2015 Monsoon Season Outlook Daniel Henz Meteorologist Flood Warning Branch Flood Warning Users Workshop June 24, 2015 Phoenix, Arizona Monsoon t-storm looking WNW from Papago Park, , D. Henz

2015 Monsoon Season Outlook June 24, 2015 Phoenix, Arizona Monsoon Outlook (Its complicated…) Image courtesy of SNL

2015 Monsoon Season Outlook June 24, 2015 Phoenix, Arizona Topics For Today

2015 Monsoon Season Outlook June 24, 2015 Phoenix, Arizona Topics For Today

El Niño, What is it? El Niño is the positive (warm) phase of the El Niño Southern Oscillation (ENSO). ENSO is a large scale ocean-atmosphere climate phenomenon occurring in the Equatorial Pacific Ocean Oscillates between positive (warm), neutral, negative (cold) phases in 3-10year cycles Image Courtesy of NOAA/ESRL Ocean: Warm waters central & eastern equatorial Pacific. Atmosphere: Enhanced convection East-Pac 2015 Monsoon Season Outlook June 24, 2015 Phoenix, Arizona

Neutral La Niña El Niño Moderate Strength into 2016

Chances of El Niño continuation through the remainder of the year, ≈90% through Summer, ≥80% through the Winter.Chances of El Niño continuation through the remainder of the year, ≈90% through Summer, ≥80% through the Winter. CPC ENSO Forecast 2015 Monsoon Season Outlook June 24, 2015 Phoenix, Arizona

Chances of El Niño continuation through the remainder of the year, ≈90% through Summer, ≥80% through the Winter.Chances of El Niño continuation through the remainder of the year, ≈90% through Summer, ≥80% through the Winter. CPC ENSO Forecast 2015 Monsoon Season Outlook June 24, 2015 Phoenix, Arizona

Pacific Decadal Oscillation 2015 Monsoon Season Outlook June 24, 2015 Phoenix, Arizona Well Above Normal SST’s have persisted Winter into Spring

Key Large Scale Players 2015 Monsoon Season Outlook June 24, 2015 Phoenix, Arizona Anomalously Warm SST’s: Positive PDO Anomalously Warm SST’s: El Niño

East Pacific Hurricane Outlook 70% chance for an ABOVE AVERAGE Season (May 15 th – November 30 th ) Courtesy of NOAA’s National Hurricane Center Named Storms Average year: Hurricanes Average year: Major Hurricanes Average year: 4

Tropical Cyclone Scorecard (as of mid June) 2015 Monsoon Season Outlook June 24, 2015 Phoenix, Arizona

Historical Monsoon Season Rainfall AZ Tropical System or remnants Onset Moderate/Strong El Niño ?

CPC 3-month Outlooks (Spring/Summer 2015) Jun-Jul-Aug Jul-Aug-Sep Aug-Sep-Oct Forecast Calling For: Early Summer: equal chances for above or below average rain. Early Summer: equal chances for above or below average rain. Late Summer: increasing probability for above average rain (Peak of Pacific hurricane season + strengthening El Ni ñ o response into Fall). Late Summer: increasing probability for above average rain (Peak of Pacific hurricane season + strengthening El Ni ñ o response into Fall) Monsoon Season Outlook June 24, 2015 Phoenix, Arizona

El Niño is HERE and looking to stay a while… El Niño is HERE and looking to stay a while… Below Avg. Rainfall ≠ Reduced Flooding Threat! Below Avg. Rainfall ≠ Reduced Flooding Threat! El Niño + Warm PDO = Active E-Pac TC Season El Niño + Warm PDO = Active E-Pac TC Season Wild Card…(cautious optimism) Wild Card…(cautious optimism) It only takes one widespread heavy rain event to reach the historical Monsoon rainfall quota or even double it! It only takes one widespread heavy rain event to reach the historical Monsoon rainfall quota or even double it! What to Take Away Fearless Forecast: Moderate/Strong El Niño 2015 AZ Monsoon Season: 85%-100% of avg. rainfall, ≈ 2.60”- 3.00” * * Rainfall forecasts above are averaged totals across all Maricopa County ALERT gages * 2015 Monsoon Season Outlook June 24, 2015 Phoenix, Arizona

A Long Look Ahead… (Fall/Winter 2015) Oct-Nov-Dec Dec-Jan-Feb Jan-Feb-Mar CPC Forecast Calls For: Above average rainfall predicted this fall/winter (Oct-Mar) should El Ni ñ o persist & strengthen. Above average rainfall predicted this fall/winter (Oct-Mar) should El Ni ñ o persist & strengthen. Highest probabilities of above avg. rainfall shift south and east: This mimics continuation of El Niño pattern. Highest probabilities of above avg. rainfall shift south and east: This mimics continuation of El Niño pattern Monsoon Season Outlook June 24, 2015 Phoenix, Arizona

Chances of El Niño continuation through the remainder of the year, ≈90% through Summer, ≥80% through the Winter.Chances of El Niño continuation through the remainder of the year, ≈90% through Summer, ≥80% through the Winter. CPC ENSO Forecast 2015 Monsoon Season Outlook June 24, 2015 Phoenix, Arizona

El Niño observational and forecast images, Climate Prediction Center: Historic Monsoon rainfall data, NWS Tucson WFO: Satellite Imagery, Unisys Weather: SST Anomaly Data, NOAA/NESDIS: Correlation Plots, NOAA/ESRL, PSD: Historic ALERT rainfall data, Flood Control District of Maricopa County: El Niño and La Niña Episodes and Their Impact on the Weather in the Tucson Metropolitan Area: Glenn Lader, WFO Tucson, AZ, 2012: Data Sources/References 2015 Monsoon Season Outlook June 24, 2015 Phoenix, Arizona

Thank You! Questions…? Monsoon Season Outlook June 24, 2015 Phoenix, Arizona