2015 monsoon season outlook daniel henz meteorologist flood warning branch flood warning users...
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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, 08-17-2014, 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.
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32
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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.
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.
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 15th – November 30th)
Courtesy of NOAA’s National Hurricane Center
15-22 Named StormsAverage year: 15
7-12 HurricanesAverage year: 8
5-8 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.
• Late Summer: increasing probability for above average rain (Peak of Pacific hurricane season + strengthening El Niño response into Fall).
2015 Monsoon Season Outlook • June 24, 2015 • Phoenix, Arizona
El Niño is HERE and looking to stay a while…
Below Avg. Rainfall ≠ Reduced Flooding Threat!
El Niño + Warm PDO = Active E-Pac TC Season Wild Card…(cautious optimism)
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 Niño persist & strengthen.
• Highest probabilities of above avg. rainfall shift south and east: This mimics continuation of El Niño pattern.
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.
CPC ENSO Forecast
2015 Monsoon Season Outlook • June 24, 2015 • Phoenix, Arizona
• El Niño observational and forecast images, Climate Prediction Center: http://www.cpc.ncep.noaa.gov/
• Historic Monsoon rainfall data, NWS Tucson WFO: http://www.wrh.noaa.gov/twc/monsoon/monsoon_tracker.php
• Satellite Imagery, Unisys Weather: http://weather.unisys.com/archive/sat_ir/
• SST Anomaly Data, NOAA/NESDIS: http://www.ospo.noaa.gov/Products/ocean/sst/anomaly/
• Correlation Plots, NOAA/ESRL, PSD: http://www.esrl.noaa.gov/psd/data/usclimdivs/correlation/
• Historic ALERT rainfall data, Flood Control District of Maricopa County: http://www.fcd.maricopa.gov/Rainfall/rainfall.aspx
• El Niño and La Niña Episodes and Their Impact on the Weather in the Tucson Metropolitan Area: Glenn Lader, WFO Tucson, AZ, 2012: http://www.wrh.noaa.gov/wrh/talite1201.pdf
Data Sources/References
2015 Monsoon Season Outlook • June 24, 2015 • Phoenix, Arizona
Thank You! Questions…?
www.fcd.maricopa.gov@FCDFloodInfo
www.facebook.com/FCDMaricopa
2015 Monsoon Season Outlook • June 24, 2015 • Phoenix, Arizona