Friday, July 18, 2014

State of the Climate Update

Headline:  2013 State of the Climate Report Released

Update from Ken Dewey, Applied Climate Science, School of Natural Resources, UNL.

From NOAA:  On July 17, the National Oceanic and Atmospheric Administration and the American Meteorological Society released the 2013 State of the Climate report. The report was led by editors from NOAA's National Climatic Data Center.

The report, a 24-year tradition encompassing the work of 425 authors from 57 countries, uses dozens of climate indicators to track patterns, changes, and trends of the global climate system. These indicators often reflect many thousands of measurements from multiple independent data sets. The report also details cases of unusual and extreme regional events, such as Super Typhoon Haiyan, which devastated portions of Southeast Asia in November 2013.

 The following image does NOT have any links.  It does list the various topics found in the report.

Thursday, July 17, 2014

June 2014 Statewide Rankings

The Contiguous U.S. had its 6th wettest and 33rd warmest (88th coldest) June on record (120 years of data, 1895-2014).

Nebraska had near normal average June temperatures but a top 5 wettest June on record. Much of the upper Midwest and Plains had a very wet month during June 2014.  The drought in the SW U.S. continued unabated.

 MAPS: See the statewide temperature and precipitation rankings maps below the text.

  • Climate Highlights — June
  • The average temperature for the contiguous U.S. during June was 69.6°F, 1.1°F above the 20th century average, ranking as the 33rd warmest June in the 120-year period of record. The average maximum (daytime) June temperature for the contiguous U.S. was 81.8°F, 0.4°F above the 20th century average, while the average minimum (nighttime) June temperature was 57.4°F, 1.7°F above the 20th century average, tying as the 10th warmest June minimum temperature.
  • Above-average June temperatures were observed along the East Coast and into the Midwest. The Southwest was also warmer than average, where Arizona and California both had their 11th warmest June on record. No state had a top 10 warm June.
  • Near-average June temperatures were observed from the central Gulf Coast, through the Central Plains, and into the Northwest. Below-average temperatures were observed in the Northern Rockies and parts of the Northern Plains. No state had a top 10 cool June.
  • Interestingly, in much of the Lower Mississippi Valley and mid-South, afternoon temperatures were below average, while nighttime temperatures were much above average. This likely reflects a relatively wet and cloudy summer month acting to moderate both afternoon and overnight temperatures.
  • The June national precipitation total was 3.62 inches, 0.69 inch above the 20th century average, marking the sixth wettest June on record, and the wettest since 1989.
  • A significant portion of the contiguous U.S. — parts of the Northeast, Southeast, Midwest, and the Great Plains — had above-average precipitation during June. Eight states had one of their 10 wettest Junes on record, with Minnesota being record wet for the month. The 7.75 inches of precipitation averaged across Minnesota was 3.64 inches above the 20th century average, marking the wettest month of any month for the state, surpassing July 1897 and June 1914 when 7.32 inches of precipitation was observed. In Canton, South Dakota, 19.65 inches of precipitation fell during June, setting a new record among all months for any location in the state, according to the South Dakota State Climatologist.
  • Below-average June precipitation was observed in the Southwest, across parts of the coastal Southeast, and southern New England. Arizona tied its third driest June on record, with 0.01 inch of precipitation, 0.28 inch below the 20th century average; only June 1916 and 1951 were drier.
  • Alaska was much wetter than average during June with a statewide precipitation total 53 percent above the 1971-2000 average, the second wettest June for the state. The wettest June occurred in 1980 when the monthly precipitation was 74 percent above average. Juneau and Fairbanks each had their wettest June on record, while Anchorage had its second wettest.
  • According to the July 1 U.S. Drought Monitor report, 34.0 percent of the contiguous U.S. was in drought, down about 3.3 percent compared to the beginning of June.
    • Beneficial rain improved drought conditions by one to three categories across parts of the Midwest and the Central and Southern Plains. Nebraska, which had its fourth wettest June, saw dramatic drought improvement.
    • Warm and dry conditions in parts of the West led to scattered locations experiencing worsening drought conditions. In California, the percent area of the state experiencing exceptional drought, the worst category, expanded to 36.5 percent, up over 11 percent since early June. In the East, abnormally dry conditions expanded in the Tennessee River Valley and southern New England.
  • Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand during June was 33 percent above average and the 25th highest in the 1895-2014 period of record.
  • There were more record cool high temperature records (676) than record warm high temperature records (391), but warm nighttime temperatures dominated with more record warm low temperatures (1257) than record cold low temperatures (344). When aggregated together, there were more than one and a half times as many record warm daily highs and lows (1648) as record cold daily highs and lows (1020).

Monday, July 14, 2014

Lake Mead Drops to Record Low Elevation

Headline:  Persistent drought lowers Lake Mead to record low elevation.

Lake Mead at Hoover Dam, July 2014.
Photo © Ken Dewey, Applied Climate Science, SNR, UNL.
The red line labeled "A" shows the "bathtub ring", i.e., the height of the water when the Lake is at capacity. The red line with the label "B" shows the height of the water level on December 21, 2012. The red line with the label "C" shows the height of the water level on July 11, 2014 (1081.77 feet or 147.23 feet below capacity)..  
The white "bathtub ring" is the result of exposing rocks that were at one time under the water and collecting mineral deposits.  A clear glass, for example, dipped in water and then allowed to dry will have mineral deposit "spots" on the glass.

The Bureau of Reclamation noted that Lake Mead, the reservoir created by Hoover Dam, reached its lowest water level since the lake’s initial filling in the 1930s.

Lake Mead elevation as of July 11, 2014 was 1081.77 feet, which is 147.23 feet below capacity.
Lake Mead was dedicated in 1935 and began filling up that year. Note that the elevation in July 1935 and 1936 (see table: Table of historical Lake Mead Levels.) was only 928.40 feet and 1020.40 feet. Because Lake Mead was in the process of filling up in 1935-36, the actual record minimum elevation following the initial fill up of the Lake occurred on July 11, 2014. The level of the lake could continue to fall below the July 11, 2014 elevations.
It took 19 years after the 1964 low point for Lake Mead to fill up again.

For more information, check out our full report at:  Lake Mead 2014

Lake Mead at Hoover Dam, July 2014.
Photo © Ken Dewey, Applied Climate Science, SNR, UNL.