Saturday, June 13, 2015

"El Niño Continues to Ramp Up"

From Wunderblog:
The latest updates from NOAA (see PDF) and the Australian Bureau of Meteorology confirm that the El Niño event that began in earnest this spring continues to build. NOAA reports that sea-surface temperatures (SSTs) in the closely watched Niño3.4 region of the eastern tropical Pacific were 1.2°C above average last week, well into the range associated with moderate El Niño events (+1.0°C to +1.5°C). Based on another marker, the Multivariate ENSO Index, this El Niño event is already into the “strong” category. All of the Niño monitoring regions had SSTs of at least 1.2°C above average last week, making for the most widespread oceanic warmth since the landmark El Niño event of 1997–98. Policymakers and investors are already taking note of the potential implications of the intensifying El Niño for agriculture and the economy.

Computer models are in firm agreement that El Niño conditions will strengthen further during the latter part of 2015. All eight of the international models tracked by BOM show Niño3.4 readings of 1.5°C or higher by October (see Figure 2), and several exceed 2.0°C, suggesting that the strongest event since 1997–98 may well be in the cards. Some models predicted that a significant El Niño would emerge in mid-2014, but that didn’t happen, largely because the atmosphere failed to respond to oceanic shifts that often kick off El Niño. This time, the atmosphere and ocean are much more in sync, so we can put more trust in the current model outlooks—especially now that we’re past the “spring predictability barrier” that makes early-year forecasts of El Niño so tough. In today’s update, NOAA is calling for a greater than 90% chance that El Niño will continue through the northern fall of 2015, and around an 85% chance it will last through the winter of

What will summer bring us?
On average, El Niño’s impacts on U.S. weather are much stronger in winter than in summer. As NOAA’s Anthony Barnston puts it in a recent ENSO Blog post, “while El Niño is the 800-pound gorilla in winter forecasts in the U.S., it is more like a tame, 6-pound Chihuahua in summer.” Barnston cites two reasons for this:...MORE
California needs to get through the next five months and El Nino needs to continue to strengthen.
Lifted from the comments section:

Generalized effects during Northern Hemisphere winter.