ALASKA REGION CLIMATE OUTLOOK BRIEFING June 22, 2018 Rick Thoman National Weather Service Alaska Region
Today s Outline Feature of the month: Ocean Warmth Headed into Summer Climate Forecast Basics Climate System Review CPC Forecasts and observations for most recent month and season Current Atmosphere and Ice Climate Drivers: SSTs, PDO, ENSO Climate Forecast Guidance ENSO Statistical Dynamic NMME & C3S CPC Outlooks July and July-September 2018 Look at Autumn 2018
Alaska regional oceans mostly warm
SST Changes through Time Trend lines are best linear fit
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?
May 2018 Temperature Anomalies Non-EC Skill Score: -18 Mid-Month Outlook Above normal Near Normal Below Normal Preliminary data subject to revision
May 2018 Precipitation Anomalies Non-EC Skill Score: +33 Mid-Month Outlook Above normal Near Normal Below Normal Preliminary data subject to revision
Mar-Apr-May 2018 Temperature Anomalies Non-EC Skill Score: +59 Above normal Near Normal Below Normal Preliminary data subject to revision
Mar-Apr-May 2018 Precipitation Anomalies Non-EC Skill Score: +12 Above normal Near Normal Below Normal Preliminary data subject to revision
Arctic Wide Sea Ice Through June 20, 2018 Red Line: 2016 Blue line: 2017 Orange line: 2018
Arctic Sea Ice Volume & Thickness End of May Arctic sea ice volume: fourth lowest in satellite era (since 1979) End of May thickness above normal Laptev Sea, below elsewhere PIOMAS/U. a Sources: Data from U. Wa./PIOMAS data Graphics by Z. Labe, UC Irvine
Mid-June Sea Ice Comparison June 20, 2018 June 20, 2017
Sea Ice Near Alaska
Alaska Near-Shore SSTs
Global SST Anomalies Not a PDO Pattern Near to above normal equatorial Pacific except near South America
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
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
CPC Niño 3.4 Forecasts: Models Neutral through summer, increasing consensus for El Niño autumn/winter
CPC Niño 3.4 Forecasts: Experts ENSO Alert System Status: El Niño Watch ENSO neutral favored through summer El Niño more likely than not for autumn/winter
2003-2017 Trends July Compared to 1981-2010 00-33=Below normal 34-66=Near normal 67-100=Above normal Temps Jul-Sep Precip
Constructed Analogs based on Global SSTs
PDO Correlations: Jul-Aug-Sep observed vs. Apr-May-Jun PDO 1989-2017 Temperature 1989-2017 Precipitation
Dynamic Model Forecasts Extratropical SSTs Alaska regional Sea Ice Temp and Pcpn Anomalies
NMME Jul-Sep 2018 SST Departures from Normal Forecast Skill Not much of a PDO pattern
Sea Ice Spring Meltout Outlook CPC Experimental Forecast
Change in Forecast Melt-out from April Outlook
July 2018 Temp Anomaly Outlooks Avg Dep ( C) 3-Category Probabilities Calibrated 3-Category Probs Member Averages
July 2018 Pcpn Anomaly Outlooks Avg Dep (mm/day) Member Averages 3-Category Probabilities Calibrated 3-Category Probs
Calibrated Probability Forecasts for July 2018 Forecast from: April May June
Jul-Aug-Sep 2018 Temp Anomaly Forecasts Avg Dep ( C) Category Probs Calibrated Category Probs Member Averages
Jul-Aug-Sep 2018 Pcpn Anomaly Forecasts Avg Dep (mm/day) Member Averages Category Probs Calibrated Category Probs
Calibrated Probability Forecasts for Jul-Aug-Sep 2018 Forecast from: April May June
NMME Skill for July & Jul-Aug-Sep Temp Pcpn
C3S Multi-Model Ensemble for JAS 2018 Average Temperature Category Probabilities Total Precipitation
Jul-Aug-Sep 2018 Outlook from May
And the Answer Is
CPC July 2018 Outlook 55% 12% 45% 22% 45% 22% 37% 30% 37% Above% Normal% Below% 45% 22% 30%
CPC Jul-Aug-Sep 2018 Outlook 55% 12% 45% 22% 45% 65% 30% 05% 22% 37% 30% Above% Normal% Below%
Look Ahead: Fall 2018 55% 12% 65% 30% 05% 45% 22% 45% 22% 37% 30% Above% Normal% Below%
Climate Forecast Links CPC Monthly http://www.cpc.ncep.noaa.gov/products/predictions/30day/ CPC Seasonal http://www.cpc.ncep.noaa.gov/products/predictions/90day/ NMME http://www.cpc.ncep.noaa.gov/products/nmme/ ENSO at CPC (including weekly briefing) http://www.cpc.ncep.noaa.gov/products/precip/cwlink/mjo/ enso.shtml ENSO at IRI http://iri.columbia.edu/our-expertise/climate/forecasts/enso/