ALASKA REGION CLIMATE OUTLOOK BRIEFING November 16, 2018 Rick Thoman Alaska Center for Climate Assessment and Policy
Today s Outline Feature of the month: Southeast Drought Update Climate Forecast Basics Climate System Review CPC Forecasts and observations for most recent month and season Current Atmosphere and Ice Climate Drivers: SSTs, ENSO Climate Forecast Guidance ENSO Statistical Dynamic NMME & C3S CPC Outlooks December and Dec-Feb 2018-19 First look ahead at Spring 2019
Current Southeast Drought Status Moderate to severe drought continues Primary impact to hydropower production Drought Monitor November 06, 2018 D0 D2 D1
Measures of Southeast Drought 1 st half of November rainfall has been near normal
Climate Forecast Basics Climate Prediction Center: primary NOAA/NWS forecast responsibility Climate Outlooks Relation to some long term normal (e.g. 1981-2010) Categorical (often three) Probabilistic Traditional Elements Temperature: centered around average Precipitation: centered around median (can significantly differ from the normal, which by convention is the mean) Chances of this box? Chances of this box? Chances of this box?
Warmest October of record (exceeded 2013) Incredibly late first freeze Very low snow much of mainland
October 2018 Temperature Anomalies Non-EC Skill Score: +100 Mid-Month Outlook Best possible: +100 No skill: 0 Worst possible: -50 Above Normal Near Normal Below Normal Preliminary NOAA/NWS data subject to revision
October 2018 Precipitation Anomalies Non-EC Skill Score: +29 Mid-Month Outlook Best possible: +100 No skill: 0 Worst possible: -50 Above Normal Near Normal Below Normal Preliminary NOAA/NWS data subject to revision
Aug-Sep-Oct 2018 Temperature Anomalies Non-EC Skill Score: +91 Best possible: +100 No skill: 0 Worst possible: -50 Above Normal Near Normal Below Normal Preliminary NOAA/NWS data subject to revision
Aug-Sep-Oct 2018 Precipitation Anomalies Non-EC Skill Score: +39 Best possible: +100 No skill: 0 Worst possible: -50 Above Normal Near Normal Below Normal Preliminary NOAA/NWS data subject to revision
Current SST Departures from Normal From OI SSTv2 Data Source: NOAA/PSD/ESRL
Arctic Wide Sea Ice Through November 14, 2018 Red Line: 2016 Blue line: 2017 Orange line: 2018
Arctic Sea Ice Volume & Thickness End of October Arctic sea ice volume: typical for past 10 years End of October thickness: below normal most everywhere PIOMAS/U. a Sources: Data from U. Wa./PIOMAS data Graphics by Z. Labe, UC Irvine
Mid-November Sea Ice Comparison November 14, 2018 November 14, 2017
Sea Ice Near Alaska
Global SST Anomalies Sept PDO: +0.09 Mostly above normal equatorial Pacific
Upper Ocean Heat Content Anomaly Heat Content Anomaly ( C) in the upper 300m Source: CPC
Tropical Pacific
Tropical Pacific SSTs & Atmosphere More convection Less convection OISSTv2 Weekly 1981-2010 climo Trade winds near normal
Time Equatorial Upper Ocean Heat Anomaly Oceanic Kelvin Waves
Guidance ENSO Models Expert Evaluation Statistical Trends in the Past 15 Years Correlations SST Anomalies Oceanic Correlation (PDO) Dynamic SST Anomalies Global Temp and Pcpn Anomalies
NMME Niño 3.4 Forecasts Strong consensus for El Niño winter, decreasing spring/summer
CPC Niño 3.4 Forecasts: Experts ENSO Alert System Status: El Niño Watch Outlook only slightly little changed: El Niño likely for winter
2003-2017 Trends December Compared to 1981-2010 00-33=Below normal 34-66=Near normal 67-100=Above normal Temps Dec-Feb Pcpn
Constructed Analogs based on Global SSTs Temperature Outlook Precipitation Outlook
Past El Niño Winters
Dynamic Model Forecasts Extratropical SSTs Alaska regional Sea Ice Temp and Pcpn Anomalies
NMME Dec-Feb 2018-19 SST Departures from Normal Forecast Skill High skill Not much of a PDO pattern
Sea Ice Autumn Freeze-up Outlook
December 2018 Temp Anomaly Outlooks Avg Dep ( C) 3-Category Probabilities Calibrated 3-Category Probs Member Averages
December 2018 Pcpn Anomaly Outlooks Avg Dep (mm/day) 3-Category Probabilities Calibrated 3-Category Probs Member Averages
Calibrated Probability Forecasts for December 2018 Forecast from: September October November
Dec-Jan-Feb 2018-19 Temp Anomaly Forecasts Avg Dep ( C) Category Probs Calibrated Category Probs Member Averages
Dec-Jan-Feb 2018-19 Pcpn Anomaly Forecasts Avg Dep (mm/day) Category Probs Calibrated Category Probs Member Averages
Calibrated Probability Forecasts for Dec-Jan-Feb 2018-19 Forecast from: July August September
NMME Skill for December & Dec-Jan-Feb Temp Pcpn
C3S Multi-Model Ensemble for DJF 2018-19 Average Temperature Category Probabilities Total Precipitation
October s Dec-Feb 2018-19 Outlook 45% 22% 37% 30% 55% 12% 45% 22% Above% Normal% Below%
And the Answer Is
CPC December 2018 Outlook 75% 22% 03% 37% 30% 37% 30% 65% 30% 05% 45% 22% 55% 12% Above% Normal% Below%
CPC Dec-Jan-Feb 2018-19 Outlook 45% 22% 55% 12% 65% 30% 05% 45% 22% 37% 30% 45% 22% Above% Normal% Below%
Look Ahead: Spring 2019 45% 22% 55% 12% Above% Normal% Below%
Climate Links ACCAP Climate and Weather Highlights https://accap.uaf.edu/tools/climate_highlights#date/ CPC Monthly http://www.cpc.ncep.noaa.gov/products/predictions/30day/ CPC Seasonal http://www.cpc.ncep.noaa.gov/products/predictions/90day/ ENSO at CPC (including weekly briefing) http://www.cpc.ncep.noaa.gov/products/precip/cwlink/mjo/enso.sh tml ENSO at IRI http://iri.columbia.edu/our-expertise/climate/forecasts/enso/