Climate recap and outlookClimate recap and outlook

Nate Mantua, PhDUniversity of Washington

Center for Science in the Earth System - Climate Impacts Group

Boise, ID October 17, 2007

Nate Mantua, PhDUniversity of Washington

Center for Science in the Earth System - Climate Impacts Group

Boise, ID October 17, 2007

The CSES - Climate Impacts GroupThe CSES - Climate Impacts Group

•Goal: help the Pacific Northwest become more resilient to climate variations and climate change

• Supported by NOAA Climate Program Office as part of the Regional Integrated Science and Assessments (RISA) program

•Goal: help the Pacific Northwest become more resilient to climate variations and climate change

• Supported by NOAA Climate Program Office as part of the Regional Integrated Science and Assessments (RISA) program

http://cses.washington.edu/cig/

4444

Accumulated Precip for the past yearAccumulated Precip for the past year

Source:http://www.cpc.ncep.noaa.gov/products/global_monitoring/precipitation/

northwest_1yrprec.shtml

Accumulated Precip for the past yearAccumulated Precip for the past year

Source:http://www.cpc.ncep.noaa.gov/products/global_monitoring/precipitation/

northwest_1yrprec.shtml

Daily TemperaturesDaily Temperatures

+1.27ºC+1.27ºC

+0.95ºC+0.95ºC

2006-07 snow pack2006-07 snow pack

2006-07 snow pack2006-07 snow pack

June-July-August 2007 temperature June-July-August 2007 temperature anomaliesanomaliesJune-July-August 2007 temperature June-July-August 2007 temperature anomaliesanomalies

June-July-August 2007 standardized June-July-August 2007 standardized precipitation anomaliesprecipitation anomaliesJune-July-August 2007 standardized June-July-August 2007 standardized precipitation anomaliesprecipitation anomalies

Oct 1 estimated soil moisture percentilesOct 1 estimated soil moisture percentiles

• Courtesy of Andy Wood, University of Washington, data and images are available at

http://www.hydro.washington.ed

u/forecast/monitor

• Courtesy of Andy Wood, University of Washington, data and images are available at

http://www.hydro.washington.ed

u/forecast/monitor

Summer ocean conditionsSummer ocean conditionsSummer ocean conditionsSummer ocean conditions

Last year’s outlookLast year’s outlook

•a weak to moderate El Niñoa weak to moderate El Niño is likely for the next 2-3 seasons

•because of trendstrends and expectations for a weak to moderate intensity weak to moderate intensity El NiñoEl Niño, above-average fall/winter/spring temperatures are likely

• El Niño also tilts the odds in favor of a dry fall/winterdry fall/winter and below below average end-of-season snow packaverage end-of-season snow pack

•a weak to moderate El Niñoa weak to moderate El Niño is likely for the next 2-3 seasons

•because of trendstrends and expectations for a weak to moderate intensity weak to moderate intensity El NiñoEl Niño, above-average fall/winter/spring temperatures are likely

• El Niño also tilts the odds in favor of a dry fall/winterdry fall/winter and below below average end-of-season snow packaverage end-of-season snow pack

NOAA/CPC forecasts issued September 21, 2006NOAA/CPC forecasts issued September 21, 2006

OND precip JFM precip

http://cpc.ncep.noaa.govhttp://cpc.ncep.noaa.gov

Precip: observedPrecip: observed

http://cpc.ncep.noaa.govhttp://cpc.ncep.noaa.gov

NOAA/CPC forecasts issued September 21, 2006NOAA/CPC forecasts issued September 21, 2006

OND temperature JFM temperature

Temperature: observedTemperature: observed

21212121

This year…This year…

La Niña arrivingLa Niña arriving

• Tropical ocean temperatures have slid into La Niña territory

• Tropical ocean temperatures have slid into La Niña territory

Equatorial temperature anomalyEquatorial temperature anomaly

The latest ENSO forecastsThe latest ENSO forecasts

See http://iri.columbia.edu/climate/ENSOSee http://iri.columbia.edu/climate/ENSO

European Center

Forecast summaries

Typical winter Typical winter winds and jet winds and jet stream during stream during El Niño and La El Niño and La Niña wintersNiña winters

Average La Niña winter precip: 1916-2003

Average La Niña winter precip: 1916-2003

http://www.cses.washington.edu/cig/mapshttp://www.cses.washington.edu/cig/maps

PDO forecastPDO forecast

PDO forecast: drifting toward coolPDO forecast: drifting toward cool

http://www.esrl.noaa.gov/psd/

Pacific Ocean Outlook SummaryPacific Ocean Outlook Summary• Current forecasts rate La Niña as most

likely situation for 2007-08• PDO: Transiting to cool phase as La Niña

fades

• Current forecasts rate La Niña as most likely situation for 2007-08

• PDO: Transiting to cool phase as La Niña fades

Wet AutumnWet AutumnWet AutumnWet Autumn

TemperatureTemperature PrecipPrecip

Wet Winter… and possibly coolest in Wet Winter… and possibly coolest in years, but still only “EC”years, but still only “EC”Wet Winter… and possibly coolest in Wet Winter… and possibly coolest in years, but still only “EC”years, but still only “EC”

Another factor in seasonal forecastsAnother factor in seasonal forecasts

PNW December-January-February temperatures

The Bottom lineThe Bottom line

• moderate La Niña underway tilts the odds toward cool/wet, better-than-average snowpack•Additional influence from PDO might come too late to offset another factor…

– Persistent warming trends

• moderate La Niña underway tilts the odds toward cool/wet, better-than-average snowpack•Additional influence from PDO might come too late to offset another factor…

– Persistent warming trends

See http://www.cpc.ncep.noaa.gov

CPC Forecasts from Sept 20CPC Forecasts from Sept 20CPC Forecasts from Sept 20CPC Forecasts from Sept 20