April 2012 Statewide Summary

Temperature

In contrast to March, which recorded below normal temperatures, April 2012 was seasonably too warm. 15 of the 20 first order meteorological stations in Alaska reported positive deviations. A mean deviation of all 20 stations from the long-term mean could be calculated as +1.3°F. The stations with positive deviations larger than +4°F were found in Interior Alaska; they are, in declining order, the following: Big Delta (+5.5°F), Bettles (+5.0°F) and Fairbanks (+4.4°F). April's above normal temperatures in the Interior resulted also in an early breakup of the Tanana River. The ice went out at Nenana at the 23rd of April; the 4th earliest date recorded in 96 years of the event.

 

Negative deviations were found in the Southern Bering Sea area with St Paul Island (-3.8°F) and Cold Bay (-3.4°F) having the largest deviations; the previous month had the witnessed the greatest sea ice coverage in the Bering Sea since 1979, the point at which suitable satellite coverage began. Southeastern Alaska, while still seasonably above normal, reported the smallest positive deviations with Juneau (1.0°F) and Annette (0.5°F) and Yakutat (0.2°F). For greater details of the deviations from normal at the different stations, see the table below. It is interesting to note that the flip-flop in temperatures continued. November had temperatures far below the expected values, while December was much higher than normal, and for most stations, substantially warmer than those of November. January was much colder and many new low temperature records were observed, while in February, the temperature for most of Alaska was above normal, with only the first and last days of the month being seasonably below normal. Then, March was colder than normal again, and for most stations temperatures were lower than in February. Finally in April temperatures were once again above the expected normal.

 

 

Station

Temperature

Observed
(°F)

Normal
(°F)

Delta
(°F)

Anchorage

38.8

36.8

2.0

Annette

44.7

44.2

0.5

Barrow

4.6

1.8

2.8

Bethel

24.9

26.9

-2.0

Bettles

28.3

23.3

5.0

Big Delta

37.7

32.2

5.5

Cold Bay

30.6

34.0

-3.4

Fairbanks

36.9

32.5

4.4

Gulkana

35.4

31.8

3.6

Homer

36.0

37.0

-1.0

Juneau

41.8

40.8

1.0

King Salmon

35.4

33.7

1.7

Kodiak

39.5

37.6

1.9

Kotzebue

14.3

13.3

1.0

McGrath

32.9

29.7

3.2

Nome

20.4

20.5

-0.1

St. Paul Island

25.4

29.2

-3.8

Talkeetna

37.8

35.9

1.9

Valdez

40.2

38.1

2.1

Yakutat

38.0

37.8

0.2

 

 

Quite a number of new daily temperature records were set in April. However, only two were new low records, and both were set in St. Paul early in the month. Review Table 2 for more details. The records are indicative of a warmer than normal month for much of Alaska, and the colder temperatures for the Bering Sea area.

 

 

 

Temperature Records

Date

Station

Element

New
Record

Old
Record

Year of
old Record

04/02/12

St. Paul

Low Temperature

0

3

1995

04/05/12

St. Paul

Low Temperature

-4

-3

1976

04/08/12

Annette

High Temperature

62

60

1959

04/09/12

Klawock

High Temperature

63

54

1987

04/11/12

Valdez

High Temperature

52

52

2003

04/12/12

Juneau

High Temperature

62

57

2003

04/12/12

McGrath

High Temperature

50

50

1997

04/12/12

Skagway Airport

High Temperature

63

60

1984

04/13/12

Big Delta

High Temperature

52

52

1978

04/13/12

Skagway Airport

High Temperature

63

60

1984

04/13/12

Valdez

High Temperature

52

52

1978

04/15/12

Big Delta

High Temperature

56

55

1965

04/15/12

McGrath

High Temperature

53

52

1990

04/16/12

Fairbanks

High Temperature

61

59

1993

04/16/12

Juneau

High Temperature

57

56

2010

04/16/12

McGrath

High Temperature

56

55

1998

04/17/12

Bettles

High Temperature

51

51

1993

04/17/12

McGrath

High Temperature

56

56

1993

04/19/16

Juneau

High Temperature

59

59

1993

04/21/16

Kodiak

High Temperature

56

55

1936

04/21/16

Valdez

High Temperature

58

54

1978

04/26/16

Kodiak

High Temperature

59

57

1990

04/28/16

Cold Bay

High Temperature

49

49

2003

04/28/16

King Salmon

High Temperature

61

58

2005

 

 

Daily temperature ranges and precipitation for Juneau for April 2012. Note the three high temperature record events and one precipitation record event that occurred during the month.

 

 

Precipitation

Precipitation was below normal for 16 of the 20 stations. Bettles with just 0.10" or 17% of normal, and Fairbanks with 0.07" or 23% of normal reported the greatest deviations. On the other side of the spectrum was Cold Bay, recording 183% of the mean value, or 4.43" of the expected 2.42". The mean value for the 20 stations was substantially below normal with a negative deviation of -35%. As for the temperature, the precipitation deviations for the different station are given in the table below:

 

 

Station

Precipitation

Observed
(in)

Normal
(in)

Delta
(in)

(%)

Delta
(%)

Anchorage

0.50

0.47

0.03

106%

6%

Annette

4.52

6.77

-2.25

67%

-33%

Barrow

0.17

0.16

0.01

106%

6%

Bethel

0.42

0.74

-0.32

57%

-43%

Bettles

0.10

0.60

-0.50

17%

-83%

Big Delta

0.11

0.23

-0.12

48%

-52%

Cold Bay

4.43

2.42

2.01

183%

83%

Fairbanks

0.07

0.31

-0.24

23%

-77%

Gulkana

0.15

0.24

-0.09

63%

-38%

Homer

0.72

1.07

-0.35

67%

-33%

Juneau

1.68

2.94

-1.26

57%

-43%

King Salmon

0.56

0.97

-0.41

58%

-42%

Kodiak

3.99

5.81

-1.82

69%

-31%

Kotzebue

0.20

0.54

-0.34

37%

-63%

McGrath

0.43

0.74

-0.31

58%

-42%

Nome

0.33

0.76

-0.43

43%

-57%

St. Paul Island

1.29

1.08

0.21

119%

19%

Talkeetna

0.51

1.29

-0.78

40%

-60%

Valdez

1.59

3.42

-1.83

46%

-54%

Yakutat

3.88

9.19

-5.31

42%

-58%

 

 

There were a few new daily records, both for precipitation and snowfall (both in inches), and are summarized in Table 4.

 

 

 

Precipitation Records

Date

Station

Element

New
Record

Old
Record

Year of
old Record

04/05/12

Cold Bay

Snowfall

2.5

1.9

1972

04/05/12

King Salmon

Snowfall

3.2

2.8

1990

04/05/12

Kotzebue

Precipitation

0.2

0.09

1968

04/06/12

Valdez

Precipitation

0.5

0.31

1986

04/08/12

Cold Bay

Precipitation

1.26

0.45

1959

04/29/12

Juneau

Precipitation

0.67

0.52

1996

04/29/12

St. Paul

Snowfall

1.6

1

1980

04/29/12

Yakutat

Precipitation

1.69

1.47

1975

 

 

On the 9th of April, the first geese were observed at Creamers Field in Fairbanks, a sure sign of spring. Then on the 17th, the road into Denali Park was cleared to the Teklanika rest area, some 30 miles into the park and opened to the public. The winter snowfall mop-up continued when an avalanche was finally cleared from a road in the Cordova area on the 18th. The 20th marked the first day of no measureable snow on the ground at the Fairbanks airport. Then around the 20th of April some flooding was observed in the Salcha area, a nearly annual event. Ice jams on the Tanana River on the 28th, just downstream from Manley Hot Springs, raised the water substantially and roughly 20 cabins and houses were flooded. The water level reached its highest level since 1993.

 

 

This information consists of preliminary climatological data compiled by the Alaska Climate Research Center, Geophysical Institute, University of Alaska Fairbanks. This summary is based on the 20 first order stations in Alaska operated by the National Weather Service. Extreme events of other stations are also mentioned. It should be noted that the new climate normals for the time period of 1981-2010 are applied for the calculations of the deviations, and they can be slightly different from the old normals (1971-2000), which were in use up until end of July 2011.