State Climate Update for Arizona – Conditions through November 2005

 

 

November 2005                                                                                                                                                                                                                 

The month of November was warm and very dry across the state. The mean monthly temperature ranked between the 77th percentile in northeastern Arizona (CD 2) and the 93rd percentile in south-central Arizona (CD 6). The warmth compounded the problem of dryness, as precipitation totals were well below average across every region of the state. A precipitation amount suggestive of ‘extreme drought’ was recorded for southeastern Arizona (CD 7; driest November on record), while precipitation was suggestive of ‘severe drought’ for November across northeastern (CD 2), east-central (CD 4), and south-central (CD 6) portions of the state. Elsewhere, precipitation was suggestive of either ‘moderate drought’ (west-central; CD 3) or ‘abnormally dry’ (northwestern, southwestern; CDs 1 and 5) conditions for November. A residual of winter 2004-05, Palmer Drought Severity Index values continue to indicate rather moist conditions across much of the state, except for in east-central (CD 4) and southeastern (CD 7) Arizona, where rather large changes in the PDSI toward low values, or dry conditions, occurred.

 

 

Temperature

Precipitation

PDSI

CD1

86.5%

27.9% (1)

91.9%

CD2

77.5%

11.7% (3)

75.7%

CD3

86.5%

23.4% (2)

81.1%

CD4

82.9%

13.5% (3)

26.1%

CD5

92.8%

25.2% (1)

98.2%

CD6

93.7%

14.4% (3)

83.8%

CD7

86.5%

0.9% (4)

21.6%

 

1-month percentiles of temperature, precipitation (with drought category), and Palmer Drought Severity Index for the 7 Arizona climate divisions


 

 

September 2005 – November 2005                                                                                                                                                                              

Except for across western Arizona (CDs 1 and 5), the fall season was very dry across the state. Most problematic were precipitation totals across northeastern (CD 2), south-central (CD 6), and southeastern (CD 7) Arizona, where conditions suggestive of ‘severe drought’ existed. Slightly better seasonal conditions existed in central Arizona (CDs 3 and 4) where precipitation totals indicated Fall to be ‘abnormally dry’. Temperatures for the three-month period were high, with the greatest warmth in southwestern and south-central Arizona (CDs 5 and 6; 93rd and 96th percentiles).

 

 

 

Temperature

Precipitation

CD1

83.8%

41.4% (0)

CD2

79.3%

12.6% (3)

CD3

84.7%

22.5% (2)

CD4

82.9%

15.3% (2)

CD5

93.7%

56.8% (0)

CD6

96.4%

12.6% (3)

CD7

87.4%

9.0% (3)

 

3-month percentiles of temperature, and precipitation (with drought category) for the 7 Arizona climate divisions


 

June 2005 – November 2005                                                                                                                                                                                          

Six-month precipitation values representing conditions across the summer and fall seasons again indicate dryness for all of Arizona except for the western portion of the state (CDs 1 and 5).  The driest 6 months occurred in two areas of the state riddled by drought over the past 6-9 years: southeastern (CD 7:  ‘extreme drought’) and east-central (CD 4; ‘severe drought’) Arizona. Dry conditions characterize the northeastern (CD 2; ‘moderate drought’) and west-central and south-central (CDs 3 and 6; ‘abnormally dry’) parts of the state. Statewide, temperatures from late spring through early fall were considerably above the long-term median, and approaching unprecedented levels across the southern tier of the state (CDs 5, 6, and 7).

 

 

 

Temperature

Precipitation

CD1

79.3%

58.6% (0)

CD2

68.5%

18.9% (2)

CD3

80.2%

27.0% (1)

CD4

74.8%

12.6% (3)

CD5

90.1%

73.0% (0)

CD6

94.6%

38.7% (1)

CD7

92.8%

4.5% (4)

 

6-month percentiles of temperature, and precipitation (with drought category) for the 7 Arizona climate divisions


 

December 2004 – November 2005                                                                                                                                                                                

There is no evidence of drought within the state when examining precipitation totals for the past 12-month period. In fact, most regions were characterized by well above normal precipitation, including totals in the 90th percentile for 4 of the 7 regions. The relatively drier area continues to be across the southeast (CD 7; 42nd percentile). Temperatures across the state were above normal for the past 12-month period, and most significantly so across the southern (CDs 5, 6, and 7) and northeastern (CD 2) parts of the state.

 

 

Temperature

Precipitation

CD1

80.9%

94.6% (0)

CD2

89.1%

90.9% (0)

CD3

84.6%

90.0% (0)

CD4

81.8%

84.6% (0)

CD5

88.2%

95.5% (0)

CD6

95.5%

89.1% (0)

CD7

90.9%

42.7% (0)

 

12-month percentiles of temperature, and precipitation (with drought category) for the 7 Arizona climate divisions


 

December 2003 – November 2005                                                                                                                                                                                

Twenty-four month precipitation values continue to indicate rather wet conditions across the state, as all regions but the southeast (CD 7) were comfortably above the long-term median value, and well above across the western portion of the state. The 2-year precipitation total was characteristic of “abnormally dry” conditions across southeastern Arizona (CD 7), the driest region over the past two years, and in great contrast to the southwestern part of the state (CD 5). In the latter region, the past 24-month December-November period was the fourth wettest on record. Mean temperatures for the 2-year period were rather high across the state, but less so in the northwestern (CD 1) and southeastern (CD 7) portions of the state.

 

 

Temperature

Precipitation

CD1

79.8%

94.5% (0)

CD2

89.0%

78.0% (0)

CD3

88.1%

86.2% (0)

CD4

94.5%

62.4% (0)

CD5

88.1%

97.3% (0)

CD6

90.8%

80.7% (0)

CD7

79.8%

27.5% (1)

 

24-month percentiles of temperature, and precipitation (with drought category) for the 7 Arizona climate divisions


 

December 2002 – November 2005                                                                                                                                                                                

Precipitation totals for the longer-term 3-year period indicate conditions that are not as wet when considering the past two years; however, the 36-month precipitation totals were above average for 5 of the 7 climatic regions in Arizona, with another region (east-central, CD 4) very near average (48th percentile). Only across the southeastern portion of the state (CD 7; 15th percentile) did the precipitation fall far below average. Here, the total precipitation for the period is suggestive of ‘severe drought’ conditions. Temperatures for the period were well above the historical median; however, to some extent the longer 3-year time period likely reflects the more general climatic changes of the past several decades.

 

 

Temperature

Precipitation

CD1

84.3%

86.1% (0)

CD2

92.6%

67.6% (0)

CD3

94.4%

74.1% (0)

CD4

97.2%

48.2% (0)

CD5

92.6%

94.4% (0)

CD6

95.4%

72.2% (0)

CD7

88.9%

15.7% (3)

 

36-month percentiles of temperature, and precipitation (with drought category) for the 7 Arizona climate divisions


 

December 2001 – November 2005                                                                                                                                                                                

Forty eight-month precipitation values indicate clear evidence of longer-term drought conditions across two areas of the state, with abnormally dry conditions across another two areas. All regions within the state, except for the northwest (CD 1) and southwest (CD 5), have been characterized by less than average precipitation over the 4-year period. Precipitation totals for the period indicate ‘abnormally dry’ conditions across the west-central (CD 3) and south-central (CD 6) portions of the state. Long-term conditions suggestive of ‘severe drought’ exist across southeastern (CD 7) and east-central (CD 4) Arizona, as both are characterized by 48-month precipitation that is in the 9th-10th percentile range. Temperatures for the 4-year period are near unprecedented highs but, again, this is likely to be at least somewhat of a reflection of longer-term trends rather than shorter-term anomalies.

 

 

Temperature

Precipitation

CD1

85.1%

52.3% (0)

CD2

92.5%

41.1% (0)

CD3

97.2%

33.6% (1)

CD4

98.1%

9.4% (3)

CD5

93.5%

81.3% (0)

CD6

95.3%

36.5% (1)

CD7

95.3%

10.3% (3)

 

48-month percentiles of temperature, and precipitation (with drought category) for the 7 Arizona climate divisions


 

 

  

 

Summary                                                                                                                                                                                                                            

November 2005 was characterized by warmth and dryness across the entire state, including the driest November on record for southeastern Arizona. Except for across east-central and southeastern Arizona, the wet fall and winter conditions of 2004-05 were still reflected in high (wet) Palmer Drought Index Values for much of the state. This may be a bit misleading, as of concern is the re-emergence of dry conditions across much of the state, especially in southeastern and east-central Arizona, over the past 3-6 months. In southeastern Arizona, the 6-month precipitation total was the 5th driest in the past 111 years.

 

On the longer term, there exists little or no evidence of drought across Arizona over the past 12-to-24 months, with generally much greater than normal precipitation during the period. However, long-term drought is clearly evident on the 36-month time frame across southeastern Arizona, and dryness and drought across east-central and southeastern Arizona is obvious on the 48-month time frame.

 

Overall, the southeastern and east-central regions of Arizona continue to struggle with long-term precipitation totals suggestive of drought, and recent precipitation totals indicate re-emerging dry conditions.