Synopsis: ENSO-neutral is favored into the Northern Hemisphere fall 2013.
AUGUST 8th, 2013 UPDATE from LiveWeatherBlogs.com
ENSO-neutral conditions persisted during July 2013, as reflected by near-average sea surface temperatures (SSTs) across the central and east-central equatorial Pacific and below-average SSTs in the eastern Pacific (Fig. 1). Consistent with this pattern, weekly Niño-4 and Niño-3.4 values were between -0.5° and 0°C, while Niño-3 and Niño-1+2 indices remained cooler than -0.5°C (Fig. 2).
The oceanic heat content (average temperature in the upper 300m of the ocean) anomalies continued to be slightly above average during July (Fig. 3), due to the persistence of above-average sub-surface temperatures in most of the eastern half of the Pacific (Fig. 4). The low-level winds remained near average across the equatorial Pacific, while weak upper-level westerly anomalies persisted in the western Pacific. Convection continued to be enhanced over Indonesia and suppressed in the central part of the basin (Fig. 5). Collectively, these atmospheric and oceanic conditions reflect ENSO-neutral.
The waters off the coast of Mexico are warm and continue to spawn a now active Pacific Hurricane season from Mexico to Hawaii. The ocean flow above shows warmer waters pooling in the Western Pacific Ocean at this hour and this may be a “small” sign of a transport east over the next 6 months.
The ECMWF or Euro model still shows a weak El Nino ENSO this winter but other models sit in the NEUTRAL to even La Nina world as of this last day of July.
We here at Liveweatherblogs will continue the idea of a trend to a neutral pattern through the Fall 2013 but a slight upward tick to a weak El Nino by January 2014.
As you recall last year many experts trending to a weak to moderate El Nino and it never came to life so expect the unexpected this winter. Projecting El Nino esp. a weak one can be very tricky simply due to the lack of knowledge we still have on this fairly new discovery.
Read the full El Niño 2013 Breakdown here: