150 likes | 420 Views
Seasonal Climate Forecast March – May 2014 (Issued: February 20, 2014). This Product is Published by the Oregon Department of Agriculture (ODA), in Cooperation with the Oregon Department of Forestry (ODF). Contact: ODF Meteorologist Pete Parsons at 503-945-7448 pparsons@odf.state.or.us
E N D
Seasonal Climate ForecastMarch – May 2014(Issued: February 20, 2014) This Product is Published by the Oregon Department of Agriculture (ODA), in Cooperation with the Oregon Department of Forestry (ODF). Contact: ODF Meteorologist Pete Parsons at 503-945-7448 pparsons@odf.state.or.us Get related Seasonal Climate Forecast information at http://cms.oregon.gov/ODA/NRD/Pages/weather.aspx
Forecast Method Notes… • The analog years were obtained by tracking and comparing a variety of indices over the past several years (see Forecasting Methods). • Years in the “Cool Phase” of the Pacific Decadal Oscillation (PDO) were given highest priority. • The 1961 analog year was dropped this month in favor of 1963. 1962 and 1968 remain the other top years. • All three years were “weighted” equally to create the forecast graphics, but 1963 and 1968 appear to match up best with current conditions.
El Niño Southern Oscillation (ENSO)Current Status and Forecast • ENSO-neutral (average) conditions are present across the equatorial Pacific Ocean. • Sea-surface temperatures (SSTs) are below average across sections of the central and eastern equatorial Pacific Ocean (into La Niña territory). • The Climate Prediction Center (CPC) and most computer models predict ENSO-neutral persisting through spring 2014; with possible El Niño conditions developing this summer. http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf
Tropical Pacific OceanAnimated (in PowerPoint only) SSTs (top) / Anomalies (bottom) Courtesy: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstanim.shtml
Tropical Pacific OceanTemperatures have cooled to below average central and east Courtesy: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstweek_c.gif
ENSO Indices (1961-62;1962-63; 1967-68) La Niña Neutral El Niño
ENSO Indices (1961-62;1962-63; 1967-68) El Niño conditions developed, during the subsequent autumn, in 2 of the top 3 analog years. El Niño Neutral La Niña conditions developed, during the winter, in 1 of the top 3 analog years. La Niña
ENSO Predictive ModelsComputer models predict ENSO-neutral through spring 2014 El Niño Model forecasts favor ENSO-neutral conditions through spring 2014; followed by possible El Niño development. ENSO-neutral La Niña Courtesy: http://iri.columbia.edu/climate/ENSO/currentinfo/SST_table.html
March 2014 Forecast Temperatures Precipitation • Analog years had a wide range in both temperatures and precipitation, which significantly lowers forecast confidence. • Mountain snowpacks likely peaking well below average.
April 2014 Forecast Temperatures Precipitation • Temperatures likely near or below normal. • Elevated chances for late-season freezing temperatures in the west. • Cool temperatures and continued mountain snow may locally extend the peak of, below normal, mountain snowpacks well into April.
May 2014 Forecast Temperatures Precipitation • Top analog years all had below average temperatures, especially early, which would delay mountain snow-melt and maintain soil moisture. • However, near to slightly above normal precipitation will not likely make up for pre-existing drought conditions and snowpack deficits.
March – May 2014 Forecast Temperatures Precipitation • Cooler than average temperatures are likely, which would delay the peak and melt-off of, significantly below average, mountain snowpacks. • Precipitation most likely near average; ranging from slightly above average in the NW to slightly below average in the SW and east.
Resources • CPC Official US Three-Month Forecasts (Graphics): http://www.cpc.ncep.noaa.gov/products/predictions/long_range/seasonal.php?lead=01 • CPC US 30-Day & 90-Day Forecasts (Discussions): http://www.cpc.ncep.noaa.gov/products/predictions/long_range/fxus07.html • CPC Weekly & Monthly ENSO Discussions: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory • Australian Government Weekly Tropical Climate Note: http://www.bom.gov.au/climate/tropnote/tropnote.shtml • Australian Government ENSO Wrap-Up: http://www.bom.gov.au/climate/enso • IRI ENSO Quick Look: http://portal.iri.columbia.edu/portal/server.pt?open=512&objID=945&mode=2 • NRCS Western Snowpack Data & Water Supply Forecast: http://www.wcc.nrcs.usda.gov/cgibin/westsnowsummary.pl
Updated Monthly(around the 20th) Your Feedback is Welcome Contact: Pete Parsons, ODF Meteorologist 503-945-7448 pparsons@odf.state.or.us ODA Production support from Diana Walker and Andy Zimmerman