August 2011 Alaska weather summary released

By: 
Public Relations
September 12, 2011

For most of Alaska, temperatures were below normal this August. Large negative deviations greater than minus 2 degrees Fahrenheit were observed in Juneau (minus 2.8 degrees Fahrenheit), King Salmon (minus 2.5 degrees Fahrenheit) and Nome (minus 2.1 degrees Fahrenheit). Like the previous month, Barrow reported the largest positive deviation with plus 3.2 degrees Fahrenheit. The only other positive deviation of our eight-city summary was Fairbanks with plus 1.1 degree Fahrenheit. 

 

Precipitation for most weather stations was above normal, with a maximum deviation reported in Southeast at nearly twice the expected amount. The combination of below normal temperatures and above normal precipitation observed over most stations for the summer suppressed wild fires. Over the summer, less than 300,000 acres burned, about one-third of the mean amount for the last 60 years. 

 

The new climate normals, established by NOAA’s National Climatic Data Center for the time period of 1981-2010, became effective on August 1, 2011. These new normals replace the previous normals that were three-decade averages of climatological variables between 1971-2000. 

 

In August, Fairbanks’ average temperature was 57.2 degrees Fahrenheit, 1.1 degree above the long-term mean for August. The high temperature for the month was 76 degrees on August 4. The lowest temperature of the month, 40 degrees, was observed August 8. In general, the whole month was close to normal and no new daily records, whether it be maxima or minima, was observed during August in Fairbanks. 

 

Precipitation in August was 1.6 inches, 15 percent below the expected value. However, the month was cloudy (mean sky cover 70 percent) and on 21 days some precipitation was recorded. Wind speed averaged 3.8 mph. The highest gust was 28 mph August 19.

 

Big Delta reported a mean temperature of 53.6 degrees Fahrenheit in August. This was 1.2 degrees below the long-term mean temperature for August. The high temperature of the month, 70 degrees, was observed August 4. The month’s low temperature occurred August 8. It was only 34 degrees Fahrenheit. While this latter value came close to the absolute minimum of 33 degrees observed in 1969, no new extreme temperatures were observed during August. 

 

Precipitation totaled 1.44 inches, 24 percent below the expected amount. No new precipitations records were set during the month.

 

In Juneau, the average temperature was 53.1 degrees Fahrenheit in August. This was minus 2.8 degrees below normal for the month. It is notable that both the maximum temperature (66 degrees) and the minimum temperatures (40 degrees) for the month occurred on the same day – August 13. 

 

Precipitation totaled 10.72 inches, which is a significant 87 percent above normal. This came close to the maximum amount ever measured for the month of August, which was 11.02 inches set in 2006. Explicitly, this was the fourth wettest August on record. On August 15, 16 and 20, new record precipitation totals were logged. August 16 and 20 recorded identical values of 1.38 inches. A number of other stations in the Southeast also reported record rainfalls on the 20th. On August 28, the record precipitation, which was in place since 1988, was tied with 0.76 inches. Sky cover averaged 90 percent of the month, with 30 cloudy days and some rain occurring on 28 days of the month. Average wind speed at the Juneau International Airport was 7.1 mph, with a highest wind gust of 41 mph August 20.

 

Anchorage recorded an average temperature of 54.9 degrees Fahrenheit, 1.8 degrees below normal. During the whole month of August, the temperature never reached 70 degrees. The highest temperature occurred August 16. It was 68 degrees Fahrenheit. The month’s low, 41 degrees, was observed August 28. No temperature records were set during the month and the observed temperatures followed fairly close to the expected values. 

 

Precipitation was reported at 3.91 inches, which was 20 percent above the normal value. Mean monthly cloudiness was 80 percent and some precipitation was measured on 26 days of the month. The average monthly wind speed was 5.7 mph. A 40-mph-gust was recorded on the August 7.

 

In August, Nome reported a mean monthly temperature of 48 degrees Fahrenheit, a negative deviation of 2.1 degrees from the long-term mean. The warmest monthly temperature was 70 degrees observed August 19. The coldest temperature was 30 degrees Fahrenheit with a light frost on the 28th of the month. 

 

Precipitation was high, totaling 4.36 inches, 35 percent above the expected amount. The rainfall on August 11 set a new record for the day at 1.21 inches. This surpassed the old record of 1.05 inches set in 1958. The average wind speed for the month was 7.7 mph and the highest gust observed was 37 mph on the 24th.

 

Barrow reported an average temperature in August of 42.1 degrees Fahrenheit. This was 3.2 degrees above normal and the highest positive deviation of the eight cities reviewed for this summary. The maximum temperature, 58 degrees Fahrenheit, occurred August 5. The lowest temperature, 33 degrees, was observed on August 25. It is somewhat remarkable that no frost occurred during the month of August. In general, the temperatures during most of the month were close to normal. There were exceptions at the beginning and the end of August when above normal temperatures occurred. No new records were observed during the month.

 

Precipitation in Barrow totaled 0.82 inches, 22 percent below the normal value. No snow was observed during the month. The mean monthly wind speed was 11.4 mph and a gust of 37 mph occurred August 4.

 

King Salmon reported an average temperature of 52.1 degrees Fahrenheit, a substantial 2.5 degrees below the long-term mean. The high temperature for August was 71 degrees, recorded on the 17th. The lowest temperature for the month was 33 degrees August 23. This latter value represents a new record low for that specific day. The old record had been 34 degrees set in 1969.

 

The precipitation total was measured as 3.99 inches, surpassing the normal value of 2.95 inches. On 25 days of August at least some rain was recorded. Average wind speed was 7.4 mph and the highest gust was recorded at 36 mph on the 19th

 

Ketchikan’s average temperature of 56.8 degrees Fahrenheit in August was 1.2 degrees below the long-term mean. The highest temperature of the month, 71 degrees, occurred August 9. The low temperature, 44 degrees, occurred August 25. While the mean monthly temperature was somewhat below the expected value, the daily temperature ranges followed fairly close to the long-term means. No new temperature extremes were observed.

 

Monthly precipitation was measured at 17.73 inches, nearly twice the expected amount of 9.81 inches. Remarkable were the precipitation events of August 20 and 23, with totals of 4.63 inches and 3.8 inches, respectively. This precipitation set new records for the days. Many other stations in Southeast also reported record rainfalls on the 20th. 

 

This information consists of preliminary climatological data compiled by the Alaska Climate Research Center, Geophysical Institute, University of Alaska Fairbanks. For more information on weather and climatology, contact the center at 474-7885 or visit the center web site at http://akclimate.org. Please report any errors to webmaster@akclimate.org.