FRCC Seasonal Transmission Assessment & Operational Seasonal Study Winter 2012.
Seasonal Climate Forecast Dec. 2012 – Feb. 2013 (Issued: November 15, 2012) This Product is...
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Seasonal Climate Seasonal Climate Forecast Forecast Dec. 2012 – Feb. 2013 Dec. 2012 – Feb. 2013 (Issued: November 15, 2012) (Issued: November 15, 2012) This Product is Published by the Oregon This Product is Published by the Oregon Department of Agriculture (ODA), in Department of Agriculture (ODA), in Cooperation Cooperation with the Oregon Department of Forestry with the Oregon Department of Forestry (ODF). (ODF). Contact: ODF Meteorologist Pete Parsons Contact: ODF Meteorologist Pete Parsons at 503-945-7448 [email protected] at 503-945-7448 [email protected]
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Transcript of Seasonal Climate Forecast Dec. 2012 – Feb. 2013 (Issued: November 15, 2012) This Product is...
Seasonal Climate Seasonal Climate ForecastForecast
Dec. 2012 – Feb. 2013Dec. 2012 – Feb. 2013(Issued: November 15, 2012)(Issued: November 15, 2012)
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.aspxhttp://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.aspxhttp://cms.oregon.gov/ODA/NRD/Pages/weather.aspx
El Niño Southern Oscillation El Niño Southern Oscillation (ENSO)(ENSO)
ENSO-neutral (near normal) ENSO-neutral (near normal) conditions are conditions are continuing. However, central and western tropical continuing. However, central and western tropical Pacific Ocean sea-surface temperatures (SSTs) Pacific Ocean sea-surface temperatures (SSTs) remain above normal.remain above normal. A full-fledged A full-fledged weak El Niño eventweak El Niño event is becoming less is becoming less likely this winter, with the most recent trends in the likely this winter, with the most recent trends in the opposite direction (towards ENSO-neutral opposite direction (towards ENSO-neutral conditions).conditions).The previously issued The previously issued “El Niño Watch” “El Niño Watch” has been has been discontinued by the Climate Prediction Center discontinued by the Climate Prediction Center (CPC).(CPC). The official CPC forecast is now for ENSO-neutral The official CPC forecast is now for ENSO-neutral conditionsconditions to continue through this winter.to continue through this winter.
Courtesy: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisoryCourtesy: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisoryhttp://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/
ensodisc.htmlensodisc.html
Tropical Pacific OceanTropical Pacific OceanAnimated Animated (in PowerPoint only) (in PowerPoint only) SSTs (top) / Anomalies SSTs (top) / Anomalies
(bottom)(bottom)
Courtesy: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstanim.shtmlCourtesy: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstanim.shtml
Tropical Pacific OceanTropical Pacific Ocean “ENSO Neutral” “ENSO Neutral” conditions are continuing…conditions are continuing…
Courtesy: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstweek_c.gifCourtesy: 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 For the Top "Analog Years"and the Current Year (2011-12)
2011-12
2008-09
2000-01
1950-51
*ForSOI explanation see: http://oregon.gov/ODA/NRD/docs/pdf/forecast_method.pdf
ENSO IndicesENSO Indices
El El NiñoNiño
La La NiñaNiña
(2008-09; 2000-01; 1950-51)
-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 For the Top "Analog Years"and the Current Year (2011-12)
2011-12
2008-09
2000-01
1950-51
*ForONI explanation see: http://oregon.gov/ODA/NRD/docs/pdf/forecast_method.pdf
ENSO IndicesENSO Indices
El El NiñoNiño
La La NiñaNiña
(2008-09; 2000-01; 1950-51)
ENSO Predictive ModelsENSO Predictive Models Most models predict continued slow cooling in the central Most models predict continued slow cooling in the central
tropical Pacific Ocean tropical Pacific Ocean
Courtesy: http://iri.columbia.edu/climate/ENSO/currentinfo/SST_table.htmlCourtesy: http://iri.columbia.edu/climate/ENSO/currentinfo/SST_table.html
La La NiñaNiña
El El NiñoNiño
ENSO-neutral conditions aremost likely through mid-2013
ENSO Predictive ModelsENSO Predictive ModelsThe CPC/IRI consensus forecastThe CPC/IRI consensus forecast
Courtesy: http://portal.iri.columbia.edu/portal/server.pt?open=512&objID=945&mode=2Courtesy: http://portal.iri.columbia.edu/portal/server.pt?open=512&objID=945&mode=2
ENSO-neutral conditions aremost likely through mid-2013
December 2012 ForecastDecember 2012 ForecastTemperatures Precipitation
Stormy periods likely. Cooler than normal with near to Stormy periods likely. Cooler than normal with near to above normal precipitation. Increased chance of Arctic above normal precipitation. Increased chance of Arctic outbreaks late in the month.outbreaks late in the month.
Diverse weather during the analog years (some mild Diverse weather during the analog years (some mild and stormy and others with significant cold episodes) and stormy and others with significant cold episodes) lowers forecast confidence.lowers forecast confidence.
January 2013 ForecastJanuary 2013 ForecastTemperatures Precipitation
ENSO-neutral conditions favor stormy and mild ENSO-neutral conditions favor stormy and mild periods alternating with cold and dry stretches (often periods alternating with cold and dry stretches (often with Arctic outbreaks and valley snow).with Arctic outbreaks and valley snow).
Overall temperatures will depend on the severity of Overall temperatures will depend on the severity of any cold snaps.any cold snaps.
Diverse weather during the analog years lowers Diverse weather during the analog years lowers forecast confidence.forecast confidence.
February 2013 ForecastFebruary 2013 ForecastTemperatures Precipitation
Seasonal temperatures with below normal Seasonal temperatures with below normal precipitation.precipitation.
Most analog years had El Niño episodes, which would Most analog years had El Niño episodes, which would typically yield a mild and dry February. However, typically yield a mild and dry February. However, ENSO-neutral conditions are likely this year, so ENSO-neutral conditions are likely this year, so precipitation totals may be closer to normal than precipitation totals may be closer to normal than indicated.indicated.
Dec. 2012 – Feb. 2013 Dec. 2012 – Feb. 2013 ForecastForecast
Temperatures Precipitation
Mild and stormy periods alternating with cool and Mild and stormy periods alternating with cool and drier periods. Severity of any cold snaps will strongly drier periods. Severity of any cold snaps will strongly influence overall departures.influence overall departures.
ENSO-neutral conditions favor Arctic intrusions and ENSO-neutral conditions favor Arctic intrusions and valley snow events, mainly from mid-December valley snow events, mainly from mid-December through January.through January.
Winter 2012-13 Winter 2012-13 HighlightsHighlights
There are no excellent analog matches for There are no excellent analog matches for this winter (looking back over the past 100+ this winter (looking back over the past 100+ years).years).
It is rare to have back-to-back La Niña It is rare to have back-to-back La Niña winters (the past two) followed by ENSO-winters (the past two) followed by ENSO-neutral conditions (forecast for this winter). neutral conditions (forecast for this winter). This year is also unique due to the recent This year is also unique due to the recent decay of what appeared to be a developing decay of what appeared to be a developing El Niño episode.El Niño episode.
ENSO-neutral winters tend to produce ENSO-neutral winters tend to produce stormy and mild periods alternating with stormy and mild periods alternating with cool and dry periods (often Arctic cool and dry periods (often Arctic outbreaks). The transitions can bring valley outbreaks). The transitions can bring valley snow & ice.snow & ice.
The favored ENSO-neutral period for Arctic The favored ENSO-neutral period for Arctic outbreaks and valley snow events is from outbreaks and valley snow events is from mid-December through January.mid-December through January.
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 Mary Jane Schaffer
Contact: Pete Parsons, ODF Meteorologist503-945-7448 [email protected]
ODA Production support from Diana Walker and Mary Jane Schaffer
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