on record for the nation with a seasonally-averaged

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2 Summer 2012 was 4% above normal and ranked as the 19th wettest since Slightly above-normal precipitation was found in small areas in southern B.C., Saskatchewan, Yukon, Northwest Territories, and northern Quebec. Below normal precipitation was observed in northern B.C., northern Northwest Territories, Ontario, southern Quebec, Newfoundland and Labrador, and Nova Scotia. During fall, the national average precipitation remained near normal (2% below normal), ranking as the 30th driest since Drier-than-normal conditions were observed in central B.C., southern Alberta and Saskatchewan, most of Nunavut, and the northern Northwest Territories. Southern B.C., northeastern B.C., northern Alberta, northern Saskatchewan, most of Manitoba, northern Quebec, and part of the Maritimes all experienced wetter-thannormal conditions. (iii) Notable events Hot temperature events dominated the list of the major Canadian weather stories in The year 2012 featured a winter that went missing, a March with broken records, and a summer that was the warmest of the warm seasons. In 2012, Canadians witnessed an almost total absence of winter. In Toronto, snowfall was a record low 41.8 cm; there were no days with measurable snow after March 1 and only nine days with more than 1 cm of snow from November to April. In Montreal, overnight lows never dipped below -20 C (the mark of a cold Canadian day), which was a first for the record books. The average afternoon temperature for Saskatoon in December and January hit -3.2 C, which was the warmest in records going back to the 1880s. In March, summer-like temperatures affected numerous locations across Canada. Fort Frances reached 26 C and on 19 March the town recorded a minimum temperature of 15.1 C. Winnipeg registered a maximum temperature of 20.9 C on 19 March, its earliest recording of temperature above 20 C in a calendar year. Halifax reported a maximum temperature of 27.2 C on 22 March, shattering its previous record of 11.8 C set in On 21 March, Petawawa recorded a maximum temperature of 28.8 C the highest temperature ever recorded in Ontario in March. Flooding due to intense precipitation events were also among the major weather events in Late on 26 May, a low-pressure system that moved from North Dakota and sat on Thunder Bay brought between 35 mm and 120 mm of rain (including 71 mm in less than six hours). The ensuing flash flood caused washouts on numerous roads and trails, cut power to homes and businesses, and filled thousands of basements with up to two meters of dirty sewage water. On 29 May, a pair of rainstorms combined to deliver more than 100 mm rain to much of Montreal, producing widespread flooding and power outages in the area. The first storm brought up to 40 mm of rain and twelve hours later a brief but more powerful storm dumped an additional 50 mm to 80 mm of rain on the city. The storms also caused power failures affecting people. On 22 July, an intense downpour in Hamilton dumped 140 mm on the city in less than four hours. 2) United States J. Crouch, R. R. Heim Jr., P. Hughes, and C. Fenimore Based on preliminary data, the annual average temperature in 2012 for the contiguous United States (CONUS) was 13.0 C, which is 1.8 C above the average and the warmest year since records began in 1895 (Fig. 7.5) surpassed the previous record warm year of 2006 by 0.6 C. The nationally-averaged precipitation during 2012 was mm, 65.3 mm below average. (i) Temperature Anomalous warmth dominated much of 2012, with each state in the CONUS having above-normal temperatures and many locations having record warm annual temperatures (Fig. 7.6a). Winter (December February) 2011/12 was the third warmest on record for the nation with a seasonally-averaged Fig 7.5. Annual mean temperature for the contiguous United States for the period The filter is a weighted average used to smooth the year-to-year changes in the data values which may help identify the presence/absence of trends throughout the data record. (Source: NOAA/NCDC.) STATE OF THE CLIMATE IN 2012 August 2013 S149

3 States were warmer than normal, while the Southeast and Northeast were near-normal. The CONUS fall (September November) temperature was 0.6 C above average, with above-normal temperatures in the West and below-normal temperatures in the East. Nevada had its warmest fall on record. Fig Climate division ranks of annual 2012 (a) temperature and (b) precipitation. Record coldest/warmest or driest/wettest is defined as the smallest/largest annual value for that climate division in the period of record. Above-normal temperature/precipitation is defined as occurring in the warmest/wettest third of recorded years. Whereas, much-below-normal temperature/precipitation falls in the bottom 10% of coolest/driest years since 1895, and below normal is defined as the coolest/driest third of the distribution. (Source: NOAA/NCDC.) temperature 2.2 C above average. Warmer-thanaverage temperatures were present for most of the nation, with near-average temperatures across parts of the West. Spring (March May) was the warmest on record with an average temperature 2.9 C above average and consisted of a record warm March, third warmest April, and second warmest May. Record warmth occurred in 34 states from the Rockies to New England. Only Oregon and Washington had nearnormal spring temperatures. The nationally-averaged summer (June August) temperature was the second warmest on record, slightly cooler than the summer of 1936, at 1.4 C above average, and consisted of the 11th warmest June, record warmest July (and warmest month of any month on record), and the 13th warmest August. Much of the central and northeastern United (ii) Precipitation Precipitation for the CONUS in 2012 was below normal and ranked as the 15th driest year on record and the driest since The year was characterized by drier-than-average conditions for much of the central United States and the central East Coast. It was the driest year on record for Colorado, Montana, Nebraska, and Wyoming. The Northwest, central Gulf Coast, and parts of the Northeast were wetter than average. The year began with 32% of the CONUS in moderate to exceptional drought (based on the U.S. Drought Monitor), mainly across the Southern Rockies and Plains, Upper Midwest, and the Southeast. By the end of 2012, nearly 58% of the CONUS was experiencing drought conditions. Winter precipitation was below normal. The Southern Plains were wetter-than-average, helping to ameliorate drought conditions that impacted the region during much of Drier-than-average conditions occurred along the West Coast, Canadian border, and Eastern Seaboard. The warm and dry winter, particularly across the western and northern United States, limited winter snow cover extent to the third smallest in the 46-year satellite record. At the end of the winter season, mountain snowpack was less than 50% of normal across the Great Basin and Central and Southern Rockies. Above-normal snowpack occurred in the Cascades and Northern Rockies. Spring was slightly drier than average for the CONUS. Below-normal precipitation occurred in the central Rockies and Midwest. Six states in those two regions had seasonal precipitation totals ranking among their 10 driest. Above-normal precipitation occurred in the Pacific Northwest and Upper Midwest. Minnesota, Oregon, and Washington each had a top 10 wet spring. Summer was the 14th driest on record with precipitation 88% of normal. Above-normal precipitation occurred in New England, the Far West. and along the Gulf Coast. Florida had its wettest summer on record, with 137% of normal, partially attributable to Tropical Storm Debby and Hurricane Isaac. The central Rockies and Midwest were much drier than average. Nebraska and Wyoming each had their driest summer on record, with seasonal precipitation 40% and 44% of average, respectively. The spatial extent S150 August 2013

4 Sidebar 7.1: BILLION-DOLLAR WEATHER AND CLIMATE DISASTERS: 2012 IN CONTEXT A. Smith The United States sustained 11 weather/climate-related disasters during 2012, in which overall damages/costs reached or exceeded $1 billion (US dollars; Fig. SB7.1). The total direct losses (i.e., insured and uninsured losses) for these 11 events exceeded $110 billion. Of these events, seven resulted from severe weather or tornado events, two were related to hurricanes/post-tropical cyclones, and the final two were the yearlong drought and the associated wildfires. The number of billion-dollar disasters in 2012 (11) is less than the number that occurred in 2011 (14), which is the largest of the 1980 present record. However, despite fewer billiondollar events, the damage in 2012 surpassed 2011 [$60 billion, Consumer Price Index (CPI)-adjusted to 2012 dollars] in terms of aggregate costs for annual billion-dollar disasters. The greatest annual loss occurred in 2005 (exceeding $187 billion, CPI-adjusted to 2012 dollars). In fact, the loss from Hurricane Katrina alone that year ($146.3 billion, CPI-adjusted to 2012 dollars) was greater than the total loss estimated for Insured and uninsured direct losses include: physical damage to residential, commercial and government/ municipal buildings, material assets within a building, time element losses (i.e., time-cost for businesses and hotel costs for loss of living quarters), vehicles, public and private infrastructure, and agricultural assets (e.g., buildings, machinery, livestock). These statistics were taken from a Fig. SB7.1 This map denotes the approximate location for each of the 11 billion-dollar weather and climate disasters that impacted the United States during wide variety of datasets, public and private, which represent the estimated total costs of these events that is, the costs in terms of dollars that would not have been incurred had the event not taken place. In 2012, NOAA's National Climatic Data Center reviewed its methodology on how it develops billion-dollar disaster reports. NCDC worked with economic experts and a consulting partner to examine possible inaccuracies and biases in the data sources and methodology used in developing the loss assessments from 1980 to 2012 (Smith et al. 2013). These efforts ensure more consistency in the values NCDC provides on an annual basis and provide more confidence in year-to-year comparisons. The most up-to-date information is available at of the summer drought peaked in July, when 61.8% of the CONUS experienced moderate-to-exceptional drought (according to the Palmer Drought Severity Index), roughly equaling the drought episodes of the 1950s, but smaller than the drought episodes of the 1930s. The hot and dry weather depleted soil moisture and reduced crop yield. The corn crop was especially ravaged, with annual production 28% below earlyseason forecasts, according to the U.S. Department of Agriculture ( aspx#crop). Fall precipitation was below average for the CONUS. Below-normal precipitation occurred for most of the Great Plains, Rockies, and Southeast, with above-normal precipitation in the Northwest, Ohio Valley, and Northeast. Below-average precipitation during consecutive seasons and the expansive drought resulted in near-record low water levels along the Mississippi River and western Great Lakes slowing commercial shipping during the last months of STATE OF THE CLIMATE IN 2012 August 2013 S151

5 (iii) Notable Events Tornado activity during 2012 was much below average, with 925 tornadoes being confirmed during the year, compared to the average of approximately 1200 tornadoes annually. This is the least number of tornadoes to impact the United States since Of the 68 tornado-related fatalities during 2012, at least 62 resulted during above-average activity in February, March, and April. Following those initial large outbreaks, tornado activity was relatively quiet for the rest of Less than half of the average number of tornadoes occurred during May and June, typically the most active tornado months of the year. During 2012, approximately fires burned over 3.7 million hectares across the United States The total area burned was the third most on record, and the low total number of fires resulted in the largest average fire size in the 13-year period of record. The largest fire in New Mexico s history charred nearly hectares, while Colorado was impacted by two devastating fires. One destroyed approximately 350 homes making it the most destructive fire in Colorado s history and the other was the second largest, in terms of acreage burned, on record for the state. Post-tropical cyclone Sandy made landfall along the New Jersey coast in late October with sustained winds of 67 kts (34.7 m s -1 ). The storm s large size contributed to a significant storm surge along the Northeast coast, where several locations experienced record high water levels, including the Battery in New York City. Sandy also brought record early-season snowfall to the central Appalachians. The storm resulted in 159 direct and indirect fatalities and at least $70 billion (US dollars) in damages (see Sidebar 4.1 for further details on this storm). 3) Mexico R. Pascual, A. Albanil, J. L. Vazquez, and R. Lobato After exceptional drought conditions in 2011, near-normal precipitation was observed in Mexico during 2012; nonetheless, the moisture deficit that persisted during the previous 24 months did not vanish completely. An initial estimate of total precipitation for 2012 in Mexico was about 742 mm, below the long-term mean since 1941, whereas the mean annual temperature was 22.0 C, +1.2 C above normal ( base period). (i) Temperature Mean temperature in Mexico observed in 2012 (22.0 C) was above normal (+1.2 C), ranking as the second warmest year on record since 1971 (Fig. 7.7), exceeded only by All months except February Fig 7.7. Annual mean temperature anomaly ( C) in Mexico (bars) and linear trend. Departures are depicted as deviations from the mean. (Source: National Meteorological Service of Mexico, SMN.) (-0.3 C) recorded a mean temperature above normal. The highest positive anomaly occurred in August (+2.7 C). The above-normal pattern was also observed in quarterly analyses. April June (+1.5 C) and July September (+1.9 C) ranked as third warmest for their respective periods whereas October December (+2 C) ranked as warmest in record for that period since 1971 (Fig. 7.8). Northeastern states such as Coahuila, Nuevo León, and Tamaulipas reported the highest anomalies in mean temperature (+2.7 C, +2.6 C, +2.9 C, respectively), as did Chihuahua (+2.6 C) in northern Mexico. A similar pattern was observed in southeastern states such as Quintana Roo (+1.7 C), Campeche (+1.4 C), Chiapas (+1.2 C), Tabasco (+1.0 C), and Yucatan (+0.8 C). However, near-normal mean temperatures were observed in northwestern and central states, where positive temperature anomalies were relatively small (Sonora and Sinaloa, +0.5 C; Puebla, +0.3 C). Temperatures in central and eastern Mexico remained within the normal range (Fig. 7.9a). (ii) Precipitation Average annual precipitation in 2012 was approximately mm, 4.4% below the long-term mean (25th driest since 1941). About 49% of the country, mostly in the north, observed below-normal precipitation (less than 85%); 35% of the country received near-normal precipitation (between 85% and 115% of the long-term mean) and 15% observed above-normal precipitation (Fig. 7.9b). Fig 7.8. Daily mean temperature ( C) in Mexico observed along 2012 (solid line) compared to the mean (dotted line) and a range of ±2 std dev (shaded area). Anomalies are derived from base period. (Source: SMN.) S152 August 2013