John W. Nielsen-Gammon Texas State Climatologist

1. Texas Drought Over? (But then
again…)
John W. Nielsen-Gammon
Texas State Climatologist

2. -10
-8
-6
-4
-2
0
2
4
6
8
10
Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct Jan
PalmerDroughtSeverityIndex
Statewide PDSI, Extreme Texas Droughts Since 1895
1900-1902 1908-1911 1915-1918 1924-1925 1933-1935 1950-1957 1961-1965
1966-1967 1970-1971 1995-1996 1999-2000 2005-2006 2007-2009 2010-2015

3. High-Resolution Drought Monitor
• Daily Stage 4 Precipitation Analysis
(NWS’s River Forecast Centers)
• Historical COOP observations
• PRISM climate normals
• Improved drought metrics

255. -10
-8
-6
-4
-2
0
2
4
6
8
10
Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct Jan
PalmerDroughtSeverityIndex
Statewide PDSI, Extreme Texas Droughts Since 1895
1900-1902 1908-1911 1915-1918 1924-1925 1933-1935 1950-1957 1961-1965
1966-1967 1970-1971 1995-1996 1999-2000 2005-2006 2007-2009 2010-2015

256. Texas Water Storage
Current
Value
Value
when
PDSI
went
positive
Start of
Drought

257. Lake Arrowhead

258. Palo Pinto Reservoir

259. Medina Lake

260. Lake Texoma

264. 8.93
6.66
6.62
6.55
6.45
6.38
6.32
6.26
6.19
6.18
May-15
Jun-04
May-14
Sep-36
May-29
May-35
Sep-74
Oct-19
Apr-57
Nov-04
Ten We est Months in Texas History, 1895-present
(inches)

265. 12.87
11.88
11.81
11.3
11.06
10.87
10.7
10.7
10.13
10.05
Apr-May 2015
Apr-May 1957
Aug-Sep 1974
Sep-Oct 1919
May-Jun 1935
May-Jun 2007
May-Jun 1941
May-Jun 1987
Oct-Nov 2004
Apr-May 1914
Ten We est Two-Month Periods in Texas History,
1895-present (inches)

266. 16.34
16.24
15.8
14.92
14.89
14.29
13.26
13.26
12.99
12.98
Mar-May 2015
May-Jul 2007
Aug-Oct 1974
Apr-Jun 1957
Apr-Jun 1941
Aug-Oct 1919
May-Jul 1919
May-Jul 1935
Apr-Jun 2004
Apr-Jun 1997
Ten We est Three-Month Periods in Texas History,
1895-present (inches)

267. 19.16
18.96
18.41
18.29
18.14
17.79
16.51
16.36
16.19
16.17
May-Aug 2007
Mar-Jun 2015
Aug-Nov 1974
Apr-Jul 1941
Jul-Oct 1919
Mar-Jun 1957
Sep-Dec 1913
Jul-Oct 1971
May-Aug 1914
Apr-Jul 1905
Ten We est Four-Month Periods in Texas History,
1895-present (inches)

268. 27.55
26.77
25.78
24.89
23.94
23.39
22.91
22.73
22.36
22.1
May-Oct 1919
May-Oct 1941
Mar-Aug 2007
Jun-Nov 2004
Apr-Sep 1900
May-Oct 1981
May-Oct 1986
Jan-Jun 2015
Dec-May 1992
May-Oct 1973
Ten We est Six-Month Periods in Texas History,
1895-present (inches)

274. Summary
• Drought all but gone
– Record-setting rainfall for three months and
counting
– Reservoir issues remain in west-central Texas
• El Niño favors a wet fall and winter in
2015-2016
• Will drought cycle bust?

275. Contact Information
• n-g@tamu.edu
• 979-862-2248
• http://climatexas.tamu.edu
• http://climatechangenationalforum.org