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Seasonal Climate Forecast Verification February – April 2014 (Issued: May 21, 2014). Note: This product is published by the Oregon Department of Agriculture (ODA), in cooperation with the Oregon Department of Forestry (ODF). Contact: Pete Parsons, ODF Meteorologist
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Seasonal Climate ForecastVerificationFebruary – April 2014(Issued: May 21, 2014) Note: This product is published by the Oregon Department of Agriculture (ODA), in cooperation with the Oregon Department of Forestry (ODF). Contact: Pete Parsons, ODF Meteorologist 503-945-7448 pparsons@odf.state.or.us ODA Production support from Diana Walker and Andy Zimmerman
Format and Purpose: • A side-by-side comparison of the “Seasonal Climate Forecast” vs. what (Actually Occurred) is done for both the 1-month & 3-month forecasts. • To assess the utility of this forecast and form a basis for adjustments to the forecast method*. • Note: 1981-2010 long-term averages are used. * See “Forecasting Methods…” at: http://cms.oregon.gov/ODA/NRD/pages/weather.aspx
Verification Updates: • This forecast method verifies best during El Niño (warm) or La Niña (cold) events. ENSO-neutral winters are more varied and usually have more “extreme” weather events. • A return to the “cool phase” of the Pacific Decadal Oscillation (PDO), which occurred no later than 2007, appears to be significantly influencing Oregon’s weather. • Using analog years from other “cool phase” periods should help to limit forecast error. However, most of those years are prior to 1977, which adds another element of error (adjustments are not made for any large-scale changes in climate between then and now).
February 2014(Forecast Issued January 28, 2014) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)
February 2014(Forecast Issued January 28, 2014) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)
February 2014(Forecast Issued January 28, 2014)/(Actual) • Temperatures in top analog years ranged from near normal (1962) to record warm (1968). (Below average temperatures across the northern zones, mainly due to an “extreme” cold spell early in the month. Southern zones were warmer than average.) • Near to above normal precipitation will not make up for well below normal existing mountain snowpack deficits).(Precipitation was above to well above average. Mountain snowpacks showed some improvement but remained well below average.)
March 2014(Forecast Issued February 20, 2014) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)
March 2014(Forecast Issued February 20, 2014) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)
March 2014(Forecast Issued February 20, 2014)/(Actual) • Below average temperatures. (Temperatures were above average. A colder than average 1962 analog year led the forecast astray. That year was replaced with 1957 in subsequent forecasts.) • Precipitation near average…ranging from slightly above average NW to slightly below average SW and east. (Precipitation ranged from well above average west to slightly above average east. Mountain snowpacks increased, relative to average; ranging from slightly below average extreme north to well below average south.)
April 2014(Forecast Issued March 20, 2014) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)
April 2014(Forecast Issued March 20, 2014) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)
April 2014(Forecast Issued March 20, 2014)/(Actual) • Below average temperatures likely. (Temperatures were warmer than average statewide.) • Near to below normal precipitation. (Precipitation was generally near to slightly below normal.)
February – April 2014(Forecast Issued January 28, 2014) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)
February – April 2014(Forecast Issued January 28, 2014) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)
February – April 2014(Forecast Issued January 28, 2014)/(Actual) • Near average temperatures. (Temperatures were generally below average in February and above average in March and April…near to slightly above average overall.) • Above average precipitation; dependent on a wet February and early March…with above average mountain snowfall. (After a dry January, February and March turned wet, including a major snowstorm for western Oregon in early February. Above average mountain snowfall generally did not compensate for large existing winter snowpack deficits.)
Updated Monthly(Around the 20th) Your Feedback is Welcome! Pete Parsons, ODF Meteorologist 503-945-7448 pparsons@odf.state.or.us