Category: Global Warming

bookmark_borderOh No Snow

Posted on by admin

BOZEMAN, Mont. – Warmer spring temperatures since 1980 are causing an estimated 20 percent loss of snow cover across the Rocky Mountains of western North America, according to new research from the U.S. Geological Survey.

The new study builds upon a previous USGS snowpack investigation which showed that, until the 1980s, the northern Rocky Mountains experienced large snowpacks when the central and southern Rockies experienced meager ones, and vice versa. Yet, since the 1980s, there have been simultaneous snowpack declines along the entire length of the Rocky Mountains, and unusually severe declines in the north.

The new study has teased apart and quantified the different influences of winter temperature, spring temperature, and precipitation on historic snowpack variations and trends in the region. To distinguish those varying influences, the researchers implemented a regional snow model that uses inputs of monthly temperature and precipitation data from 1895 to 2011.

“Each year we looked at temperature and precipitation variations and the amount of water contained within the snowpack as of April,” said USGS scientist Greg Pederson, the lead author of the study. “Snow deficits were consistent throughout the Rockies due to the lack of precipitation during the cool seasons during the 1930s – coinciding with the Dust Bowl era. From 1980 on, warmer spring temperatures melted snowpack throughout the Rockies early, regardless of winter precipitation. The model in turn shows temperature as the major driving factor in snowpack declines over the past thirty years.”

Runoff from Rocky Mountain winter snowpack accounts for 60 to 80 percent of the annual water supply for more than 70 million people living in the western U.S., and is influenced by factors such as the snowpack’s water content, known as snow water equivalent, and the timing of snowmelt.

The timing of snowmelt affects not only when water is available for crop irrigation and energy production from hydroelectric dams, but also the risk of regional floods and wildfires. Earlier and faster snowmelt could have repercussions for water supply, risk management, and ecosystem health in western watersheds.

Regional snowpack accumulation is highly sensitive to variations in both temperature and precipitation over time. Patterns and sources of these variations are difficult to discern due to complex mountain topography, the different influence of Pacific Ocean climate, like La Niña and El Niño, on winter precipitation in the northern versus southern and central Rockies, and the brevity and patchiness of detailed snow records.

In the study, the regional snow model used by Pederson and his USGS colleagues Julio Betancourt and Greg McCabe allows estimation of snow water and cover variability at different latitudes and elevations during the last century regardless of the absence of direct and long-term observations everywhere. Recent snowpack variations also were evaluated in the context of snowpack evidence from tree-rings, allowing the scientists to compare recent observations to measurements from the past 800 years.

McCabe, co-author of the study, explains that “recent springtime warming also reduced the extent of snow cover at low to middle elevations where temperature has had the greatest impact.”

“Both natural variability in temperature and anthropogenic warming have contributed to the recent snowpack decline, though disentangling their influences exactly remains elusive.” Betancourt said,

“Regardless of the ultimate causes, continuation of present snowpack trends in the Rocky Mountains will pose difficult challenges for watershed management and conventional water planning in the American West.”

The study, “Regional patterns and proximal causes of the recent snowpack decline in the Rocky Mountains,” is available from Geophysical Research Letters, a journal of the American Geophysical Union.

bookmark_borderCoastal Change: Hurricanes and Extreme Storm Hazards

Posted on by admin

Part of the Human Induced Climate Change Experiment

One of the goals of the USGS Coastal and Marine Geology Program is a national assessment of coastal change hazards. Hurricanes provide a powerful force that generates dangerous waves and currents capable of moving large amounts of sand, destroying buildings and infrastructure, and reshaping our nation’s coastline. Our research focuses on understanding the magnitude and variability of the impacts of hurricanes and extreme storms on the sandy beaches of the United States. The overall objective is to improve the capability to predict coastal change that results from severe storms. Such a capability will support management of coastal infrastructure, resources, and safety.

Hurricane Sandy Example

As Hurricane Sandy moved northward along the U.S. Atlantic coast in October 2012, U.S. Geological Survey scientists worked to determine where and how the storm’s waves and surge might dramatically reshape the beaches and dunes that stand between the storm and coastal developments. Through a complex modeling process that uses coastal elevations, wave forecasts, and potential storm surge, they predicted coastal change hazards, such as shoreline and dune erosion, that might be expected during a Sandy landfall.

Using the latest storm information available, USGS predicted the likelihood of a range of coastal change impacts within the region affected by the storm:

  • Dune erosion was very likely for the majority of the sandy beaches along the Maryland and Delaware coasts with widespread overwash also very likely in many areas.
  • Most of the New Jersey coast was very likely to experience extensive beach and dune erosion and many areas were very likely to overwash.
  • Along the south shore of Long Island, New York, the models predicted extensive beach and dune erosion as well as intermittent overwash.

Hurricane Sandy, the largest Atlantic hurricane on record, made landfall on October 30, 2012, and impacted a long swath of the Mid-Atlantic coastline. Many areas that had been hit by Hurricane Irene in August 2011 were again battered by strong waves and surge. The barrier islands were breached in a number of places and erosion of the beach and dunes occurred all along the Mid-Atlantic coast. This was the most destructive storm to impact this coastline since an extremely powerful nor’easter in December of 1992.

Following landfall, oblique aerial photography and lidar surveys of beach elevations were used to document the changes that occurred as a result of the storm. In addition, field measurements of the beaches and dunes were collected immediately after the storm. Comparisons of data collected before the storm show the nature, magnitude and spatial variability of the coastal response. These data will be used to further refine predictive models for storm-induced erosion.

Response Activities

Pre-landfall

Post-landfall (approx. 3-14 days)

bookmark_borderOzone Pollution Police

Posted on by admin

Ozone pollution is a significant problem and may be resulting in the deforestation of Earth.

The Environmental Defense Fund Wrote
This Is Your Final Warning: Enforcement Needed To Curtail Continued Pollution Problems

What makes you slow down more, a speeding ticket with a hefty fine or a warning? For most people, getting a ticket for violating the speed limit and having to fork over some cash to pay the fine is a powerful deterrent. In this case, enforcement has done its job. Giving you a penalty for not following the law makes you more careful in the future.

Air pollution rules are no different. Getting the rules right and then following up with strong, fair enforcement actions incentivizes industry to follow them, reduce pollution and clean up our air.

Since 2011, Wyoming environmental regulators have issued an annual study examining air emissions from numerous engines deployed in the state’s oil and gas fields. These engines power things such as compressors used to deliver natural gas to market.

It’s not surprising that the Wyoming Department of Environmental Quality (DEQ) has singled out these engines for special attention. A 2011 emission inventory for the Upper Green River Basin — a portion of the state that has struggled with ozone problems and is designated a nonattainment area by the U.S. Environmental Protection Agency for high pollution levels — found these engines to be by far the largest source of nitrogen oxide (NOx) emissions.

NOx is one of the two air pollutants that lead to harmful ozone, or smog, formation. In fact, the 2011 inventory indicates these engines emitted more than twice the NOx pollution of heaters, the next biggest source in the basin. They accounted for 1,639 of the 4,529 tons, or around 36 percent, of NOx emitted in the basin overall.

Unfortunately, the recent DEQ studies have revealed very poor performance from these engines. In 2011, more than a third of the engines tested statewide and more than half in Sublette County (the heart of the Upper Green River Basin nonattainment area) did not meet pollution standards. While the 2012 results improved somewhat, the state still found more than a quarter of the engines tested statewide to be in violation of air pollution rules. In Sublette County alone the story was even worse with 27 to 38 percent shown to exceed pollution limits. These numbers are far too high.

According to the 2011 report, “all excess emissions noted are attributed to a lack of maintenance or operational problems.” Just like your car, these engines in the oil and gas industry require routine check-ups in order to function at their best. Given the punishing conditions and long hours of operation these engines undergo in Wyoming’s oil and gas fields, this regular maintenance becomes even more important.

And as the DEQ’s 2012 report notes, “[s]imply requiring follow-up testing for failed emissions tests conducted by the Division may be inadequate to ensure that the root cause of exceedances is identified and corrected.” In other words, it may be time for stronger measures to help the oil and gas industry identify and fix these maintenance issues.

Recently the DEQ demonstrated a commitment to increased air pollution enforcement when it issued 20 notices of violation to oil and gas companies in the Niobrara shale area of east central Wyoming. This increased enforcement activity should serve as a model for what measures are needed, among others, to reduce emissions and correct violations in Wyoming’s oil and gas fields statewide — and especially in Sublette County, which recently received an “F” from the American Lung Association for its poor air quality.

The DEQ’s engine study has done its job. It has shown that there is a problem that needs attention. It is now time for the DEQ to follow up with strong enforcement actions to reduce air pollution and bring these engines back into compliance.

bookmark_borderMore Fire, Less Snow

Posted on by admin

If a tree falls in a forest and no one is around to hear it, does it make a sound?

The answer is yes, if it happened in New Mexico’s Jemez River Basin on June 26, 2011, at 1 p.m. local time.

The tipping of one tree as it creaked and fell hinted at a crackle soon to come, a fast-burning wildfire. Ultimately, the fire blazed through a large part of a 1.5 million-acre national forest.

On the day the fire started, strong, unpredictable winds blew through the trees, rustling leaves and creaking dead wood. Perhaps in a gust, a lone tree fell. On the way down, it took out a power line and sparked a fire that–by high noon the next day–had burned 43,000 acres, an acre every two seconds.

At sundown that next day, the Las Conchas Fire, as it came to be called, still ran wild. The toll had climbed to more than 61,000 acres of forest. Egged on by north winds, it jumped the trails of Pajarito Mountain Ski Area. Then it turned and raged south, threatening the town of Cochiti, N.M.

Within four days, it had singed more than 103,000 acres, making it the largest fire in New Mexico history at the time.

The forest and the watershed–the critical zone–left behind

What happened to the forests, rivers and streams the Las Conchas Fire left behind?

To find out, scientists at the National Science Foundation (NSF) Jemez River Basin and Santa Catalina Mountains Critical Zone Observatory (CZO), one of six such NSF CZOs in watersheds across the country, lit out for the hills.

The Jemez River Basin and Santa Catalina Mountains CZO is formed by twin sites: one in the Jemez River Basin in the Valles Caldera National Preserve north of Albuquerque, N.M., in the greater Rio Grande Basin; the other in the Santa Catalina Mountains northeast of Tucson, Ariz., in the Colorado River Basin.

In addition to the Jemez River Basin and Santa Catalina Mountains site in New Mexico and Arizona, NSF CZOs are located in the Southern Sierra Nevada, Christina River Basin on the border of Delaware and Pennsylvania, Susquehanna Shale Hills in Pennsylvania, Boulder Creek in the Colorado Rockies, and Luquillo National Forest in Puerto Rico.

CZO scientists provide a new understanding of the critical zone–the thin veneer of Earth that extends from the top of the forest canopy to the base of weathered bedrock.

At the Jemez River and Santa Catalina Mountains CZO, researchers are asking questions such as: How does climate variation affect arid and semi-arid ecosystems? And, how do feedbacks between critical zone structure and the cycling of water and carbon alter short-term hydrology and long-term landscape evolution?

The water cycle, the breakdown of rocks and the eventual formation of soil, the evolution of rivers and valleys, the patterns of plant growth and landforms, all result from processes that take place in the critical zone.

“The critical zone is our living environment,” says Enriqueta Barrera, program director in NSF’s Division of Earth Sciences, which funds the CZO network. “The CZOs offer us new knowledge about this important zone and its response to climate and land-use change.”

The CZOs are the first systems-based observatories dedicated to understanding how Earth’s surface processes are coupled, she says. “They will help us predict how the critical zone affects the ecosystem services on which society depends.”

Fire burns long after it’s out

Water is at the top of that list of ecosystem services.

The freshwater supplies of the American West rely, for the most part, on snow.

As snow melts into water, it begins a journey that starts in the mountains and ends in faucets. When people turn on the shower or the sprinkler, they’re watering themselves, lawns and food crops with melted snow.

The Colorado River, the Rio Grande and other rivers in the intermountain west are the main sources of water for some of the driest parts of the country, say Jemez River Basin and Santa Catalina Mountains CZO scientists Jon Chorover and Paul Brooks of the University of Arizona and Adrian Harpold of the University of Colorado.

“Their flows are predominantly fed by snowmelt from high-elevation forests and meadows,” says Brooks.

Snow-covered forests are “a critical source of water in the western U.S.,” agrees Chorover. “Forests’ ability to ‘hold snow’ can be affected by fires, tree diseases, insect-caused die-offs and other factors.”

The Las Conchas Fire provided a unique opportunity to “evaluate how forest fires interact with a changing climate,” says Harpold, first author of a recent paper on the fire’s effects on winter snow and spring snowmelt published in the journal Ecohydrology. Brooks and other scientists are co-authors.

“Forest fires have been increasing in size and severity for the last several decades,” Harpold says. “Drier and warmer than average conditions in New Mexico in 2011 contributed to fires like Las Conchas.

“When the fire removed the forest canopy, more water vapor was lost from the snow surface to the dry atmosphere, reducing the amount of water stored in the snowpack and released the following spring.”

In essence, the scientists found, areas not burned in the fire retained more snow–and snowmelt water.

Into the Valles Caldera

The Valles Caldera National Preserve, it’s called, a parkland that surrounds the Valles Caldera, a 13.7 mile wide volcanic caldera in the Jemez Mountains of northern New Mexico. The preserve overlaps the Jemez River Basin CZO.

Valles Caldera National Preserve was the site of the scientists’ study; their research was conducted on Rabbit Mountain near the park’s southern boundary.

In November 2011, the researchers placed instruments in several catchments, or river basins, on Rabbit Mountain. The resulting information is being used to better understand the effects of fire on the water, carbon and energy cycles of the entire Jemez River Basin.

“The Jemez River Basin CZO is perfectly situated to learning how fire affects water resources,” says Brooks.

In the winter and spring of 2012, Brooks and Harpold, along with other researchers and students, collected and analyzed thousands of data points on snow depth and density in burned and unburned forests on Rabbit Mountain.

“We obtained one of the most complete data sets to date on snow hydrology and fire,” says Brooks.

Spruce-fir forests dominate Rabbit Mountain’s heights; ponderosa pines and oak scrublands cover the lower mountain.

Whether in spruce-fir or pine-oak, the Las Conchas Fire left much of Rabbit Mountain with severe burns. Dead, limbless trees, ghosts of the forest, line the horizon.

In unburned forests, about one-third of the fresh snow that fell in the winter of 2012 was caught in trees before it reached the ground. There shade and wind protection allowed it to accumulate over the winter.

Where trees were lost to the fire, more fresh snowfall made it to the ground. In the end, however, that was a double-edged sword: lack of shelter from the forest canopy resulted in more of the snowpack disappearing over the winter.

“Such changes in snowpack depth have important ramifications,” says Chorover, “for ecological health and for downstream water resources.”

After the Las Conchas Fire, if a tree falls in the forest and no one is around to hear it, does it make a sound?

If you’re listening for burbling spring brooks or streaming kitchen faucets, you may hear nothing but drip, drip, drip. Or silence.
— Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov

bookmark_borderClimate Change Time Machine

Posted on by admin

NASA has developed a web application that allows you to view the sea ice declining, sea level, carbon emissions and average temperature rising over time: Climate Time Machine

 

bookmark_borderWhat Is Global Warming

Posted on by admin

by the National Oceanic And Atmospheric Administration

What is Global Warming?

sun.jpg, photo courtesy of NOAA Photo Library
The term Global Warming refers, without any implications for the cause or magnitude, to the observation that the atmosphere near the Earth’s surface is warming. This warming is one of many kinds of climate change that the Earth has gone through in the past and will continue to go through in the future.

Why is Global Warming important?

Temperature increases will have significant impacts on human activities, including: where we can live, what food we can grow, how and where we can grow food, and where organisms we consider pests can thrive. To be prepared for the effects of these potential impacts we need to know how much the Earth is warming, how long the Earth has been warming, and what has caused the warming. Answers to these questions provide us with a better basis for making decisions related to issues such as water resources and agricultural planning.

What is the Greenhouse Effect?

Greenhouse effect image Our planet absorbs radiant energy from the sun and emits some of that energy back to space. The term greenhouse effect describes how water vapor, carbon dioxide, and other “greenhouse” gases in the atmosphere alter the return of energy to space, and in turn, change the temperature at the Earth’s surface. These greenhouse gases absorb some of the energy that is emitted from the Earth’s surface, preventing this energy from being lost to space. As a result, the lower atmosphere warms and sends some of this energy back to the Earth’s surface. When the energy is “recycled” in this way, the Earth’s surface warms.

Life on Earth would be very different without the greenhouse effect. The greenhouse effect keeps the long term annual average temperature of the Earth’s surface approximately 32°C (or about 58°F) higher than it would be otherwise.

How is the Greenhouse Effect related to Global Warming?

Greenhouse gases occur naturally in the Earth’s atmosphere, but are also being added by human activities. This happens primarily through the burning of fossil fuels, such as coal, oil and natural gas, which releases carbon dioxide to the atmosphere. Over the past century, atmospheric carbon dioxide (as measured from ice cores) has increased due to human activities from 300 to 380 parts per million (ppm), and the average Earth temperature has increased approximately 0.7°C (or about 1.3°F).
Co2 image
Given what we know about the ability of greenhouse gases to warm the Earth’s surface, it is reasonable to expect that as concentrations of greenhouse gases in the atmosphere rise above natural levels, the Earth’s surface will become increasingly warm. Many scientists have now concluded that global warming can be explained by a human-caused enhancement of the greenhouse effect.

It is important to remember both that the greenhouse effect occurs naturally, and that it has been intensified by humankind’s input of greenhouse gases into the atmosphere.

Are Ozone Holes related to Global Warming or the Greenhouse Effect?

ozone.gif, photo courtesy of NASA The formation of ozone holes is related to these scientific issues, yet is still distinct.
Ozone plays a very important, natural role in the upper atmosphere (called the stratosphere), where 90% of it exists. Stratospheric ozone acts as a shield against harmful ultraviolet (UV) radiation from the sun. This ozone can be destroyed by human-produced chemical compounds called chlorofluorocarbons, or CFCs. When these CFCs are combined with extremely cold stratospheric temperatures over the poles, solar radiation, and particular patterns of atmospheric circulation, chemical reactions occur that cause “Ozone Holes” over Antarctica (pictured above) and the Arctic.

The formation of ozone holes is related to global warming and the greenhouse effect in two ways. First, CFCs are greenhouse gases. Thus, the release of these compounds into the atmosphere will have two separate effects: to destroy ozone and to add to the greenhouse effect. Second, if stratospheric temperatures or patterns of atmospheric circulation change as part of global warming, this will affect the chemical reactions that destroy ozone and cause the ozone holes to either grow or shrink.
daily ozone image
For daily updated images of the ozone, please visit NOAA’s Stratosphere: SBUV-2 Total Ozone Page with images of the ozone from the NOAA-14 Satellite by clicking here or on image at left.

bookmark_borderSevere Weather The New Normal

Posted on by admin

Human Induced Climate Change Experiment

A study mandated by congress highlights the cost of global warming to United States citizens. One of the most significant costs is the impact of more severe weather events.

A LETTER TO THE AMERICAN PEOPLE

Climate change, once considered an issue for a distant future, has moved firmly into the present.  This report of the National Climate Assessment and Development Advisory Committee  concludes that the evidence for a changing climate has strengthened considerably since the last  National Climate Assessment report, written in 2009. Many more impacts of human-caused  climate change have now been observed. Corn producers in Iowa, oyster growers in Washington  State, and maple syrup producers in Vermont have observed changes in their local climate that  are outside of their experience. So, too, have coastal planners from Florida to Maine, water  managers in the arid Southwest and parts of the Southeast, and Native Americans on tribal lands  across the nation.

Americans are noticing changes all around them. Summers are longer and hotter, and periods of  extreme heat last longer than any living American has ever experienced. Winters are generally  shorter and warmer. Rain comes in heavier downpours, though in many regions there are longer dry spells in between.

Other changes are even more dramatic. Residents of some coastal cities see their streets flood  more regularly during storms and high tides. Inland cities near large rivers also experience more  flooding, especially in the Midwest and Northeast. Hotter and drier weather and earlier snow melt mean that wildfires in the West start earlier in the year, last later into the fall, threaten more homes, cause more evacuations, and burn more acreage. In Alaska, the summer sea ice that once protected the coasts has receded, and fall storms now cause more erosion and damage that is severe enough that some communities are already facing relocation.

Scientists studying climate change confirm that these observations are consistent with Earth’s  climatic trends. Long-term, independent records from weather stations, satellites, ocean buoys, tide gauges, and many other data sources all confirm the fact that our nation, like the rest of the world, is warming, precipitation patterns are changing, sea level is rising, and some types of  extreme weather events are increasing. These and other observed climatic changes are having 26 wide-ranging impacts in every region of our country and most sectors of our economy. Some of these changes can be beneficial, such as longer growing seasons in many regions and a longer shipping season on the Great Lakes. But many more have already proven to be detrimental, largely because society and its infrastructure were designed for the climate of the past, not for the rapidly changing climate of the present or the future.

This National Climate Assessment collects, integrates, and assesses observations and research  from around the country, helping to show what is actually happening and what it means for peoples’ lives, livelihoods, and future. This report includes analyses of impacts on seven selected sectors: human health, water, energy, transportation, agriculture, forests, and ecosystems and biodiversity. This report additionally focuses on the interactions among several sectors at the  national level. It also assesses key impacts on the regions of the U.S.: Northeast, Southeast and Caribbean, Midwest, Great Plains, Southwest, Northwest, Alaska and the Arctic, Hawaii and the Pacific Islands; as well as coastal areas, oceans, and marine resources. Finally, this report is the  first to explicitly assess the current state of adaptation, mitigation, and decision support activities.

STUDY

1. Executive Summary

2. Our Changing Climate

Introduction to Sectors

3. Water Resources

4. Energy Supply and Use

5. Transportation

6. Agriculture

7. Forestry

8. Ecosystems, Biodiversity, and Ecosystem Services

9. Human Health

10. Water, Energy, and Land Use

11. Urban Systems, Infrastructure, and Vulnerability

12. Impacts of Climate Change on Tribal, Indigenous, and Native Lands and Resources

13. Land Use and Land Cover Change

14. Rural Communities

15. Interactions of Climate Change and Biogeochemical Cycles

Introduction to Regions

16. Northeast

17. Southeast and Caribbean

18. Midwest

19. Great Plains

20. Southwest*

21. Northwest

22. Alaska and the Arctic

23. Hawaii and the U.S. Affiliated Pacific Islands

24. Oceans and Marine Resources

25. Coastal Zone Development and Ecosystems

Introduction to Response Strategies

26. Decision Support: Supporting Policy, Planning, and Resource Management Decisions in a Climate Change Context

27. Mitigation

28. Adaptation

29. Research Agenda for Climate Change Science

30. The NCA Long-Term Process: Vision and Future Development

Appendix I: NCA Climate Science – Addressing Commonly Asked Questions from A to Z

Appendix II: The Science of Climate Change

bookmark_borderWarmest Year on Record

Posted on by admin

The Human Induced Climate Change Experiment

According to NOAA scientists, the average temperature for the contiguous U.S. for 2012 was 55.3°F, which was 3.2°F above the 20th century average and 1.0°F above the previous record from 1998. The year consisted of the fourth warmest winter, a record warm spring, the second warmest summer, and a warmer-than-average autumn. Although the last four months of 2012 did not bring the same unusual warmth as the first 8 months of the year, the September through December temperatures were warm enough for 2012 to remain the record warmest year, by a wide margin.

The average precipitation total for the contiguous U.S. for 2012 was 26.57 inches, 2.57 inches below average, and the 15th driest year on record for the nation.

The U.S. Climate Extremes Index indicated that 2012 was the second most extreme year on record for the nation. The index, which evaluates extremes in temperature and precipitation, as well as landfalling tropical cyclones, was nearly twice the average value and second only to 1998.

Additional Resources        

bookmark_borderNational Snow And Ice For 2012

Posted on by admin

State of the Climate
National Snow & Ice
Annual 2012
National Oceanic and Atmospheric Administration
National Climatic Data Center

The 2011/12 winter season was nearly non-existent for much of the eastern half of the nation. The December 2011-February 2012 three-month period was marked by near-record warmth across the U.S.-Canadian border, the Midwest, Mid-Atlantic, and Northeast, limiting seasonal snowfall across those regions. Many locations had near-record low snowfall totals for the winter season. Early spring brought much of the same, when the contiguous U.S. had its warmest March on record, with a monthly temperature 8.6°F above average. The lack of snowfall and snowpack for the winter and spring across the Rockies, Great Plains, and Midwest was a precursor to the large drought episode that impacted two-thirds of the nation during the summer and autumn of 2012. In contrast to the rest of the nation, the Pacific Northwest was closer to average during winter in terms of temperature and precipitation, with several winter storms bringing heavy snowfall to the high elevations. The early-spring was wetter and cooler than average for the Northwest, contributing to above-average snowfall for many locations in the region.

US Winter snow extent anomalies
Contiguous U.S. Winter Snow Cover Extent Anomalies
Data Source: Rutgers Global Snow Lab

According to data from the Rutgers Global Snow Lab, both the winter and spring seasons brought below-average snow cover to the contiguous United States. The satellite-derived snow cover extent for December 2011-February 2012 was approximately 237,000 square miles below the 1981-2010 average — the third smallest winter snow cover footprint in the 46-year satellite record. This was the first winter since 2005-2006 with below-average snow cover for the country. Only the winter seasons of 1991/92 and 1980/81 had smaller snow cover extents. The March-May spring snow cover extent was 151,000 square miles below the 1981-2010 average — the third smallest spring snow cover extent on record. The springs of 1968 and 2000 had smaller seasonal snow cover footprints.

Western US Snowpack 1 May 2012
Western U.S. Snowpack
April 1, 2012
Source: USDA

Winter and spring mountain snowpack provide a crucial water source across much of the western United States. The total annual water budget for agriculture and human use in the mountainous West is highly dependant on the amount of snow melt that will occur in spring and is proportional to the amount of snow on the ground. The annual snowpack typically reaches its maximum value at the end of March. According to data from the USDA, on April 1st, 2012, above-normal snowpack was observed through the Cascades of Oregon and Washington, with near-normal snowpack stretching eastward through the northern Rockies of Idaho, Montana, and northern Wyoming. To the south, below and much-below snowpack was observed for the Sierra Nevada Mountains, the Great Basin, and the Central and Southern Rockies. Snowpack totals less than 50 percent of normal were widespread in California, Nevada, Utah, Colorado, Arizona, and New Mexico. In Alaska, snowpack totals were above normal for the Southern coasts and peninsula, and below-normal across the North Slope.

Select Significant Events

A strong and powerful winter storm moved across the Southern Rockies and High Plains of Colorado, New Mexico, Texas, Oklahoma, and Kansas on December 19th and 20th of 2011. Snowfall up to 15 inches was reported across the region, and strong winds in excess of 50 mph created blizzard conditions. Parts of Interstates 25 and 70 were closed, and the storm was blamed for six deaths. Dalhart, Texas, shattered its daily snowfall record, where 7.0 inches fell on the 19th, surpassing the 0.1 inch which fell on the date in 1983. The 8.2 inches that accumulated in Pueblo, Colorado during the two-day event contributed to the city having its snowiest December on record, with 18.6 inches falling throughout the month. This surpassed the previous December record of 18.2 inches, which fell in December 1913.

Satellite Image of December 19-20 Snow Cover
Satellite Image of Pacific Northwest Snowcover
Source: NASA

A large and powerful winter storm, accompanied by a surge of moisture from the tropics often referred to as an atmospheric river or the ‘Pineapple Express’, impacted the western U.S. January 18th–23rd. The worst impacts were felt across the Pacific Northwest, where several feet of snow accumulated and strong winds were observed, causing icy roads, downed power lines, and avalanches. A state of emergency was declared for much of Oregon and Washington, where over a quarter-million households lost electricity. Impressive wind, snow, and rain measurements were made during the event Mount Hood, Oregon received over 50 inches of snow, winds approaching 90 mph were measured at Summer Lake, Oregon, and over 15 inches of rain fell at Swiss Home, Oregon. The Mary’s River in Philomath, Oregon crested at its highest flood height on record. Seven inches of snow fell in Seattle, which averages only 8 inches of snow a year. To the south, across the high terrain of California and Nevada, the precipitation was a welcome sight, where very dry conditions had previously dominated during the 2011-2012 winter season. Nevada’s Carson River Basin had snowpack only 8 percent of normal before the storm (compared to 224 percent at the same point in January 2011, one year prior).

A record-breaking snow storm impacted eastern Colorado and parts of Nebraska February 2nd–4th. The slow moving storm dropped 15.9 inches of snow in Denver, a new February snow storm record, surpassing the previous record of 14.1 inches set in February 1912. The 22.7 inches that fell in Boulder was also a February record. Snow accumulations greater than three feet were widespread across the region’s highest terrain. Storms of this magnitude are more common in the region during the early spring months of March and April. As the storm moved off to the east it dropped upwards of a foot of snow across much of Nebraska. The 11.1 inches that accumulated in Lincoln, Nebraska was the fourth largest 24-hour snowfall on record for the city.

Snow totals Feb 29 2012
Satellite Image of CO and NE Snow Cover
Source: NWS

A potent storm system on February 28th and 29th brought heavy snowfall and blizzard conditions across the Northern Plains, Great Lakes, and into the Northeast. Snowfall totals exceeding one foot fell in a string of states from South Dakota to Maine. The heaviest snow fell across Minnesota and Wisconsin, where snow totals approached two feet, accompanied by winds gusting to 50 mph, creating blizzard conditions for several hours. The snow from this storm was one of the few snow events this season across many of the regions affected. Much of the Northern Plains, Great Lakes

Pacific NW March 22 snowfall
22 March Pacific Northwest Snowfall
Source: National Snow Analysis

During March, as much of the eastern U.S. was basking in record breaking warmth, an upper-level trough brought cooler-than-average conditions and late-season precipitation to the Pacific Northwest. On March 22nd, a large Pacific extra-tropical cyclone slammed into the West Coast, dumping upwards of three feet of snow across the high elevations of the Washington and Oregon Cascade Mountains. The 0.5 inch of snow that fell at the Portland, Oregon airport was the largest snowfall accumulation this late in the season. Salem and Eugene, Oregon both set new March snow storm records with 2.5 and 7.5 inches of snow, respectively. This storm was part of a larger and persistent weather pattern which brought much-above-average precipitation and below-average temperatures to the region during March. The 7.89 inches of precipitation that accumulated in Portland was a new monthly record.

April 24th Northeast Snow Depth
24 April Northeast Snow Depth
Source: NOAA NNVL

A late-season storm dropped over a foot of snow from West Virginia to Upstate New York, along the higher elevations of central and northern Appalachian Mountains, on April 23rd and 24th. To the east, in the lower elevations, heavy rain fell across the large cities of the Northeast. This type of coastal storm, called a Nor’easter, was only the second of the season to impact the eastern seaboard, with the other being very early in the season in October. The snow storm was also on the heels of the warmest March on record for many locations across the region, where most trees already had begun to leaf. The snow falling on trees with leaves caused additional headaches by bringing down limbs and cutting power to at least 75,000 residents. The storm also resulted in at least 48 daily snowfall records. Although the storm did have some negative impacts, it provided drought-relieving precipitation for many locations in the Northeast.

Sandy Snowfall Totals
Sandy remnant-low snowfall totals

The remnant low pressure system from Hurricane Sandy dropped copious amounts of snow across the Southern and Central Appalachians as it moved westward after making landfall near Atlantic City, New Jersey on October 29th. Over a foot of snow was reported in six states from North Carolina to Pennsylvania, shattering October monthly snowfall records. Widespread, heavy snow of this magnitude during October has never been observed across this region. The largest snow totals occurred along the highest elevations of the Appalachians, with Mount Leconte, Tennessee receiving 33 inches of snow and Terra Alta, West Virginia measuring 36 inches. Very strong winds combined with the snow to create blizzard conditions for up to two days in some locations. The largest impacts of the storm were the massive power outages due to downed trees and power lines and building collapses because of the heavy, wet nature of the snow. Flooding was also a concern as warm temperatures returned quickly after the storm causing rapid melt and runoff.

Citing This Report

NOAA National Climatic Data Center, State of the Climate: National Snow & Ice for Annual 2012

bookmark_borderHot. Hot. Hot.

Posted on by admin

Australia — Temperatures in Australia are reaching high heights with the current heat wave. Bush fires are burning wild. Tomorrow, the  temperature is forecast as a high of 50 degrees… 50 centigrade… that’s 122 Fahrenheit.