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Seasonal Climate Forecast Verification Dec. 2013 – Feb. 2014 (Issued: March 20, 2014)

Seasonal Climate Forecast Verification Dec. 2013 – Feb. 2014 (Issued: March 20, 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 Forecast Verification Dec. 2013 – Feb. 2014 (Issued: March 20, 2014)

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  1. Seasonal Climate ForecastVerificationDec. 2013 – Feb. 2014(Issued: March 20, 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

  2. 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

  3. 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).

  4. December 2013(Forecast Issued November 20, 2013) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)

  5. December 2013(Forecast Issued November 20, 2013) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)

  6. December 2013(Forecast Issued November 20, 2013)/(Actual) • Temperature forecast uncertain, but “extreme” weather and above normal precipitation likely. (We certainly had some “extreme” weather! An Arctic cold snap gripped most of the state from the 3rd through the 12th. Several inches of snow blanketed the central and southern Willamette Valley. The coldest morning was the 8th, when Eugene dropped to -10° F…their second coldest minimum temperature on record for any date. Burns fell to -30° F and Lakeview hit -27° F …both all-time record low temperatures for any date! Precipitation was below to well below normal.)

  7. January 2014(Forecast Issued December 30, 2013) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)

  8. January 2014(Forecast Issued December 30, 2013) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)

  9. January 2014(Forecast Issued December 30, 2013)/(Actual) • Top analog years were all colder than average. (A persistent upper-level ridge resulted in generally above normal temperatures, especially in the mountains. Cool air trapped at lower elevations made for stagnant conditions in valleys and river basins.) • Near normal precipitation is most likely, but “extremes” are possible. (Precipitation was “extremely” below average statewide, with a general lack of storm activity. Mountain snowpacks were only 20-50% of average across most of the state, by month’s end, with extreme NE Oregon at 70-80% of average.)

  10. February 2014(Forecast Issued January 28, 2014) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)

  11. February 2014(Forecast Issued January 28, 2014) Forecast Precipitation Actual Precipitation Data courtesy of the National Climatic Data Center (NCDC)

  12. 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.)

  13. Dec. 2013 – Feb. 2014(Forecast Issued November 20, 2013) Forecast Temperatures Actual Temperatures Data courtesy of the National Climatic Data Center (NCDC)

  14. Dec. 2013 – Feb. 2014(Forecast Issued November 20, 2013) Forecast Precipitation Actual Precipitation August 2013 - Data courtesy of the National Climatic Data Center (NCDC)

  15. Dec. 2013 – Feb. 2014(Forecast Issued November 20, 2013)/(Actual) • Cooler and wetter than average, with episodes of “extreme” weather likely. (“Extreme” cold in early to mid December. A persistent upper-level ridge brought mild conditions in January. Another “extreme” cold and snowy period in early February.) • At least one significant low-elevation snow episode in Western Oregon. Average or above average mountain snowfall. (Two major cold and snow episodes hit western Oregon; early-to-mid December and early February. Precipitation, including mountain snowfall, was well below average.)

  16. Updated Monthly(Around the 20th) Your Feedback is Welcome! Pete Parsons, ODF Meteorologist 503-945-7448 pparsons@odf.state.or.us

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