2008-09 climate recap and outlook for winter 2009-10 eric salathé jisao climate impacts group...

2008-09 Climate Recap and Outlook for Winter 2009-102008-09 Climate Recap and Outlook for Winter 2009-10

Eric SalathéJISAO Climate Impacts Group

University of Washington

Recent Climate News: Global Temperatures

From NASA GISS

Recent Climate News: Arctic Sea Ice

Recent Climate News: Arctic Sea Ice

Recent Climate News: CLIMATECHANGE

Global Risks, Challenges & Decisions COPENHAGEN 2009, 10-12 March

CO2 Emissions

http://climatecongress.ku.dk/

Recent Climate News: CLIMATECHANGE

Global Risks, Challenges & Decisions COPENHAGEN 2009, 10-12 March

Global Temperature

Recent Climate News: CLIMATECHANGE

Global Risks, Challenges & Decisions COPENHAGEN 2009, 10-12 March

Sea Level

U.S. Temperature and Precipitation Departures During the Last 30 and 90 Days

30-day (ending 26 Sept 2009) temperature departures (degree C)

Last 30 Days30-day (ending 27 Sept 2009) % of average precipitation

90-day (ending 27 Sept 2009) % of average precipitation

90-day (ending 26 Sept 2009) temperature departures (degree C)

Last 90 Days

Mountain Snow and Precipitation

Salmon Meadows (Northeast Cascades)

Central Cascades

Northeast Cascades

U.S. Drought Conditions

U.S. Drought Conditions

El Niño Outlook

• El Niño is present across the equatorial Pacific Ocean.

• Sea surface temperatures (SST) were at least 1.0ºC above-average across much of the central and east-central equatorial Pacific.

• Based on current observations and dynamical model forecasts, El Niño is expected to strengthen and last through Northern Hemisphere winter 2009-10.

Update prepared byClimate Prediction Center / NCEP

28 September 2009

Niño Region SST Departures (oC) Recent Evolution

NOAA Operational Definitions for El Niño and La Niña

El Niño: characterized by a positive ONI greater than or equal to +0.5°C.

La Niña: characterized by a negative ONI less than or equal to -0.5°C.

By historical standards, to be classified as a full-fledged El Niño or La Niña episode, these thresholds must be exceeded for a period of at least 5 consecutive overlapping 3-month seasons.

CPC considers El Niño or La Niña conditions to occur when the monthly Niño3.4 SST departures meet or exceed +/- 0.5°C along with consistent atmospheric features. These anomalies must also be forecasted to persist for 3 consecutive months.

ONI (oC): Evolution since 1950

El Niño

La Niña

neutral

The most recent ONI value (June – August 2009) is +0.7oC.

Pacific Niño 3.4 SST Outlook

Figure provided by the International Research Institute (IRI) for Climate and Society (updated 14 Sept 2009).

• Most ENSO models indicate El Niño will continue through the Northern Hemisphere winter 2009-10.• The models disagree on the eventual strength of El Niño (SST anomalies ranging from +0.5°C to +2.0°C), but a majority indicate at least a moderate strength El Niño (greater than +1.0°C) during November-December-January 2009-10.

The seasonal outlooks combine the effects of long-term trends, soil moisture, and, when appropriate, the ENSO cycle.

U. S. Seasonal OutlooksOctober – December 2009

The seasonal outlooks combine the effects of long-term trends, soil moisture, and, when appropriate, the ENSO cycle.

U. S. Seasonal OutlooksJanuary – March 2010

U.S. Precipitation Departures (mm) and Frequency of Occurrence (%)

for El Niño during Oct.-Dec.

FREQUENCY (right panel) indicates the percentage of El Niño years that the indicated departure (left panel) occurred. For example, below-average seasonal precipitation over western Washington occurred in 70-80% of El Niño years – 13-14 out of 18.

U.S. Temperature Departures (°C) and Frequency of Occurrence (%)

for El Niño during Oct.-Dec.

Summary

• El Niño is present across the equatorial Pacific Ocean.

• Sea surface temperatures (SST) were at least 1.0ºC above-average across much of the central and east-central equatorial Pacific.

• Based on current observations and dynamical model forecasts, El Niño is expected to strengthen and last through Northern Hemisphere winter 2009-10.