First off, here’s verification of the April 24th run focused on the time period from May 1st to May 8th.

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Last night’s forecast from the same model, extending into the early days of June.

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As referenced in an earlier post, endorsement of a possible El Nino event later this year is waffling as we grind through the usual spring predictability barrier. The probabilistic chance of an El Nino has been dropping and is now only slightly favoured over La Nada as of the very latest from the CPC/IRI.

We’ll continue to monitor this over the months to come.

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ENSO-neutral persisted during April, with near-average sea surface temperatures (SSTs) observed across the central equatorial Pacific and above-average SSTs in the eastern Pacific.

Most models predict the onset of El Niño (3-month average Niño-3.4 index at or greater than 0.5°C) during the Northern Hemisphere summer. However, the NCEP CFSv2 and most of the statistical models are more conservative and indicate that while Niño-3.4 index may be near or greater than +0.5°C for several months, the warmth may not last long enough to qualify as an El Niño episode (5 consecutive overlapping seasons) and/or may not significantly impact the atmospheric circulation. Relative to last month, the forecaster consensus reflects slightly lower chances of El Niño (~45%), in part due to the conflicting model guidance and lack of a clear shift toward El Niño in the observational data.

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