Seasonal Climate Forecast June – August 2014 (Issued: May 21, 2014) This Product is Published by the Oregon Department of Agriculture (ODA), in Cooperation.

Seasonal Climate Seasonal Climate ForecastForecast

June – August 2014June – August 2014(Issued: May 21, 2014)(Issued: May 21, 2014)

This Product is Published by the OregonThis Product is Published by the OregonDepartment of Agriculture (ODA), in CooperationDepartment of Agriculture (ODA), in Cooperationwith the Oregon Department of Forestry (ODF).with the Oregon Department of Forestry (ODF).

Contact: ODF Meteorologist Pete ParsonsContact: ODF Meteorologist Pete Parsonsat 503-945-7448 [email protected] 503-945-7448 [email protected]

Get related Seasonal Climate Forecast information at Get related Seasonal Climate Forecast information at http://cms.oregon.gov/ODA/NRD/Pages/weather.aspx

This Product is Published by the OregonThis Product is Published by the OregonDepartment of Agriculture (ODA), in CooperationDepartment of Agriculture (ODA), in Cooperationwith the Oregon Department of Forestry (ODF).with the Oregon Department of Forestry (ODF).

Contact: ODF Meteorologist Pete ParsonsContact: ODF Meteorologist Pete Parsonsat 503-945-7448 [email protected] 503-945-7448 [email protected]

Get related Seasonal Climate Forecast information at Get related Seasonal Climate Forecast information at http://cms.oregon.gov/ODA/NRD/Pages/weather.aspx

Forecast Method Notes…Forecast Method Notes…

Analog years were obtained by tracking and Analog years were obtained by tracking and comparing a variety of indices over the past several comparing a variety of indices over the past several years (see years (see Forecasting Methods). Priority was ). Priority was given to years with sea-surface temperatures given to years with sea-surface temperatures (SSTs) (SSTs) most closely matching the current SSTsmost closely matching the current SSTs in in the equatorial Pacific Ocean.the equatorial Pacific Ocean. Analog years in the Analog years in the “Cool Phase” “Cool Phase” of the Pacific of the Pacific Decadal Oscillation (PDO) have been verifying Decadal Oscillation (PDO) have been verifying much better than years in the much better than years in the “Warm Phase,” “Warm Phase,” which which intuitively makes sense, because we are currently intuitively makes sense, because we are currently in the in the “Cool Phase”“Cool Phase” of the PDO. of the PDO. 2009 replaced 1957 as one of the top analog years 2009 replaced 1957 as one of the top analog years used to create this month’s forecast. The other used to create this month’s forecast. The other analog years (1963 & 1968) remained unchanged.analog years (1963 & 1968) remained unchanged.

El Niño Southern Oscillation El Niño Southern Oscillation (ENSO)(ENSO)

Current Status and ForecastCurrent Status and Forecast ENSO-neutral (average) ENSO-neutral (average) conditions continue conditions continue across the equatorial Pacific Ocean, but across the equatorial Pacific Ocean, but significant warming of sea-surface temperatures significant warming of sea-surface temperatures (SSTs) is occurring across the tropical Pacific (SSTs) is occurring across the tropical Pacific Ocean. SSTs are now above average.Ocean. SSTs are now above average. The Climate Prediction Center (CPC) is The Climate Prediction Center (CPC) is forecasting the development of forecasting the development of El Niño (warm El Niño (warm conditions)conditions) this summer.this summer. The “analog years” used in this forecast The “analog years” used in this forecast support the development of a “moderate support the development of a “moderate strength” strength” El NiñoEl Niño this coming autumn and this coming autumn and winter.winter.http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-w

eb.pdf

Tropical Pacific OceanTropical Pacific OceanAnimated Animated (in PowerPoint only) (in PowerPoint only) SSTs (top) / Anomalies SSTs (top) / Anomalies

(bottom)(bottom)

Courtesy: Courtesy: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstanim.shtml

Tropical Pacific OceanTropical Pacific Ocean SSTs have warmed to above average, mainly west SSTs have warmed to above average, mainly west

and eastand east

Courtesy: Courtesy: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstweek_c.gif

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

J F M A M J J A S O N D J F M A M J J A S O N D

SO

I

Month

SOI* values from the top "analog years" compared with the current period (2013-14)

2013-14

2008-09

1967-68

1962-63

*For SOI explanation see: http://oregon.gov/ODA/NRD/docs/pdf/forecast_method.pdf

ENSO IndicesENSO Indices

El El NiñoNiño

La La NiñaNiña

(2008-09; 1967-68; 1962-63)

ENSO-Neutral

La Niña La Niña conditions developed, during the winter, in 1 of the top 3 analog years.

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

ON

I

3-Month Running Mean

ONI* values from the top "analog years"compared with the current period (2013-14)

2013-14

2008-09

1967-68

1962-63

*For ONI explanation see: http://oregon.gov/ODA/NRD/docs/pdf/forecast_method.pdf

El Niño El Niño conditions developed, by the subsequent autumn, in each of the top 3 analog years.

La La NiñaNiña

El El NiñoNiño

ENSO IndicesENSO Indices

(2008-09; 1967-68; 1962-63)

ENSO-Neutral

Model forecasts favor ENSO-neutral conditions through spring 2014; followed byEl Niño development.

ENSO Predictive ModelsENSO Predictive Models Computer models favor El Niño development this Computer models favor El Niño development this

summersummer

Courtesy: Courtesy: http://iri.columbia.edu/climate/ENSO/currentinfo/SST_table.html

La La NiñaNiña

El El NiñoNiño

ENSO-neutral

June 2014 ForecastJune 2014 ForecastTemperatures Precipitation

No significant departures from average temperatures No significant departures from average temperatures were indicated by the top analog years.were indicated by the top analog years.

Rainfall slightly below average west and slightly Rainfall slightly below average west and slightly above average east.above average east.

July 2014 ForecastJuly 2014 ForecastTemperatures Precipitation

Wide ranging temperatures during analog years Wide ranging temperatures during analog years lowers forecast confidence. Extremes in either lowers forecast confidence. Extremes in either direction are possible.direction are possible.

Drier than average conditions likely. Since July is Drier than average conditions likely. Since July is typically a “dry” month, large negative precipitation typically a “dry” month, large negative precipitation departures are not possible. departures are not possible.

August 2014 ForecastAugust 2014 ForecastTemperatures Precipitation

Once again, the analog years had enough variation of Once again, the analog years had enough variation of weather conditions to significantly lower forecast weather conditions to significantly lower forecast confidence.confidence.

Temperatures favoring slightly cooler than average. Temperatures favoring slightly cooler than average. Near to above average precipitation likely.Near to above average precipitation likely.

June – August 2014 ForecastJune – August 2014 ForecastTemperatures Precipitation

A slight tendency for a cooler and wetter than A slight tendency for a cooler and wetter than average August skews the 3-month temperature and average August skews the 3-month temperature and precipitation forecast graphics to cool and damp, but precipitation forecast graphics to cool and damp, but forecast confidence is low. forecast confidence is low.

There is no clear signal, in either direction, from There is no clear signal, in either direction, from average conditions.average conditions.

Some Helpful ResourcesSome Helpful Resources CPC Official US Three-Month Forecasts CPC Official US Three-Month Forecasts (Graphics):(Graphics):http://www.cpc.ncep.noaa.gov/products/predictions/long_range/seasonal.php?lead=01

CPC US 30-Day & 90-Day Forecasts (Discussions):CPC US 30-Day & 90-Day Forecasts (Discussions):http://www.cpc.ncep.noaa.gov/products/predictions/long_range/fxus07.htmlhttp://www.cpc.ncep.noaa.gov/products/predictions/long_range/fxus07.html

CPC Weekly & Monthly ENSO Discussions: CPC Weekly & Monthly ENSO Discussions: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisoryhttp://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory

Australian Government Weekly Tropical Climate Australian Government Weekly Tropical Climate Note:Note:http://www.bom.gov.au/climate/tropnote/tropnote.shtmlhttp://www.bom.gov.au/climate/tropnote/tropnote.shtml

Australian Government ENSO Wrap-Up:Australian Government ENSO Wrap-Up:http://www.bom.gov.au/climate/ensohttp://www.bom.gov.au/climate/enso

IRI ENSO Quick Look:IRI ENSO Quick Look:http://portal.iri.columbia.edu/portal/server.pt?open=512&objID=945&mode=2http://portal.iri.columbia.edu/portal/server.pt?open=512&objID=945&mode=2

NRCS Western Snowpack Data & Water Supply NRCS Western Snowpack Data & Water Supply Forecast:Forecast:http://www.wcc.nrcs.usda.gov/cgibin/westsnowsummary.plhttp://www.wcc.nrcs.usda.gov/cgibin/westsnowsummary.pl

Updated MonthlyUpdated Monthly(around the 20(around the 20thth))

Contact: Pete Parsons, ODF Meteorologist503-945-7448 [email protected]

ODA Production support from Diana Walker and Andy Zimmerman

Contact: Pete Parsons, ODF Meteorologist503-945-7448 [email protected]

ODA Production support from Diana Walker and Andy Zimmerman

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