1. Historical Texas Drought Update LCRA Firm Water Customer Meeting October 27, 2011 Bob Rose, LCRA Meteorologist

2. Worst Drought in Texas History “This is state’s most severe one-year drought in recorded history” John Nielsen-Gammon, Texas State Climatologist. Driest October-September on record with 7.18 inches. Normal is 14.94. Record low was 7.35 inches Oct 1901-Sep 1902.

3. 7.18 in. 7.35 in. Texas Rainfall, Oct.-Sep.

4. Austin’s Driest 12-Month Period in History 1.OCT. 2010 TO SEP. 2011 11.20 2.JAN. 1954 TO DEC. 1954 11.42 3.OCT. 1924 TO SEP. 1925 11.83 4.OCT. 1955 TO SEP. 1956 12.18 5. MAY 1977 TO APR. 1978 14.44 NOV. 1916 TO OCT. 1917 14.44 6.JUN. 1970 TO MAY 1971 15.06 7.SEP. 2008 TO AUG. 2009 15.38 8.SEP. 1878 TO AUG. 1879 15.52 9.OCT. 1983 TO SEP. 1984 16.86 10. JUL. 1993 TO JUN. 1994 17.01

5. Rainfall Oct 2010-Sep 2011

6. Rainfall Departure from Normal October 2010-September 2011

7. Unprecedented Summer Heat!! !

9. Temperature Departure from Normal, 6/1-8/31

10. Unprecedented Summer Heat Second hottest summer ever recorded, for any state. Average temperature 86.7 degrees. (Oklahoma was first with 86.8) Austin recorded its hottest April, July, August and September on record. June was second hottest. Austin recorded 90 days at or above 100 degrees. 165 days at or above 90 degrees.

11. Rainfall, October 7-9

13. Going into Second Year of La Niña January 6th October 24th

14. Typical Patterns Associated with La Niña

15. La Nina

16. WetDry

17. Temperature Precipitation

18. NWS Winter into Spring Rainfall Outlook

19. Drought Outlook through January

20. Jan-March Anomalies Based on 2 nd Year La Niña

21. April-May Anomalies Based on 2 nd Year La Niña

22. June-Aug Anomalies Based on 2 nd Year La Niña

23. Ending Drought in 1 Month

24. Rain Needed to End the Drought in 6 Months

25. The 2011 Atlantic Hurricane Season

26. An Active Season, but Not for Texas

27. Take Home Points No clear end in sight to the ongoing drought; could last well into 2012. Scattered rains possible this fall and winter but not heavy enough to temper the drought. Intense droughts are hard to break. Tropical storms rains now not likely. La Niña is back. Late fall and winter expected to be drier than normal. Dry years interspersed with wet years.

28. Bob Rose Meteorologist, LCRA bob.rose@lcra.org512-473-3350