New insights into predicting future droughts in California: Natural cycles, sea surface temperatures found to be main drivers in ongoing event

According to a new NOAA-sponsored study, natural oceanic and atmospheric patterns are the primary drivers behind California's ongoing drought. A high pressure ridge off the West Coast (typical of historic droughts) prevailed for three winters, blocking important wet season storms, with ocean surface temperature patterns making such a ridge much more likely. Typically, the winter season in California provides the state with a majority of its annual snow and rainfall that replenish water supplies for communities and ecosystems.

Further studies on these oceanic conditions and their effect on California's climate may lead to advances in drought early warning that can help water managers and major industries better prepare for lengthy dry spells in the future.

"It's important to note that California's drought, while extreme, is not an uncommon occurrence for the state. In fact, multi-year droughts appear regularly in the state's climate record, and it's a safe bet that a similar event will happen again. Thus, preparedness is key," said Richard Seager, report lead author and professor with Columbia University's Lamont Doherty Earth Observatory.

This report builds on earlier studies, published in September in the Bulletin of the American Meteorological Society, which found no conclusive evidence linking human-caused climate change and the California drought. The current study notes that the atmospheric ridge over the North Pacific, which has resulted in decreased rain and snowfall since 2011, is almost opposite to what models project to result from human-induced climate change. The report illustrates that mid-winter precipitation is actually projected to increase due to human-induced climate change over most of the state, though warming temperatures may sap much of those benefits for water resources overall, while only spring precipitation is projected to decrease.

The report makes clear that to provide improved drought forecasts for California, scientists will need to fully understand the links between sea surface temperature variations and winter precipitation over the state, discover how these ocean variations are generated, and better characterize their predictability.

This report contributes to a growing field of science-climate attribution-where teams of scientists aim to identify the sources of observed climate and weather patterns.

"There is immense value in examining the causes of this drought from multiple scientific viewpoints," said Marty Hoerling, report co-author and researcher with NOAA's Earth System Research Laboratory. "It's paramount that we use our collective ability to provide communities and businesses with the environmental intelligence they need to make decisions concerning water resources, which are becoming increasingly strained."

To view the report, visit:?http://cpo.noaa.gov/MAPP/californiadroughtreport.

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Get accustomed to prolonged high temperatures: Extreme El Nino occasions to double

Extreme weather occasions fueled by abnormally strong El Ninos, like the 1983 heatwave that brought towards the Ash Wednesday bushfires around australia, will probably double in number as our world warms up.

An worldwide team of researchers from organizations such as the ARC Center of Excellence for Climate System Science (CoECSS), the united states National Oceanic and Atmospheric Administration and CSIRO, released their findings within the journal Character Global Warming.

"We presently receive an abnormally strong El Ni?o event every two decades. Our studies have shown this can double to 1 event every ten years,Inch stated co-author, Dr Agus Santoso of CoECSS.

"El Nino occasions really are a multi-dimensional problem, and just now shall we be beginning to know better the way they react to climatic change," stated Dr Santoso. Extreme El Ni?o occasions develop in a different way from standard El Ninos, which first come in the western Off-shore. Extreme El Nino's occur when ocean surface temps exceeding 28?C develop within the normally cold and dry eastern equatorial Gulf Of Mexico. This different place for the foundation from the temperature

increase causes massive alterations in global rain fall designs.

"The issue of methods climatic change can change the regularity of utmost El Ni?o occasions has challenged researchers in excess of two decades,Inch stated co-author Dr Mike McPhaden people National Oceanic and Atmospheric Administration.

"These studies may be the first comprehensive study of the problem to create robust and convincing results," stated Dr McPhaden.

The impacts of utmost El Ni?o occasions include every region around the world.

The 1997-98 event alone triggered $35-45 US billion in damage and stated an believed 23,000 human lives worldwide.

"Throughout a serious El Ni?o event nations within the western Off-shore, for example Australia and Indonesia, experienced devastating droughts and wild fires, while catastrophic surges happened within the eastern equatorial region of Ecuador and northern Peru," stated lead author, CSIRO's Dr Wenju Cai

Around Australia, the drought and dry conditions caused through the 1982-83 extreme El Ni?o preconditioned the Ash Wednesday Bushfire in southeast Australia, resulting in 75 deaths.

To attain their results, they examined 20 climate appliances consistently simulate major rain fall reorganization throughout extreme El Ni?o occasions. They found a considerable rise in occasions in the present-day with the next a century because the eastern Gulf Of Mexico warmed as a result of climatic change.

"This latest research according to rain fall designs, indicates that extreme El Ni?o occasions will probably double in frequency because the world warms up resulting in direct impacts on extreme weather occasions worldwide."

"For Australia, this might mean summer time prolonged high temperatures, like this lately familiar with the south-east of the nation, might get yet another boost when they coincide with extreme El Ninos," stated co-author, Professor Matthew England from CoECSS.

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Global July temperatures sixth highest on record

Note: The data presented in this report are preliminary. Ranks and anomalies may change as more complete data are received and processed. Effective September 2012, the GHCN-M version 3.2.0 dataset of monthly mean temperature replaced the GHCN-M version 3.1.0 monthly mean temperature dataset. Beginning with the August 2012 Global monthly State of the Climate Report, released on September 17, 2012, GHCN-M version 3.2.0 is used for NCDC climate monitoring activities, including calculation of global land surface temperature anomalies and trends. For more information about this newest version, please see the GHCN-M version 3.2.0 Technical Report.

*The GHCN-M version 3.1.0 Technical Report was revised on September 5, 2012 to accurately reflect the changes incorporated in that version. Previously that report incorrectly included discussion of changes to the Pairwise Homogeneity Algorithm (PHA). Changes to the PHA are included in version 3.2.0 and described in the version 3.2.0 Technical Report. Please see the Frequently Asked Questions to learn more about this update.

An omission in processing a correction algorithm led to some small errors on the Global Historical Climatology Network-Monthly dataset (GHCN-M v3.2.0). This led to small errors in the reported land surface temperatures in the October, November, December and Annual U.S. and global climate reports. On February 14, 2013, NCDC fixed this error in its software, included an additional improvement (described below), and implemented both changes as GHCN-M version 3.2.1. With this update to GHCN-M, the Merged Land and Ocean Surface Temperature dataset also is subsequently revised as MLOST version 3.5.3.

The net result of this new version of GHCN-M reveals very small changes in temperature and ranks. The 2012 U.S. temperature is 0.01°F higher than reported in early January, but still remains approximately 1.0°F warmer than the next warmest year, and approximately 3.25°F warmer than the 20th century average. The U.S. annual time series from version 3.2.1 is almost identical to the series from version 3.2.0 and that the 1895-2012 annual temperature trend remains 0.13°F/decade. The trend for certain calendar months changed more than others (discussed below). For the globe, ranks of individual years changed in some instances by a few positions, but global land temperature trends changed no more than 0.01°C/century for any month since 1880.

NCDC uses two correction processes to remove inhomogeneities associated with factors unrelated to climate such as changes in observer practices, instrumentation, and changes in station location and environment that have occurred through time. The first correction for time of observation changes in the United States was inadvertently disabled during late 2012. That algorithm provides for a physically based correction for observing time changes based on station history information. NCDC also routinely runs a .pairwise correction. algorithm that addresses such issues, but in an indirect manner. It successfully corrected for many of the time of observation issues, which minimized the effect of this processing omission.

The version 3.2.1 release also includes the use of updated data to improve quality control and correction processes of other U.S. stations and neighboring stations in Canada and Mexico.

Compared to analyses released in January 2013, the trend for certain calendar months has changed more than others. This effect is related to the seasonal nature of the reintroduced time-of-observation correction. Trends in U.S. winter temperature are higher while trends in summer temperatures are lower. For the globe, ranks of individual years changed in some instances by a few positions, but global temperature trends changed no more than 0.01°C/century for any month since 1880.

More complete information about this issue is available at this supplemental page.

NCDC will not update the static reports from October through December 2012 and the 2012 U.S and Global annual reports, but will use the current dataset (GHCN-M v. 3.2.1 and MLOST v. 3.5.3) for the January 2013 report and other comparisons to previous months and years.

The combined average temperature over global land and ocean surfaces for July 2013 was the sixth highest on record, at 0.61°C (1.10°F) above the 20th century average of 15.8°C (60.4°F). The global land surface temperature was 0.78°C (1.40°F) above the 20th century average of 14.3°C (57.8°F), marking the eighth warmest July on record. For the ocean, the July global sea surface temperature was 0.54°C (0.97°F) above the 20th century average of 16.4°C (61.5°F), the fifth warmest July on record. The combined global land and ocean average surface temperature for the January–July period (year-to-date) was 0.59°C (1.06°F) above the 20th century average of 13.8°C (56.9°F), tying with 2003 as the sixth warmest such period on record.

Temperature anomalies and percentiles are shown on the gridded maps below. The anomaly map on the left is a product of a merged land surface temperature (Global Historical Climatology Network, GHCN) and sea surface temperature (ERSST.v3b) anomaly analysis developed by Smith et al. (2008). Temperature anomalies for land and ocean are analyzed separately and then merged to form the global analysis. For more information, please visit NCDC's Global Surface Temperature Anomalies page. The July 2013 Global State of the Climate report includes percentile maps that complement the information provided by the anomaly maps. These maps on the right provide additional information by placing the temperature anomaly observed for a specific place and time period into historical perspective, showing how the most current month, season, or year-to-date compares with the past.

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In the atmosphere, 500-millibar height pressure anomalies correlate well with temperatures at the Earth's surface. The average position of the upper-level ridges of high pressure and troughs of low pressure—depicted by positive and negative 500-millibar height anomalies on the July 2013 map—is generally reflected by areas of positive and negative temperature anomalies at the surface, respectively.

The average global temperature across the world's land and ocean surfaces for July 2013 was 0.61°C (1.10°F) above the 20th century average of 15.8°C (60.4°F), making this the sixth warmest July since records began in 1880. This marks the 341st consecutive month, since February 1985, that the global monthly temperature has been higher than the long-term average for its respective month. Nine of the ten warmest Julys on record have occurred since the beginning of the 21st century (July 1998 is currently the record warmest).

Most of the world's land surfaces were warmer than average during July, with northern South America, the western and northeastern United States, much of Africa, western and central Europe, parts of southern Asia, and most of Australia classified as much warmer than average, as indicated by the Land and Ocean Temperature Percentiles map above. Parts of the central and southeastern United States, small regions across northern Canada, eastern Greenland, and parts of Mongolia and eastern Russia were cooler than average. Far northwestern Canada and part of the eastern United States were much cooler than their long-term averages. Overall, the globally-averaged land surface temperature was the eighth warmest July on record, at 0.78°C (1.40°F) above the 20th century average. The Northern Hemisphere tied with 2008 as 10th warmest, while the Southern Hemisphere was second highest for July, behind only 1998.

Select national information is highlighted below:
The national July temperature for Australia was 1.46°C (2.63°F) above the 1961–1990 average, marking the third warmest July since national records began in 1901. The July maximum temperature was the third highest at 1.52°C (2.74°) above average, while the minimum temperature was eighth highest. With the exception of Western Australia, every state and territory had an average July temperature that ranked among their seven highest on record. Tasmania reported a record high state-wide maximum temperature that was 1.28°C (2.30°F) higher than average, breaking the previous record set in 1950 and tied in 1993. No state or territory had maximum or minimum temperatures below their long-term averages.
New Zealand observed its fourth warmest July since national records began in 1909, with a temperature that was 1.2°C (2.2°F) higher than the 1971–2000 average. Many locations around Otago and Canterbury on the South Island had a record warm July.
Spain had its fifth warmest July since national records began in 1961, with a temperature that was 1.6°C (2.9°F) above the 1971–2000 average. The northern regions observed the highest anomalies, with some areas up to 3°C (5°F) above average.
It was the third warmest July across the United Kingdom since records began in 1910, at 1.9°C (3.4°F) above the 1981–2010 average. The "most notable heat wave since 2006" contributed to the warmth, according to the UK Met Office. Provisionally, it was the warmest July and second warmest month of any month on record (behind August 1995) for Northern Ireland.
With records dating back to 1767, Austria reported its second warmest July, tied with July 1983 and behind only 2006, with the nationally-averaged temperature 2.2°C (4.0°F) above the 1981–2010 average. Upper Austria and Salzburg each set new state maximum temperatures on July 28th.
The average July temperature across South Korea was the fourth warmest in the country's 41-year period of record, at 1.8°C (3.2°F) above the 1981–2010 average. The July minimum temperature was second highest on record for the month, at 2.1°C (3.8°F) above average.
July was warmer than average across nearly all of Japan. According to the Japan Meteorological Agency, Western Japan was significantly warmer than average, with a regionally-averaged July temperature that was 1.6°C (2.9°F) above the 1981–2010 average.

The globally-averaged ocean temperature was the fifth highest for July in the 134-year period of record, at 0.54°C (0.97°F) above the 20th century average. This marks the warmest July for the oceans since July 2009, when the last El Niño phase on record was beginning. During July 2013, conditions in the eastern and equatorial Pacific Ocean, where ENSO conditions are monitored via sea surface temperature observations, remained ENSO neutral, with near-average sea surface temperatures across the central and east-central equatorial Pacific and below-average sea surface temperatures in the eastern equatorial Pacific. Neutral conditions, with some temperature variation within the defined range (less than plus or minus 0.5°C / 0.9°F of average), have persisted since spring 2012. According to NOAA's Climate Prediction Center, ENSO neutral conditions are expected to continue into the Northern Hemisphere fall 2013. In other parts of the global oceans, many regions were much warmer than average, with part of the northeastern Atlantic off the coast of North America, sections of the southern Indian Ocean, and various regions in the western Pacific observing record warmth, as indicated on the Land and Ocean Temperature Percentiles map above. The far eastern equatorial Pacific Ocean off the coast of northern South America was the only region of the oceans that was much cooler than average for the month. Images of sea surface temperature conditions are available for all weeks during 2013 from the weekly SST page.

JulyAnomalyRank
(out of 134 years)Records

The most current data may be accessed via the Global Surface Temperature Anomalies page.

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With ENSO-neutral conditions present across the central and eastern equatorial Pacific Ocean for the entire period, the globally-averaged combined land and ocean temperature for the first seven months of 2013 (January–July) was 0.59°C (1.06°F) higher than the 20th century average, tying with 2003 as the sixth warmest such period on record. The global land surface temperature was also the sixth warmest on record. The Northern Hemisphere land areas were eighth warmest on average, while the Southern Hemisphere land was third warmest. In this region, much of Australia, along with part of southern Chile and central Namibia, were record warm, as indicated by the Land & Ocean Temperature Percentiles map above. Around the globe, only land surfaces across much of the United Kingdom and parts the central and southeastern United States were cooler than average for the January–July period. For the global oceans, the average January–July temperature was 0.45°C (0.81°F) above average, the eighth warmest such period on record. It was much warmer than average across the equatorial waters of the Atlantic, Indian, and western Pacific Oceans, along with waters surrounding most of Australia and the far northeastern Atlantic extending into the Arctic Seas.

January–JulyAnomalyRank
(out of 134 years)Records

The most current data may be accessed via the Global Surface Temperature Anomalies page.

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The maps below represent precipitation percent of normal (left) and precipitation percentiles (right) based on the GHCN dataset of land surface stations using a base period of 1961–1990. As is typical, precipitation anomalies during July 2013 varied significantly around the world. As indicated by the July precipitation percentiles map below, much of the eastern and central United States, India, southeastern Asia, and parts of eastern Russia were wetter or much wetter than average during July. Record dryness was present among regions that included part of central Europe, eastern Turkey, some scattered regions in west Africa, east central Brazil, and northern coastal Chile.

The United Kingdom had its driest July since 2006, with rainfall 82 percent of the 1981–2010 average. South-west England, East Anglia, and north-west Scotland were among the driest regions during the month.
Austria observed its driest July since national records began in 1858, with just 35 percent of the 1981–2010 average precipitation. Several regions only received 5 to 20 percent of their typical July rainfall.
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Peterson, T.C. and R.S. Vose, 1997: An Overview of the Global Historical Climatology Network Database. Bull. Amer. Meteorol. Soc., 78, 2837-2849.

Quayle, R.G., T.C. Peterson, A.N. Basist, and C. S. Godfrey, 1999: An operational near-real-time global temperature index. Geophys. Res. Lett., 26, 333-335.

Smith, T.M. and R.W. Reynolds, 2005: A global merged land air and sea surface temperature reconstruction based on historical observations (1880-1997), J. Clim., 18, 2021-2036.

Smith et al., 2008, Improvements to NOAA's Historical Merged Land-Ocean Surface Temperature Analysis (1880-2006), J. Climate., 21, 2283-2293.

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Snow, cold temperatures hamper U.S. tornado clean-up

WEST LIBERTY, Kentucky (Reuters) - A winter snowstorm and freezing temperatures on Monday hampered clean-up efforts in Indiana and Kentucky, the states hardest hit by a wave of powerful tornadoes and storms that killed dozens of people.

Three to five inches of snow fell in southern Indiana and north-central Kentucky, where recovery efforts were underway after at least 30 tornadoes ripped through the region on Friday, the National Weather Service said.

In West Liberty, Kentucky, emergency and security personnel, insurance inspectors, business owners and their employees gathered on the main street to assess the damage amid fears heavy wet snow would cause weakened buildings to collapse.

"Anything we can do to get back to normal business, (residents) will see that as a reason to believe we can recover," said Linda Oakley, who visited the damaged flower shop where she works, accompanied by her husband and firefighters.

The storms and tornadoes that struck the Midwest and South on Friday splintered blocks of homes and tossed around vehicles like toys. They came on the heels of severe weather that killed about a dozen people earlier in the week.

Officials said at least 39 people died in the latest wave of storms - 21 in Kentucky, 13 in Indiana, three in Ohio and one in Alabama. Georgia also reported a storm-related death.

Among the dead was a 14-month-old girl who succumbed to her injuries in a hospital in Louisville, Kentucky, on Sunday, two days after she was found in a field after a tornado hit the New Pekin, Indiana, area. Nearby lay the lifeless bodies of her parents and two siblings.

Kentucky Governor Steve Beshear said on Sunday the storm had caused at least $5.8 million in property damage. He has signed an executive order barring price gouging for food and other necessities.

HARD TO FORECAST

The destruction raised fears that 2012 would be another bad tornado season in the United States. A total of 550 deaths were blamed on twisters last year, the deadliest in nearly a century, according to the National Weather Service.

Greg Carbin, a meteorologist for the National Oceanic and Atmospheric Association's storm prediction center, said tornadoes often formed in March and April but added that it was hard to predict how severe the 2012 season would be.

Tornadoes typically occur in the United States between March and July, when warm, moist air meets cooler, dry air in the atmosphere. Some parts of the country experience a late tornado season in autumn.

"There's nothing that points at something above or below normal," Carbin said.

The weather in hard-hit areas, however, was expected to begin improving on Monday. The snowstorm was moving east and expected to drop up to three inches of snow in Virginia and in West Virginia before heading out to sea by evening.

"A high-pressure system will give clean-up crews tranquil weather through at least the middle part of the week," said Andy Mussoline, a meteorologist at AccuWeather.com. "A gradual warm-up supported by plenty of sunshine will follow."

(Editing By Ellen Wulfhorst and Paul Simao)

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