Wednesday, August 24, 2011

Arctic Sea Ice Update

August 16, 2011: Arctic sea ice at the crossroads
After a period of slow melt from late July through early August, Arctic ice extent is again declining at a brisk pace, but remains higher than for 2007, the record low year. Data also indicate continued thinning of the ice. With about a month left in the sea ice melt season, the amount of further ice loss will depend mostly on weather patterns.

Graph: Arctic sea ice extent on August 14, 2011 was 5.56 million square kilometers (2.15 million square miles). Map: The orange line shows the 1979 to 2000 median extent for that day. The black cross indicates the geographic North Pole. Sea Ice Index data.
—Credit: National Snow and Ice Data Center

Overview of conditions
As of August 14, 2011, Arctic sea ice extent was 5.56 million square kilometers (2.15 million square miles), 2.11 million square kilometers (815,000 square miles) below the 1979 to 2000 average for that day, and 220,000 square kilometers (84,900 square miles) above the extent on that day in 2007.

Sea ice is low across almost all of the Arctic, with the exception of some areas of the East Greenland Sea. It is exceptionally low in the Laptev and Kara Sea areas.

The southern route of the Northwest Passage, now appears to be free of sea ice according to imagery from the University of Bremen and the NSIDC Multisensor Analyzed Sea Ice Extent (MASIE) analyses. However, U.S. National Ice Center analyses indicate that there may be up to 20% ice concentration remaining in some parts of the route .

Tuesday, August 16, 2011

Winter 2011-12 El Niño & La Niña Outlook

Winter 2011-12 El Niño & La Niña Outlook

Climatologists know that El Niño and La Niña can have a Strong influence on our winter weather patterns in North America. So what is it looking like for this coming Winter?

Most of the set of dynamical and statistical models (see graph) predict neutral ENSO (El Niño Southern Oscillation) conditions from the July-September 2011 season currently in progress, through the early part of 2012.

Current predictions and observations indicate a probability of 26% for La Niña conditions for the November 2011-January 2012 time period, with the probability for El Niño conditions at 14% for the November 2011-January 2012. The probability of Neutral or "Nada Nino" (my term) conditions from November through January is the largest at 60% .

July 2011 Global Temperatures 7th Warmest on Record

July 2011 Global Highlights (from NCDC)
•The combined global land and ocean average surface temperature for July 2011 was the seventh warmest on record (out of 132 years of data) , at 16.37°C (61.43°F), which is 0.57°C (1.03°F) above the 20th century average of 15.8°C (60.4°F).

•The July worldwide land surface temperature was 0.84°C (1.51°F) above the 20th century average of 14.3°C (57.8°F)—the fifth warmest July on record.

•The worldwide ocean surface temperature was 0.47°C (0.85°F) above the 20th century average of 16.4°C (61.5°F)—the 11th warmest July on record.

•Neither El Niño nor La Niña conditions were present during July 2011. According to NOAA's Climate Prediction Center, ENSO-neutral conditions are expected to continue into the Northern Hemisphere fall 2011.

•For the year-to-date, the global combined land and ocean surface temperature of 14.31°C (57.82°F) was the 11th warmest January–July period on record. This value is 0.51°C (0.92°F) above the 20th century average.


Tuesday, August 9, 2011

July 2011: 4th Warmest on Record for the U.S.

NOAA: Heat wave leads to fourth warmest July on record for the U.S.

Persistent, scorching heat in the central and eastern regions of the United States shattered long-standing daily and monthly temperature records last month, making it the fourth warmest July on record nationally, according to scientists at NOAA’s National Climatic Data Center. The heat exacerbated drought conditions, resulting in the largest “exceptional” drought footprint in the 12-year history of the U.S. Drought Monitor. “Exceptional” is the most severe category of drought on the drought monitor scale. Drought conditions at several locations in the South region are not as long lived, but are as dry, or drier, than the historic droughts of the 1930s and 1950s.

The average U.S. temperature in July was 77.0 degrees F, which is 2.7 degrees F above the long-term (1901-2000) average. Precipitation, averaged across the nation, was 2.46 inches. This was 0.32 inch below the long-term average, with large variability between regions. This monthly analysis, based on records dating back to 1895, is part of the suite of climate services NOAA provides.

Tuesday, August 2, 2011

Which month normally has the hottest temperature in Lincoln

Although the greatest amount of daylight and possible solar energy occurs around June 21 each year, the hottest temperatures typically occur at least a month later. Climatologically, the hottest week is normally the last week in July. Sometimes the hottest temperatures are delayed even further into the summer and occur in August.

The hottest Summer 2011 temperature was 104 F on August 1.

Here are the hottest days, each year, for the past 10 years, with the hottest day occurring in July 5 times and August 5 times:

2010 August 12
2009 August 8
2008 August 3
2007 August 13
2006 July 19
2005 July 23
2004 August 3
2003 July 17
2002 July 21
2001 July 6

Looking back over the past 30 years (1981-2010), the hottest day occurred
in May 1 time
in June 2 times
in July 14 times
in August 12 times
in September 1 time

all of the Lincoln hottest temperatures for each year can be found at our "Heat Wave" page:

Link to Heat Wave Page