1. U N I T E D S T A T E S D E P A R T M E N T O F C O M M E R C E N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N What We’ve Heard Thus Far: ACF Basin Outlook and Impacts 1 David Brown December 1, 2011

2. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N Today’s gathering is a very specific example of regional climate services in action – Promoting the delivery of region-specific climate information to a diverse community of users Introduction

3. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N Today’s gathering is a very specific example of regional climate services in action – Promoting the delivery of region-specific climate information to a diverse community of users But – much of the information is highly technical Introduction

4. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N Today’s gathering is a very specific example of regional climate services in action – Promoting the delivery of region-specific climate information to a diverse community of users But – much of the information is highly technical What we (NOAA etc.) need to remember is – how do we package long-term (climate) information in a way that is useful for (short- term) decision-making? (W. Rooks, ~8:30am) Introduction

5. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N ACF Outlook and Impacts Looking at Last Winter

6. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N When we met in Albany in Nov 2010 – strong La Nina was in place, and the forecast for continued La Nina throughout the winter did verify – Impact on rainfall across ACF generally as expected: drier-than-normal in the north, somewhat wetter than expected to south – Impact on temperatures across ACF not as expected: AO/NAO led to unusually cold December; some return to above-normal temperatures in Jan/Feb Spring impacts were largely La Nina-like Dave Z – Review of 2010

7. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N ACF Outlook and Impacts Current Conditions

8. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N ACF Basin “dancing on the edge” of significant, long-term drought especially in southwest GA – Based on season-to-date and year-to-date precip There has been some short-term improvement in conditions over the past 60-90 days, which has helped ameliorate some of the drought risk 2011-2012 winter and spring recharge in the ACF Basin will be crucial in determining the persistence and intensity of drought conditions Victor M – Current Conditions

9. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N ACF Outlook and Impacts Winter and Long-Lead Outlooks

10. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N La Nina has redeveloped and is expected to persist throughout the winter – AO/NAO continues to be erratic and difficult to predict – like last winter, it is possible that short-term variations could be more dominant than the La Nina signal, for short periods (especially for temperature) Expected La Nina impacts for this winter: – Better chance for warmer-than-normal temperatures – Better change for drier-than-normal precipitation Bottom line: drought likely to persist in ACF Mike H – Winter Outlook

11. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N Forecast for the primary recharge period (winter and spring) for ACF Basin is as follows: – Greatest likelihood is for below-normal inflows into Lake Lanier – Greatest likelihood is for below-normal streamflow in the Flint, Chattahoochee, and Apalachicola Rivers There is some uncertainty in these outlooks – Factors other than La Nina can become dominant over short periods (e.g., AO/NAO) Jeff D – La Nina & ACF Recharge

12. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N La Nina is back It will continue through the winter But, this La Nina is weaker than last winter’s Slight odds of a third winter of La Nina conditions in 2012-2013 (“triple delight”) Any return to El Nino in 2012 would likely benefit ACF (but historically, more reliable impact would be in other drought-stricken areas such as Texas) Klaus – La Nina Forecast

13. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N ACF Outlook and Impacts Current Impacts

14. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N Lake Lanier and other ACF reservoirs are unlikely to recover during upcoming recharge period Several “system drivers” during current drought: – “Balanced system” operations – State water quality flow requirements – Revised Interim Operating Plan (most demanding) Until recharge season begins, Corps will store as water while meeting basin-wide needs Corps management decisions utilize both short- (e.g., QPFs) and long-term (e.g., CPC) information Bailey C – Reservoir Update

15. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N Observed impacts in ACF from ongoing drought: – Delayed planting (corn and peanuts) – Delayed emergence (peanuts) – Slow early season crop growth development (all) – Above-normal irrigation needs (corn and peanuts) – Delayed fruit set and maturity due to heat (peanuts) – Increased field abandonment (corn and peanuts) – Pronounced yield impacts (cotton, corn, peanuts) Impacts less in northern Alabama/Georgia Brenda O – Agriculture Update

16. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N Recent droughts have resulted in lower stream flows than those prior to development activities Potential impacts in ACF from ongoing drought: – Loss of habitats, stream aeration, and fish passage – Stressed or lost aquatic life – Reduced assimilative capacity, recreational activity, water supply, and stream health System is already stressed – Record minimum flows in 2011 in Lower Flint Steve G – Ecosystems Update

17. N A T I O N A L O C E A N I C A N D A T M O S P H E R I C A D M I N I S T R A T I O N Did we miss any key points? Is there anything else to add? Will this summary be useful to decision-makers within the ACF Basin? Questions