Seasonal Climate Forecast May July 2013 Verification (Issued: August 15, 2013) 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 Sean Fornelli
Format and Purpose: n A side-by-side comparison of the Seasonal Climate Forecast vs. what (Actually Occurred) is done for both 1-month & 3-month periods. n To assess the utility of this forecast and form a basis for adjustments to the forecast method*. n Note: Now using (1981-2010) long-term averages. * See Forecasting Methods at: http://cms.oregon.gov/oda/nrd/pages/weather.aspx
Verification Updates: n Climate trends appear to be more evident during El Niño (warm) or La Niña (cold) events. n Forecasts for 3-month (longer) periods generally outperform 1-month (shorter) period forecasts. n The switch back to the cool phase of the Pacific Decadal Oscillation (PDO), which occurred no later than 2007, appears to be having a significant influence on Oregon s climate (mostly towards cooler and wetter conditions). n Note: Using (1981-2010) long-term averages.
May 2013 (Forecast Issued April 23, 2013) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)
May 2013 (Forecast Issued April 23, 2013) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)
May 2013 (Forecast Issued April 23, 2013)/(Actual) n Temperatures slightly cooler than average, mainly west. (A very warm and dry first half of the month was countered by a cool and damp second half of the month. Although overall temperatures were above normal statewide, most locations had a roughly equal number of days with above and below normal temperatures.) n Precipitation below average west; near average east. (A very dry first half of the month was compensated for by damp latter half of the month, especially along the coast and in the Willamette valley.)
June 2013 (Forecast Issued May 22, 2013) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)
June 2013 (Forecast Issued May 22, 2013) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)
June 2013 (Forecast Issued May 22, 2013)/(Actual) n Near average temperatures and near to slightly below average precipitation. (Temperatures were above average statewide, especially from the Cascades westward. Precipitation was mostly near average; slightly below west and above east.) n At least one (1) 90 + F day likely in the Willamette Valley. (The month began and ended with warm spells closing with three (3) consecutive 90 + F days in the Willamette Valley.)
July 2013 (Forecast Issued June 18, 2013) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)
July 2013 (Forecast Issued June 18, 2013) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)
July 2013 (Forecast Issued June 18, 2013)/(Actual) n Above average temperatures likely, especially for eastern zones. (With the exception of slightly cooler than average weather along the coast, temperatures were warmer than average statewide, especially in SW, central, and eastern Oregon.) n Typically dry statewide. (Precipitation was below normal statewide, with many areas receiving little or no rain.)
May July 2013 (Forecast Issued April 23, 2013) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)
May July 2013 (Forecast Issued April 23, 2013) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)
May July 2013 (Forecast Issued April 23, 2013)/(Actual) n Near to slightly below normal temperatures. (Above normal temperatures statewide.) n Below normal precipitation, especially east of the Cascades. (Slightly above normal precipitation along the coast and in northcentral Oregon. Below normal precipitation across the remainder of the state.) n Possible early start to fire season, especially south and east. (In late July, lightning started multiple large fires across SW Oregon.)
Updated Monthly (mid-month) Your Feedback is Welcome! Pete Parsons, ODF Meteorologist 503-945-7448 pparsons@odf.state.or.us