2010-2011 Drought Jeffrey Lindner Meteorologist Harris County Flood Control District September 20, 2011 Texas Annual Rainfall Texas Annual Rainfall 1895-2010 Texas Annual Temperature 1895-2010 Notice Any Trends? Texas Spring Rainfall 1895-2010 Less Spring rainfall since 1950 Texas Summer Rainfall 1895-2010 Greater summer rainfall since 1960 Texas Fall Rainfall 1895-2010 Greater Fall rainfall since 1960 Texas Winter Rainfall 1895-2010 Less winter rainfall since 1950 Texas Climate Trends • Drier winter and spring seasons since 1950 • Wetter summer and fall seasons since 1960 • Overall Texas annual rainfall has been greater since 1960 compared 1895-1960 • Drought was much more common, long term, and severe pre 1960 • Annual temperatures have been above average since 1996 2010 Texas Rainfall 2010 Texas Rainfall Departures DRY WET 2010-2011 Texas Rainfall Departures (Sept 10-Sept 11) 2011 Drought Conditions 2011 Summer Heat Days at or above 100: Most Consecutive 100 degree days: Houston IAH: 46 (32 in 1980) Houston IAH: 24 (14 in 1980) Hobby: 18 (13 in 1998/2000) Austin: 27 (21 in 2001) Conroe: 52 (42 in 1998) Dallas: 40 (42 in 1980) Huntsville: 70 (43 in 1980) Waco: 44 (42 in 1980) College Station: 66 (58 in 1917) Dallas: 62 (69 in 1980) Top 4 Warmest months for Texas ever: Waco: 76 (63 in 1980) July 2011: 87.2 Austin Mabry: 84 (69 in 1925) July 1998: 86.5 San Antonio: 54 (59 in 2009) July 1980: 86.3 Del Rio: 81 (78 in 1953) August 1952: 85.7 Houston tied all-time record high of 109 on 8-27-11 Galveston: 100 on 8-27-11 for only the 7th time ever July 2011 warmest month ever for the state of Texas: 87.2 degrees breaking the previous record of 86.5 degrees in July 1998 Hottest June-August period ever! 2011 Drought Conditions Lake Levels and Capacity Sept 19 Lake Conroe: -5.62 (75%) Lake Houston: -8.07 (61%) Lake Livingston: -3.30 (84%) Lake Somerville: -9.52 (42%) Lake Texana: -11.07ft (46%) Lake Buchanan: -28.24 (41%) Lake Travis: -49.81 (38%) Lake Georgetown: -23.16 (38%) Lake Travis Toledo Bend: -11.18 (61%) Sam Rayburn: -12.45 (58%) Lake Houston Lake Travis Conservation Storage Statistics -TWDB <> 2011 Drought Conditions Mandatory: 33 Voluntary: 34 September 9 March 30 Mandatory: 583 Voluntary: 294 Texas Wildfires 11/15/2010-9/12/2011 April 2011 • 3.6 million acres burned • 19,855 fires • 48,613 structures threatened • 4,376 structures burned • 49 states responding 4 out of the 10 largest TX fires occurred in April 2011 Texas Wildfires – Labor Day Weekend Bastrop Complex: 34,036 acres 2 fatalities 1554 homes lost 5,000 evacuated 1351 ground personnel, 14 aircraft Tri-County: 18,638 acres 63 homes lost (23 damaged) 12 large fires, Labor Day 2011 8,000 evacuated 698 ground personnel, 16 aircraft Texas Burn Ban Map: August 2011 251 out of 254 counties under burn bans, old record was 221 in 2006 Current Soil Moisture Conditions KBDI Index AUSTIN 751 GALVESTON 729 BRAZOS 762 BURLESON 775 BASTROP 789 COLORADO 773 FORT BEND 739 GRIMES 761 HARRIS 751 HOUSTON 771 JACKSON 765 LIBERTY 709 MADISON 773 MATAGORDA 738 MONTGOMERY 777 POLK 701 SAN JACINTO 763 TRINITY 745 WALKER 773 WALLER 758 WASHINGTON 774 WHARTON 756 2010-2011 Drought Top 5 Driest Feb-Sept 15 Periods for Houston: 2011 – 5.95 in (21.4% of normal) 1917- 13.93 in 1930- 15.44 in 7.98 inches of rain required at IAH to 1965 – 15.76 in move to second place and 7.34 inches at 1956 – 15.93 in Hobby Top 5 Driest Jan 1-Sep 15 Periods for Houston: 2011- 11.00 in 1917-15.22 in 1965- 18.38 in 1930 – 18.96 in 1901 – 19.06 in Texas Drought Rankings 1.1950-1957 (Sept 1956 peak) 2. 2010-? 3. 1916-1918 (Aug 1918 peak) 4. 1924-1925 (July 1925 peak) 5. 1999-2000 (Sept 2000 peak 2010-2011 Drought Rainfall Deficits (Oct 10 to Sept 15) Rainfall Deficits since Hurricane Ike Bellville: -26.55 Brenham: -26.80 Galveston: -41.52 College Station: -24.84 Houston IAH: -29.02 Columbus: -26.82 Houston Hobby: -34.98 Conroe: -29.96 College Station: -28.84 Freeport: -30.26 Richmond: -41.48 Hobby: -29.81 Bay City: -36.51 IAH: -28.87 Wharton: -34.94 Katy: -26.59 Livingston: -32.82 Matagorda: -28.28 Huntsville: -29.08 Tomball: -35.89 Have been in mild drought since Ike, but the last 8 months have been brutal October 2010 to August 2011: Driest October to August period ever for state of TX 2010-2011 Drought • 2nd worst in SE TX based on rainfall behind 1917-1918 (likely worst in some areas) • 2nd worst drought in TX history (behind 1917/1918 and 1950’s) • Driest April ever at Houston (.11 of an inch), driest Spring ever for Houston • Driest year to date ever for the City of Houston • .32 of an inch of rain at Del Rio Oct 10-April 11 • At least 5.1 billion in economic losses so far, 90% of corn crop failed •Tremendous impacts on livestock, vegetation, economy •1.2 million trees lost, estimate 66 million in two years (10% of area canopy) 2010-2011 Drought Most areas would require 15-28 inches of rainfall to bring them to near normal conditions and end the drought 2011-2012 ENSO Forecast Models La Nina Impacts La Nina Impacts 2011 Drought Forecast Rainfall Forecast 8-14 1 month days 3 months Questions .