ALASKA REGION CLIMATE OUTLOOK BRIEFING July 20, 2018 Rick Thoman National Weather Service Alaska Region
Today s Outline Feature of the month: 2018 Wildfire Season 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 August and Aug-Oct 2018 Look at Autumn 2018
2018 Wildfire Season So Far
2018 Wildfire Season in Context
The rest of the wildfire season?
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?
June 2018 Temperature Anomalies Non-EC Skill Score: +09 Best possible: +100 No skill: 0 Worst possible: -50 Mid-Month Outlook Above normal Near Normal Below Normal Preliminary data subject to revision
June 2018 Precipitation Anomalies Non-EC Skill Score: +14 Best possible: +100 No skill: 0 Worst possible: -50 Mid-Month Outlook Above normal Near Normal Below Normal Preliminary data subject to revision
Apr-May-Jun 2018 Temperature Anomalies Non-EC Skill Score: +53 Best possible: +100 No skill: 0 Worst possible: -50 Above normal Near Normal Below Normal Preliminary data subject to revision
Apr-May-Jun 2018 Precipitation Anomalies Non-EC Skill Score: +06 Best possible: +100 No skill: 0 Worst possible: -50 Above normal Near Normal Below Normal Preliminary data subject to revision
Arctic Wide Sea Ice Through July, 2018 Red Line: 2016 Blue line: 2017 Orange line: 2018
Arctic Sea Ice Volume & Thickness End of June Arctic sea ice volume: typical for past 10 years End of June thickness: greater than last year most areas except lower Atlantic and Laptev Sea PIOMAS/U. a Sources: Data from U. Wa./PIOMAS data Graphics by Z. Labe, UC Irvine
Mid-July Sea Ice Comparison July 18, 2018 July 18, 2017
Sea Ice Near Alaska As of July 18 th
Global SST Anomalies June PDO: -0.04 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 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
CPC Niño 3.4 Forecasts: Models Degrees C Warming rest of the summer, strong 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 likely for autumn/winter
2003-2017 Trends August Compared to 1981-2010 00-33=Below normal 34-66=Near normal 67-100=Above normal Temps Aug-Oct Pcpn
Constructed Analogs based on Global SSTs Temperature Outlook Precipitation Outlook
Dynamic Model Forecasts Extratropical SSTs Alaska regional Sea Ice Temp and Pcpn Anomalies
NMME Aug-Oct 2018 SST Departures from Normal Forecast Skill High skill Not much of a PDO pattern
Sea Ice Summer Melt-out Outlook CPC Experimental Forecast
Sea Ice Autumn Freeze-up Outlook CPC Experimental Forecast
August 2018 Temp Anomaly Outlooks Avg Dep ( C) 3-Category Probabilities Calibrated 3-Category Probs Member Averages
August 2018 Pcpn Anomaly Outlooks Avg Dep (mm/day) 3-Category Probabilities Calibrated 3-Category Probs Member Averages
Calibrated Probability Forecasts for August 2018 Forecast from: May June July
Aug-Sep-Oct 2018 Temp Anomaly Forecasts Avg Dep ( C) Category Probs Calibrated Category Probs Member Averages
Aug-Sep-Oct 2018 Pcpn Anomaly Forecasts Avg Dep (mm/day) Category Probs Calibrated Category Probs Member Averages
Calibrated Probability Forecasts for Aug-Sep-Oct 2018 Forecast from: May June July
NMME Skill for August & Aug-Sep-Oct Temp Pcpn
C3S Multi-Model Ensemble for ASO 2018 Average Temperature Category Probabilities Total Precipitation
Aug-Sep-Oct 2018 Outlook from June
And the Answer Is
CPC August 2018 Outlook 65% 30% 05% 45% 22% 37% 30% 37% 45% 30% 55% 22% 12% Above% Normal% Below%
CPC Aug-Sep-Oct 2018 Outlook 65% 30% 05% 65% 30% 05% 45% 22% 45% 55% 12% 37% 30% 22% 37% 30% 30% 37% Above% Normal% Below%
Look Ahead: Fall 2018 65% 30% 05% 45% 22% 37% 30% 55% 12% 45% 22% 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/