National Weather Service United States Department of Commerce

Active Weather Pattern Continues for the Northwestern U.S.

A series of Pacific storm systems will bring periods of locally heavy rain, gusty winds, and mountain snow to portions of Washington and Oregon for the next couple days. In addition, much of the northwestern U.S. and Intermountain West will experience strong winds from these storm systems, particularly in Sierra Nevada, Great Basin, and the northern Rockies/High Plains. Read More >

Current Data and Statistics

Palmer Drought Severity Index

 

The Palmer Index was developed in the 1960s and uses temperature and rainfall information in a formula to determine dryness. The Palmer Index is most effective in determining long term drought (a matter of several months) and is not as good with short-term forecasts (a matter of weeks). Click on the image to enlarge.

The Palmer Index uses a 0 as normal, and drought is shown in terms of minus numbers; for example, minus 2 is moderate drought, minus 3 is severe drought, and minus 4 is extreme drought.The Palmer Index can also reflect excess rain using a corresponding level reflected by plus figures; i.e., 0 is normal, plus 2 is moderate rainfall, etc.

The advantage of the Palmer Index is that it is standardized to local climate, so it can be applied to any part of the country to demonstrate relative drought or rainfall conditions. The negative is that it is not as good for short term forecasts, and is not particularly useful in calculating supplies of water locked up in snow, so it works best east of the Continental Divide.

Palmer Drought Severity Index     

Keetch-Byram Drought Index

 

Drought indices by climatic division often average out much of the variance within a region. The images below show the Keetch-Byram Drought Index for all the counties of Oklahoma and Texas. Click on the image to enlarge.

Keetch-Byram Drought Index for Oklahoma
 
Keetch-Byram Drought Index for Texas
 

Temperature Records

 
Top Ten All-time Monthly Temperature Records
Oklahoma City, OK (1890 - Present) Wichita Falls, TX (1921 - Present)
Rank Warmest Month/ Year Rank Warmest Month/year
1 89.2 July 2011 1 93.4 August 2011
2 89.0 August 2011 2 92.9 July 2011
3 88.7 August 1936 3 91.9 July 1980
4 (t) 88.3 July 1980 4 91.1 August 1952
  88.3 July 1934 5 90.7 August 1943
6 (t) 88.0 July 1998 6 90.3 August 2000
  88.0 August 1980 7 90.0 July 2001
8 87.4 July 1954 8 89.9 July 1978
9 87.2 August 1943 9 89.8 July 1934
10 87.0 July 1978 10 89.5 June 2011
(t)=tie
 

Oklahoma Climatological Survey Precipitation Statistics for the Current Calendar Year

 

Current precipitation and drought condition information for Oklahoma can be found through the Oklahoma Climatological Survey web site.

Total Precipitation
Normal Precipitation
Total Precipitation for Oklahoma for the Calendar Year Normal Precipitation for Oklahoma for the Calendar Year
Departure
Percentage Normal
Precipitation Departure from Normal for Oklahoma for the Calendar Year Precipitation Percentage of Normal for Oklahoma for the Calendar Year
 

Longest Streaks Without Precipitation

 
Longest Streaks Without Precipitation for Wichita Falls, TX
Rank # of Days Date Range
1 75 December 19, 1913 - March 3, 1914
2 72 May 31, 2001 - August 10, 2001
3 71 November 1, 1904 - January 10, 1905
4 66  September 7, 1901 - November 11, 1901
5 65  June 30, 1943 - September 2, 1943
6 62  October 4, 1950 - December 4, 1950
7 (tie) 59  January 2, 1996 -  March 16, 1996
  59  July 6, 1936 - September 2, 1936
9 (tie) 55 June 15, 2011 - August 8, 2011
  55  August 20, 1956 - October 13, 1956
  55  October 6, 1955 - November 29, 1955
 
Longest Streak Without Precipitation for Oklahoma City, OK
Rank # of Days Date Range
1 68 October 21, 1910 - December 27, 1910
2 56 October 5, 1955 - November 29, 1955
3 54 July 30, 2000 - September 21, 2000
4 53 December 7, 1922 - January 28, 1923
5 (tie) 50 December 14, 1985 - February 1, 1986
  50 December 2, 1955 - January 20, 1956
7 47 September 23, 1952 - November 8, 1952
8 44 September 30, 1958 - November 12, 1958
9 44 July 2, 1913 - August 14, 1913
10 43  February 3, 1996 - March 16, 1996
 

Drought Impact Reporter from the National Drought Mitigation Center

 

Drought severity is inherently linked to the impacts of the drought. Such impacts include agricultural issues, hydrologic deficits, increased fire danger, and other economic and social consequences. These impacts are not easily quantified with simple statistics.

The National Drought Mitigation Center developed the Drought Impact Reporter as a database for reported drought impacts. The impacts are classified by category, with the number of reports emphasizing a drought's significance without attributing specific statistics to the reports. (Click on a county of interest for further information.)


 

WHAT'S THE OUTLOOK OVER THE NEXT FEW MONTHS ?

 

U.S. Seasonal Drought Outlook

 
U.S. Seasonal Drought Outlook
 

How Much Rain Do We Need?

 

How much rain is needed to get the Palmer Drought Severity Index back to the "near normal" category? Click below to find out.

Precipitation Needed to Return to Normal
 

When Will It End?

 

CPC 1-month Precipitation Outlook
CPC 1-month Precipitation Outlook

CPC 3-month Precipitation Outlook
CPC 3-month Precipitation Outlook


 

Web Links