Seventh Meeting February 26 2007 Intense Attribution Period (IAP) 15 November 2006 - 15 April 2007.

Seventh Meeting February 26 2007

Intense Attribution Period (IAP) 15 November 2006 - 15 April 2007

Current Attribution Challenges

•Enter La Niña!

Current Attribution Challenges

•Thermocline shallowing in the east Pacific……La Niña’s antecedent?

Current Attribution Challenges Back to the Future?

Current Attribution Challenges•What is the climate impact of the current state of world oceans?

OLR

Current Attribution Challenges•What is the climate impact of the current state of world oceans?

OLR

200 mb Z

Nov-Jan 2007

OBS

GFS-GOGA

GFS 200 mb Z Nov-Jan

2007

El Nino Comp

CCM3 200 Z Nov-Jan

Current Attribution Challenges•What is the origin of warm Atlantic SSTs in 2006/2007?

Std dev of annual variations= 0.25°C

Current Attribution Challenges•What is the origin of warm Atlantic SSTs in 2006/2007?

January 2007 SST Anomaly (NCEP)

Temp Anomaly 5m & 45 m (GODAS)

Upward latent heat flux anomaly

Dec06 - Jan07

CoolingOcean

Temp Anomaly & Climatology

Oct 2006 Ave 5°N-15°N

Atlantic SST anomaly 1980-2006

Ave 5N-15N

SLP Anomaly Dec06-Jan07

Qlh Jan anomaly

Current Attribution Challenges•What is the climate impact of warm Atlantic SSTs in 2006?

Current Attribution Challenges•What is the climate impact of warm Atlantic SSTs in 2006-2007?

Current Attribution Challenges

•What are the December 2006 -present pcpn anomalies?

Precipitation

Current Attribution Challenges• How do we explain the success/failure of seasonal outlooks?

December - February 2007 Outlook

Current Attribution Challenges

•What are the 1 Jan 2007 -present temp anomalies?

Temperature

Current Attribution Challenges• How do we explain the success/failure of seasonal outlooks?

December - February 2007 Outlook

Current Attribution Challenges

•What are the 1 Feb 2007 -present temp anomalies?

P&T

Current Attribution Challenges• How do we explain the success/failure of seasonal outlooks?

February-April 2007 Outlook

‘Crashing’ El Niño composites & latest AMJ SWcasts more consistent with it

Klaus Wolter - 26feb07

• Size of Niño 3/3.4 drop since early December vs. other cases• T&P composites in U.S. for ‘crashing’ El Niños

• SWcasts for April-June are trending downward

Recent Niño time seriesThe 2006-07 El Niño is ‘crashing’ fast in key Niño regions 3 and 3.4. A drop of about 1C in two months is not completely unprecedented, however.

Analog years can be defined by requiring an initial (December) SST anomalies of 0.5-2.5C, followed by a 2-3 month drop of 1C (0.9C) for Niño 3 (3.4), respectively. Fastest drops were in 1964, 66, 73, and 03. Other cases used: 52, 70, 88, and 95.

Spring composite for ‘crashing’ El NiñosIf you superimpose warming trends in March (large in Western U.S.), March may be rated ‘EC’ for SW, warm elsewhere.

Compared to ‘regular’ El Niño Marches, this one is not as bullish about precip. It is ‘wet’ around here mainly due to 2003.

Spring composite for ‘crashing’ El NiñosMarch through May looks quite similar to March in temperature composites, possibly warmer in SE U.S.

Note the lack of moisture in New Mexico and Texas!

Spring composite for ‘crashing’ El NiñosClassic El Niño temperature associations (left), and abundant moisture for spring in southwest (bottom).

Spring composite for ‘crashing’ El NiñosTemperature-wise, still looks like classic El Niño (left), but one should superimpose the warming trend.

A vestige of above-normal moisture west of here, but mostly under +0.5 sigma, not significant!

Spring composite for ‘crashing’ El NiñosClassic El Niño temperature associations (left), and abundant moisture for spring in southwest (bottom) lingers into April-June.

Downward trend in SWcasts