Climate Outlook

1. Climate Outlook Jayantha Obeysekera (’Obey’), Ph.D.,P.E.,D.WRE Department Director Hydrologic & Environmental Systems Modeling

2. Case Study: Lake Okeechobee • Operation of Lake Okeechobee requires a balance between multiple objectives. • Climate outlook has been incorporated into operations. Climate based operations are designed to balance current release decisions with future potential shortages and/or surpluses. • Position Analysis is a tool for projecting probabilities associated with future lake levels. It is a valuable tool for Lake Okeechobee operations.

3. Lake Okeechobee Management Objectives • Protect the integrity of the Dike • Protect Estuaries • Meet Agricultural/Urban Water Supply needs • Maintain a healthy Littoral Zone • Provide water to Everglades • Maintain Navigation

4. Balancing the Objectives undesirable desirable

5. Water Shortage Lake Okeechobee Management Zones Flood Control

6. WSE Operational Guidelines Decision Tree Part 2: Define Lake Okeechobee Discharges to Tidewater (Estuaries) Apply Tributary Condition Criteria Weekly Check Special Lake Criteria daily as needed for Zones B & D Apply Meteorological Forecasts on a Weekly Basis; apply Seasonal and Multi-Seasonal Climate Outlooks on a Monthly Basis Up to Maximum Discharge Capacity To Tidewater ZONE A Up to 30 day Meteorological Forecast EXTREMELY WET Zone B Steady Flow S-80 Up to 3500cfs S-77 Up to 6500cfs Tributary Hydrologic Conditions WET TO VERY WET NORMAL TO VERY WET Seasonal Climate Outlook ZONE B Up to Maximum Pulse Release to the Estuaries NORMAL TO VERY WET FALSE NORMAL TO DRY Up to 30 day Meteorological Forecast Lake Less than 17.5’ & it’s the Dry Season TRUE DRY DRY START Lake Okeechobee Water Level Up to Zone B S-80 Up to 3500cfs S-77 Up to 6500cfs Up to 30 day Meteorological Forecast EXTREMELY WET WET TO VERY WET Zone C Steady Flow S-80 Up to 2500cfs S-77 Up to 4500cfs Tributary Hydrologic Conditions WET TO VERY WET NORMAL TO DRY ZONE C EITHER FORECAST INDICATES WET TO VERY WET Up to Maximum Pulse Release to the Estuaries NORMAL TO VERY WET Seasonal Climate Outlook Multi- Seasonal Climate Outlook NORMAL TO DRY BOTH FORECASTS INDICATE NORMAL TO DRY No Discharge to Tidewater & Meteorological Forecast DRY Lake Stage within 0.5 feet of Zone C Seasonal Climate Outlook Up to Zone C S-80 Up to 2500cfs S-77 Up to 4500cfs EXTREMELY WET VERY WET TRUE Tributary Hydrologic Conditions OTHERWISE WET TO VERY WET FALSE ZONE D TRUE NORMAL Seasonal Climate Outlook Lake Stage within 0.5 feet of Zone C Multi- Seasonal Climate Outlook WET TO VERY WET Up to Maximum Pulse Release to the Estuaries FALSE VERY WET OTHERWISE DRY NORMAL TO DRY No Discharge to Tidewater

7. WSE Regulation ScheduleOperational Elements • Lake Okeechobee Water Level • Tributary Hydrologic Condition • 30 Day Net Rainfall • Average Kissimmee River (Tributary watershed) inflow • Lake Okeechobee Net Inflow Outlook • Seasonal Outlook (6 month) • Multi-seasonal Outlook (7 to 12 months)

8. Climate Outlook IndicatorsEl Niño/La Nina ( Roller Coaster )

9. warm warm cold cold Climate Outlook Indicators: Atlantic Multidecadal Oscillation (AMO) • Decadal to multi-decadal scale fluctuations in the sea surface temperature (only about 1º F) in the North Atlantic Ocean • Cold Phase (~1900-1925, 1970-1994) • Warm Phase (1926-1969, 1995-???)

10. Summary of What We Know(These are tendencies and not absolutes!)

11. WSE Operational Guidelines Decision Tree Part 2: Define Lake Okeechobee Discharges to Tidewater (Estuaries) 16.75 16.5 (Zone C) 16.25 DRY DRY DRY 6 3 1 Apply Tributary Condition Criteria Weekly Check Special Lake Criteria daily as needed for Zones B & D Apply Meteorological Forecasts on a Weekly Basis; apply Seasonal and Multi-Seasonal Climate Outlooks on a Monthly Basis Up to Maximum Discharge Capacity To Tidewater ZONE A Up to 30 day Meteorological Forecast EXTREMELY WET Zone B Steady Flow S-80 Up to 3500cfs S-77 Up to 6500cfs Tributary Hydrologic Conditions WET TO VERY WET NORMAL TO VERY WET Seasonal Climate Outlook ZONE B Up to Maximum Pulse Release to the Estuaries NORMAL TO VERY WET FALSE NORMAL TO DRY Up to 30 day Meteorological Forecast Lake Less than 17.5’ & it’s the Dry Season TRUE DRY DRY START Lake Okeechobee Water Level Up to Zone B S-80 Up to 3500cfs S-77 Up to 6500cfs Up to 30 day Meteorological Forecast EXTREMELY WET WET TO VERY WET Zone C Steady Flow S-80 Up to 2500cfs S-77 Up to 4500cfs Tributary Hydrologic Conditions WET TO VERY WET NORMAL TO DRY ZONE C EITHER FORECAST INDICATES WET TO VERY WET Up to Maximum Pulse Release to the Estuaries NORMAL TO VERY WET Seasonal Climate Outlook Multi- Seasonal Climate Outlook NORMAL TO DRY BOTH FORECASTS INDICATE NORMAL TO DRY No Discharge to Tidewater & Meteorological Forecast DRY Lake Stage within 0.5 feet of Zone C Seasonal Climate Outlook Up to Zone C S-80 Up to 2500cfs S-77 Up to 4500cfs EXTREMELY WET VERY WET TRUE Tributary Hydrologic Conditions OTHERWISE WET TO VERY WET FALSE ZONE D TRUE NORMAL Seasonal Climate Outlook Lake Stage within 0.5 feet of Zone C Multi- Seasonal Climate Outlook WET TO VERY WET Up to Maximum Pulse Release to the Estuaries FALSE VERY WET OTHERWISE DRY NORMAL TO DRY No Discharge to Tidewater

12. Middle 50% Lake Okeechobee November 15, 2007 Position Analysis

13. Questions?