Wednesday, June 18, 2014

Despite Recent Stories to the Contrary El Niño Has Not Yet Arrived

A few days ago there were a bunch of "El Nino is 'already here'" headlines. They are incorrect
From Australia's Bureau of Meteorology: 

ENSO Wrap-Up
Pacific Ocean remains primed for an El Niño in 2014
Issued on Tuesday 17 June 2014 |
Warming of the tropical Pacific Ocean over the past several months has primed the climate system for an El Niño in 2014. However, in the absence of the necessary atmospheric response, warming has levelled off in recent weeks. Positive Southern Oscillation Index values and large areas of warm water in the western Pacific and off northwestern Australia are also counter to typical El Niño development.

Despite recent observations and some easing in the model outlooks, climate models surveyed by the Bureau still indicate El Niño is likely to develop by spring 2014. The Bureau's ENSO Tracker remains at El Niño ALERT, indicating at least a 70% chance of El Niño developing in 2014.

For Australia, El Niño is often associated with below-average rainfall over southern and eastern inland areas and above-average daytime temperatures over southern parts of the continent.

The Indian Ocean Dipole (IOD) is currently neutral. Model outlooks suggest the IOD is most likely to remain neutral through winter and spring. Positive IOD events often coincide with El Niño and are typically associated with large parts of southern and central Australia experiencing lower rainfall than usual.
Although most readers know this stuff I'll run through it again for folks new to the site.
An El Niño is defined as three overlapping three-month periods i.e. five consecutive months with sea-surface temperature anomalies of at least 0.5oC above average in the Nino 3.4 region in the east-central equatorial Pacific [between 5oN-5oS and 170oW-120oW].
El Niño conditions are the same 0.5oC anomaly without the time element.
Australia's Bureau of Meteorology uses +0.8°C as their threshold.

Here is NOAA's latest report dated June 16:
ENSO: Recent Evolution,Current Status and Predictions
(33 page PDF)

Here is NOAA's latest Diagnostic Discussion, 5 June 2014:
(6 page PDF)

And for orientation, the Nino regions:
See also:
"U.S. Private Weather Agencies Predict WEAK El Niño in 2014"
"What If We're Waiting For the Wrong Kind of El Niño? Colorado State Bumps Up Their Estimate Of The Hurricane Season"