyone know what causes these anomalies?

Note: Conditions have shifted slightly between writing and posting. Swell direction was close to 90 degrees and now shifted to 65. Still not well represented on spectra.