Google Search

For weather information from across the nation, please check out our home site National Weather Outlook. Thanks!

Chicago Current Weather Conditions

Chicago Weather Forecast

Chicago 7 Day Weather Forecast

Chicago Weather Radar

Showing posts with label warmest. Show all posts
Showing posts with label warmest. Show all posts

Tuesday, February 10, 2015

NASA, NOAA find 2014 warmest year in modern record

The year 2014 ranks as Earth's warmest since 1880, according to two separate analyses by NASA and National Oceanic and Atmospheric Administration (NOAA) scientists.

The 10 warmest years in the instrumental record, with the exception of 1998, have now occurred since 2000. This trend continues a long-term warming of the planet, according to an analysis of surface temperature measurements by scientists at NASA's Goddard Institute of Space Studies (GISS) in New York.

In an independent analysis of the raw data, also released Friday, NOAA scientists also found 2014 to be the warmest on record.

"NASA is at the forefront of the scientific investigation of the dynamics of the Earth's climate on a global scale," said John Grunsfeld, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. "The observed long-term warming trend and the ranking of 2014 as the warmest year on record reinforces the importance for NASA to study Earth as a complete system, and particularly to understand the role and impacts of human activity."

Since 1880, Earth's average surface temperature has warmed by about 1.4 degrees Fahrenheit (0.8 degrees Celsius), a trend that is largely driven by the increase in carbon dioxide and other human emissions into the planet's atmosphere. The majority of that warming has occurred in the past three decades.

"This is the latest in a series of warm years, in a series of warm decades. While the ranking of individual years can be affected by chaotic weather patterns, the long-term trends are attributable to drivers of climate change that right now are dominated by human emissions of greenhouse gases," said GISS Director Gavin Schmidt.

While 2014 temperatures continue the planet's long-term warming trend, scientists still expect to see year-to-year fluctuations in average global temperature caused by phenomena such as El Ni?o or La Ni?a. These phenomena warm or cool the tropical Pacific and are thought to have played a role in the flattening of the long-term warming trend over the past 15 years. However, 2014's record warmth occurred during an El Ni?o-neutral year.

"NOAA provides decision makers with timely and trusted science-based information about our changing world," said Richard Spinrad, NOAA chief scientist. "As we monitor changes in our climate, demand for the environmental intelligence NOAA provides is only growing. It's critical that we continue to work with our partners, like NASA, to observe these changes and to provide the information communities need to build resiliency."

Regional differences in temperature are more strongly affected by weather dynamics than the global mean. For example, in the U.S. in 2014, parts of the Midwest and East Coast were unusually cool, while Alaska and three western states -- California, Arizona and Nevada -- experienced their warmest year on record, according to NOAA.

The GISS analysis incorporates surface temperature measurements from 6,300 weather stations, ship- and buoy-based observations of sea surface temperatures, and temperature measurements from Antarctic research stations. This raw data is analyzed using an algorithm that takes into account the varied spacing of temperature stations around the globe and urban heating effects that could skew the calculation. The result is an estimate of the global average temperature difference from a baseline period of 1951 to 1980.

NOAA scientists used much of the same raw temperature data, but a different baseline period. They also employ their own methods to estimate global temperatures.

GISS is a NASA laboratory managed by the Earth Sciences Division of the agency's Goddard Space Flight Center, in Greenbelt, Maryland. The laboratory is affiliated with Columbia University's Earth Institute and School of Engineering and Applied Science in New York.

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites, as well as airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

The data set of 2014 surface temperature measurements is available at:

http://data.giss.nasa.gov/gistemp/

The methodology used to make the temperature calculation is available at:

http://data.giss.nasa.gov/gistemp/sources_v3/

For more information about NASA's Earth science activities, visit:

http://www.nasa.gov/earthrightnow


View the original article here

Thursday, December 5, 2013

Contiguous U.S. had eighth wettest and 15th warmest summer

August Extreme Weather/Climate Events
Climate Highlights — AugustThe average temperature for the contiguous U.S. during August was 73.1°F, 1.0°F above the 20th century average — the 28th warmest such month on record. The western U.S., particularly the Northwest, was warmer than average during August. Idaho had its second warmest August, with a monthly temperature of 69.4°F, 4.5°F above average. Wyoming tied its third warmest August, with a temperature of 67.8°F, 3.7°F above average.Below-average temperatures stretched from the Central Plains, through the Ohio Valley, and along most of the Eastern Seaboard, but no state had August temperatures ranking among the ten coolest.The nationally-averaged August precipitation total of 2.63 inches was 0.03 inch above average. Both wet and dry extremes were experienced across the contiguous U.S. during August, resulting in a near-average national precipitation total for the month. California, Georgia, and Kansas each experienced a top ten wet August, while Illinois, Indiana, Iowa, and Minnesota each had a top ten dry month.According to the September 3rd U.S. Drought Monitor report, 50.1 percent of the contiguous U.S experienced drought conditions, up 4.5 percent since the end of July. Drought conditions expanded into the Upper Midwest and Lower Mississippi River Valley, as well as Hawaii. Beneficial rainfall helped to improve, but not eliminate, drought conditions across the Central and Southern Plains.On a local basis, the number of record warm daily highs and lows (about 1800) during August was slightly greater than the number of record cool daily highs and lows (about 1450). Climate Highlights — summer (June – August)The summer contiguous U.S. temperature of 72.6°F was 1.2°F above the 20th century average and the 15th warmest summer on record for the nation. The West and parts of the Northeast were much warmer than average during summer. In the West, eight states, from New Mexico to Washington, had seasonal temperatures that ranked among the ten warmest on record. In the Northeast, four states had one of their ten warmest summers on record.Below-average summer temperatures were observed in the Southeast and parts of the Ohio Valley, but no state had summer temperatures ranking among the ten coolest. The Alaska statewide average summer temperature was 2.7°F above the 1971-2000 average and ranked as the second warmest summer in the 96-year period of record for the state. The warmest June-August occurred in 2004 when the statewide temperature was 4.1°F above average.The summer precipitation total for the contiguous U.S. was 9.53 inches, 1.28 inches above average. This marked the eighth wettest summer on record and the wettest since 2004. Wetter-than-average conditions were observed across much of the East, where 19 states had one of the ten wettest summer periods on record. Florida, Georgia, South Carolina, and New York each experienced record breaking statewide precipitation totals during the season. In fact, this marked the second consecutive summer of record high precipitation in Florida. Above-average precipitation was also observed in parts of the Southwest, were Arizona had its ninth wettest summer on record.The components of the U.S. Climate Extremes Index (USCEI) that examine extremes in 1-day precipitation totals and warm night time temperatures ranked as the third and fourth highest on record for the summer season, respectively. When combining all components of the USCEI, the index was above average for June-August. The USCEI is an index that tracks the highest and lowest 10 percent of extremes in temperature, precipitation, tropical cyclones, and drought across the contiguous United States.Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand during June–August was near average and ranked as 53rd highest summer value in the 119-year period of record. Climate Highlights — year-to-date (January – August)The year-to-date contiguous U.S. temperature was 54.5°F, 0.6°F above the 20th century average and was the 34th warmest January-August on record. Warmer-than-average temperatures were observed in the West and Northeast. California had its eighth warmest January-August with a temperature of 62.0°F, 2.0°F above average. Below-average temperatures stretched from the Upper Midwest, through the Mississippi River Valley, and into the Southeast. The year-to-date contiguous U.S. precipitation total of 21.77 inches was 1.57 inches above average and was the 18th wettest January-August on record. However, rainfall was not evenly distributed across the country.Dry precipitation extremes were observed in the West and wet precipitation extremes were observed in the East. California, Idaho, Nevada, and Oregon each had a top ten dry year-to-date period. California's precipitation total of 5.08 inches was record low for the eight-month period at 9.54 inches below average, and 1.27 inches less than the previous record dry January-August of 1898. Above-average precipitation was observed for most locations east of the Rockies. Eleven states across the Midwest and Southeast had year-to-date precipitation totals that ranked among the ten wettest. For the eight-month period, Georgia had 51.85 inches of precipitation, 15.46 inches above average and Michigan had 27.62 inches of precipitation, 7.07 inches above average — both states experienced a record wet January-August.For the year-to-date period, the components of the USCEI that examine extremes in 1-day precipitation totals and the spatial extent of drought ranked as seventh and ninth highest on record, respectively. When combining all components of the USCEI, the index was near average for January-August. Based on the REDTI, the contiguous U.S. temperature-related energy demand during January-August was slightly below average. Alaska had its 11th warmest August since records began in 1918, with a temperature 2.0°F (1.1°C) above the 1971–2000 average.Alaska had its 2nd warmest June-August since records began in 1918, with a temperature 2.7°F (1.5°C) above the 1971–2000 average.Alaska had its 22nd warmest January-August since records began in 1918, with a temperature 1.1°F (0.6°C) above the 1971–2000 average.Alaska had its 33rd wettest August since records began in 1918, with an anomaly that was 16.9 percent above the 1971–2000 average.Alaska had its 48th wettest June-August since records began in 1918, with an anomaly that was 2.7 percent above the 1971–2000 average.Alaska had its 24th wettest January-August since records began in 1918, with an anomaly that was 15.0 percent above the 1971–2000 average.

For additional details about recent temperatures and precipitation across the U.S., see the Regional Highlights section below and visit the Climate Summary page". For information on local temperature and precipitation records during the month, please visit NCDC's Records page.

Regional Highlights:These regional summaries were provided by the six Regional Climate Centers and reflect conditions in their respective regions. These six regions differ spatially from the nine climatic regions of the National Climatic Data Center.

Northeast Region: (Information provided by the Northeast Regional Climate Center)Following three months of above-normal temperatures, the Northeast was cooler than normal in August. With an average temperature of 67.2 degrees F (19.6 degrees C), it was 1.2 degrees F (0.7 degrees C) below normal. The lone warm state was Vermont with a departure of +0.1 degrees F (+0.1 degrees C). Departures for the rest of the states ranged from -0.3 degrees F (-0.2 degrees C) in Maine to -1.9 degrees F (-1.1 degrees C) in Maryland. As for summer, the Northeast's average temperature of 68.6 degrees F (20.3 degrees C) was 0.7 degrees F (0.4 degrees C) above normal. West Virginia ended summer at normal, while all other states were warmer than normal. In fact, seven of the region's twelve states ranked this summer among their top 20 warmest. Departures ranged from +0.2 degrees F (+0.1 degrees C) in Maryland to +1.8 degrees F (+1.00 degree C) in Massachusetts.For the fourth month in a row, the Northeast was wetter than normal. During August the region received 4.23 inches (107.44 mm) of precipitation, 108 percent of normal. While overall the region was wetter than normal, the individual states were split. West Virginia led the six wet states with 146 percent of normal, making it the state's 12th wettest August. Departures for the other wet states ranged from 129 percent of normal in Maine to 103 percent of normal in Pennsylvania. As for the six dry states, departures ranged from 97 percent of normal in New York to 71 percent of normal in Vermont. Looking at summer, the Northeast received 16.56 inches (420.62 mm) of rain, 134 percent of normal, making it the wettest summer since recordkeeping began. All states ranked this summer among their top 11 wettest, with New York seeing its wettest summer on record at 137 percent of normal precipitation. Departures for the rest of the states ranged from 119 percent of normal in Pennsylvania to 171 percent of normal in Delaware. In addition, Philadelphia, Pennsylvania, had its wettest summer on record with 29.71 inches (754.63 mm) of precipitation, beating the old record of 24.58 inches (624.33 mm) set in 2011.While August started with no areas of dryness in the Northeast, an area of abnormal dryness was introduced in north central Pennsylvania in the U.S. Drought Monitor released on August 29 due to precipitation deficits over the past 90 days.Thunderstorms in western and central Pennsylvania on the 7th produced multiple funnel clouds and wind gusts up to 90 mph (40 m/s). The storms downed trees and power lines, blew roofs off barns, and dropped hail up to 1.00 inch (2.54 cm) in diameter. Repeated thunderstorms over the same areas in central New York caused significant flash flooding on the 8th. In Tompkins County, 1.25 inches (31.75 mm) of rain fell in a 20-minute period with 24-hour rain totals of around 5.00 inches (127.00 mm) in that county and surrounding counties. In Cortland County, over a hundred people were evacuated. The heavy rains washed out roads and flooded homes and businesses. According to Press and Sun Bulletin, preliminary estimates place damage in parts of Tompkins County at around $1 million. Storms also caused flooding in parts of Pennsylvania, Connecticut, and Massachusetts on the 8th and 9th. On the 11th, three waterspouts were spotted on Lake Erie southwest of Erie, Pennsylvania. An EF-0 tornado and straight-line winds damaged trees in Harford County, Maryland, on the 13th. On the same day, an EF-0 tornado touched down in Ocean County, New Jersey. The tornado downed trees and power lines and damaged several churches. The storms that produced the tornadoes also caused flash flooding in southeastern Pennsylvania, northern Delaware, and southern New Jersey. More flash flooding occurred in New Jersey on the 22nd. Several lanes of Interstate 295 were blocked by water causing a 10-mile backup in Burlington County. On the 24th three waterspouts were spotted on the Chesapeake Bay in Maryland.For more information, please go to the Northeast Regional Climate Center Home Page.Midwest Region: (Information provided by the Midwest Regional Climate Center)August temperatures were within a couple degrees F (1 C) of normal across the Midwest. Above normal temperatures were located in the northwest parts of the region in Minnesota and a few parts of Iowa and Wisconsin. Cooler than normal temperatures stretched across the southern half of the region from Missouri to Ohio and southern Michigan. Temperatures were below average through the middle of the month followed by much warmer than normal temperatures in the last ten days of August. Freezing temperatures were recorded at a handful of Minnesota, Wisconsin, and Upper Michigan stations on August 10th and 14th. Temperatures hit 100 degrees F (37.8 C) on the 30th and 31st at multiple stations in Missouri, Iowa, and Illinois. Summer (June, July, August) temperatures were very close to normal in the Midwest.August precipitation in the Midwest varied from no precipitation to more than 20.00 inches (508 mm). The highest and lowest values were both recorded in Missouri. Stations with no precipitation for the month occurred in Iowa, Illinois, and Missouri and dozens of other stations also set new records for lowest August precipitation. Four Midwest states ranked among the driest on record (since 1895) with Illinois the 3rd driest, Indiana 4th, and Iowa and Minnesota ranked 7th driest in the history of each state. In contrast, southern parts of the Midwest were much wetter than normal with heavy rains training along a stationary front. Despite the dry condition in northern Missouri, the heavy rains in the south brought the statewide total above normal for the month. In southern Missouri, three people died in two flash flooding incidents when their cars were washed away swept away by raging water. The rains in the south had summer totals in Kentucky (3rd) and Ohio (5th) ranked among the wettest summers in history while much of the Midwest was below normal, and much below normal in Iowa and northern Missouri. In Iowa, Illinois, and Wisconsin, record wet 2013 January to June precipitation switched to very dry conditions in July and August with the recent 2-month period ranked among the driest 10% on record in each state.Dry conditions in July and early August across much of the Midwest were mitigated by cooler than normal temperatures keeping drought impacts minimal. The latter part of August however saw a continuation of the dry conditions along with much above normal temperatures and conditions quickly deteriorated over large areas. The heat was needed to help mature the crops however, crop conditions worsened sharply due to the dryness. Drought expanded from just 2 percent of the region on July 30th to more than 28 percent on September 3rd. Severe drought expanded from 0 percent to almost 7 percent of the Midwest in the same time period.For details on the weather and climate events of the Midwest, see the weekly summaries in the Midwest Climate Watch page.Southeast Region: (Information provided by the Southeast Regional Climate Center)Mean temperatures were below average across much of the Southeast region in August, except across northern Florida, Puerto Rico, and coastal sections of the Carolinas. Bartow, FL, located between Tampa and Orlando, recorded its warmest August in a record extending back to 1892, while nearby St. Petersburg tied its warmest August in a record also extending back to 1892. The greatest departures for the month were found across interior portions of Alabama, Georgia, and the Carolinas, where monthly temperatures were between 2 and 3 degrees F (1.1 and 1.6 degrees C) below average. Concord, NC, located near Charlotte, recorded its coldest August on record (1933-2013), while nearby Salisbury, NC (1893-2013) and Statesville, NC (1901-2013), recorded their second coldest August on record. The warmest weather of the month occurred between the 9th and 12th, as temperatures reached the mid and upper 90s F (35-37 degrees C) across a large part of the region. A few days later, much cooler air overspread the northern half of the region, with daily maximum temperature departures of 10 to 20 degrees F (6 to 11 degrees C) below average between the 14th and 19th of the month. Overnight temperatures were also unseasonably cool from the 24th to the 26th of the month, as minimum temperatures fell into the 50s F (10-15 degrees C) as far south as central Georgia and into the 40s F (4.4-9.4 degrees C) across the higher elevations of the Southern Appalachians.While the end of August marked the second warmest meteorological summer on record at Cape Hatteras, NC (1874-2013), mean summer temperatures across most of the region were near average for the second consecutive year. Columbus, GA (1948-2013) and Birmingham, AL (1895-2013) recorded their 4th and 5th coldest maximum summer temperature, respectively, while Daytona Beach, FL (1923-2013), Tallahassee, FL (1896-2013), and Washington D.C. (1871-2013) recorded their 4th warmest minimum summer temperature. Through the end of August, the temperature has failed to reach 100 degrees F (38 degrees C) across South Carolina and Alabama, marking the first such occurrence since 1973 and 2001, respectively.Precipitation in August was generally above normal across the Southeast, particularly across the western Panhandle of Florida, southern Alabama and Georgia, and northern South Carolina, where monthly totals exceeded 200 percent of normal. Macon, GA recorded its second wettest August on record (1892-2013) with 10.20 inches (259 mm). Much of the rainfall in the region occurred from the 14th to the 18th of the month as a frontal boundary stalled across the southern half of the region. Columbus, GA recorded 5.73 inches (145 mm) on the 14th, which ranked as the highest daily rainfall total for August and second highest total for any calendar day, falling just short of the record of 5.74 inches (146 mm) set on April 1, 1984. Columbia, SC recorded 4.38 inches (112 mm) on the 16th, which ranked as the third highest daily rainfall total for August in a record extending back to 1887. On the 6th of the month, over 5 inches (127 mm) of rain fell across the Upstate of South Carolina, resulting in one drowning death in Pickens County. Four other individuals had to be rescued along the same stretch of road after flood waters engulfed their cars. The driest locations in August were found across central and eastern portions of North Carolina, the southern shores of Puerto Rico, and much of South Florida, where monthly totals were less than 50 percent of normal. Vero Beach, FL recorded its second driest August on record (1942-2013) with only 1.47 inches (37 mm), which was more than 5 inches below normal.August marked the end of an exceptionally wet summer across many locations in the Southeast. Asheville, NC (1902-2013) recorded its wettest summer on record with 29.64 inches (753 mm), breaking the previous record of 26.06 inches (662 mm) set back in 2005. Columbus, GA also recorded its wettest summer with 24.76 inches (629 mm), breaking the previous record of 24.06 inches (611 mm) also set back in 2005. Several other locations recorded one of their wettest summers on record, including Greenville-Spartanburg, SC, Macon, GA, and San Juan, PR (second wettest); Augusta, GA and Roanoke, VA (third wettest); and Atlanta, GA (fourth wettest).There were 228 preliminary reports of severe weather across the Southeast in August, with at least one report on 23 of 31 days. Only two tornadoes were confirmed across the region. On the 2nd of the month, an EF-2 tornado caused damage to over 30 structures in the Jacksonville, FL area. One person was treated for minor injuries. On the 18th of the month, an EF-1 tornado touched down in Heard County, GA (southwest of Atlanta near the Georgia-Alabama border). At least one mobile home sustained roof damage and numerous trees were snapped.The Southeast remained free of drought in August, marking the first calendar month without any drought designation since February 2010. The wet weather over the past several months continued to affect agricultural production across the region. Saturated fields delayed the harvest of many row crops, while those that were harvested returned generally low yields compared to their five year averages. Some crops also showed signs of disease, including yellowing of pastures and peanuts and fungus on pecans. Crop dusters saw a boom in business this summer since most fields have been too wet for heavy equipment. The extent of crop damage in South Carolina forced Governor Nikki Haley to request that the state be declared an agricultural disaster area. Heavy rains and saturated soils across southern parts of Alabama, Georgia, and northern Florida delayed the planting of fall crops, while periods of drier weather aided in the preparation of fall vegetables and fruits across parts of the Florida Peninsula. In addition, the excess rain this summer contributed to a 34 percent reduction in water bills in the Atlanta area.For more information, please go to the Southeast Regional Climate Center Home Page.High Plains Region: (Information provided by the High Plains Regional Climate Center)The first half of August was quite cool across the High Plains Region with temperature departures of 4.0-10.0 degrees F (2.2-5.6 degrees C) below normal in the Dakotas and 2.0-6.0 degrees F (1.1-3.3 degrees C) below normal in Nebraska and Kansas. During this time, a ridge of high pressure was off to the west, allowing cool, dry air to flow south from Canada. However, toward the end of the month, the ridge shifted to the east and southerly flow dominated bringing some of the hottest temperatures of the summer. For instance, Bismarck, North Dakota set a record high on the 20th with a temperature of 102 degrees F (38.9 degrees C). The old record of 100 degrees F (37.8 degrees C) was set in 1976 (period of record 1874-2013). With lower than normal temperatures the first half of the month and higher than normal temperatures the last half, much of the Region ended the month near normal. The exceptions included central and southeastern Kansas with monthly temperature departures of 2.0-4.0 degrees F (1.1-2.2 degrees C) below normal and most of Wyoming which had temperature departures of 2.0-4.0 degrees F (1.1-2.2 degrees C) above normal. Temperatures have played an important role this summer as many of the impacts of dryness were staved off by cooler conditions. Unlike last year, a ridge of high pressure was just to the west of most of the Plains states which resulted in cooler, drier northerly flow for the Dakotas, Nebraska, and Kansas for much of the summer. These cooler temperatures slowed crop development - development which was already behind in many places due to either a late snowpack or wet field conditions. While crop progress was lagging, however, the cooler conditions helped with crop stress in the drier areas. By the middle of the month, there was even concern about whether or not crops would reach maturity before the first freeze of the season. But, the heat settled in for the latter half of the month and this had mixed impacts on crops. In the areas that had adequate moisture, the heat was helpful in crop development, however in the dry areas, the heat caused stress.Precipitation this month was hit or miss across the High Plains Region. The spotty precipitation led to both improvements and degradations in drought conditions. Areas such as southern Kansas, western portions of the Dakotas, and northern Nebraska received up to 300 percent of normal precipitation. Meanwhile, large areas of central Wyoming, eastern and central North Dakota, and northeastern South Dakota missed out and received less than 50 percent of normal precipitation. Embedded areas received little to no precipitation and ended the month with less than 5 percent of normal precipitation. With the wide range in precipitation, there were stations which ranked in the top 10 driest or wettest Augusts on record. For instance, Aberdeen, South Dakota received only 0.34 inches (9 mm) of precipitation this month and ranked as the 4th driest on record (period of record 1893-2013). The driest August in Aberdeen occurred in 1947 when only 0.06 inches (2 mm) of precipitation fell. On the other end of the spectrum, Wichita, Kansas had its 2nd wettest August on record with 10.98 inches (279 mm) of precipitation, most of which occurred during the first half of the month. The record 11.96 inches (304 mm) in 2005 was able to hold on (period of record 1888-2013).The heavy precipitation in southern Kansas caused flooding in several communities including Wichita and Hutchinson. Hit or miss precipitation was the theme this summer as precipitation was quite varied across the High Plains Region. Monsoonal moisture brought much needed precipitation to Colorado in July and August which helped alleviate some long and short term drought conditions while also decreasing fire danger. Unfortunately, the rain was a double edged sword as some locations dealt with destructive flash flooding in and around recent burn scars. Southern Kansas also dealt with flooding after a dry start to the summer. For instance, while Wichita started the summer off on the dry side, this summer went down as the 3rd wettest on record with a total of 20.50 inches (521 mm). June precipitation was only 35 percent of normal, while the combined July and August precipitation was 265 percent of normal. The record of 23.61 inches (600 mm) occurred in 2005. To the north, Lincoln, Nebraska had its 6th driest summer on record with only 4.60 inches (117 mm) of precipitation. This was only 0.40 inches (10 mm) off of last year - the 4th driest summer. The 1936 record of 2.84 inches (72 mm) held (period of record 1887-2013). The Dakotas were divided with eastern areas generally below normal and western areas above normal. Meanwhile, Wyoming was dry except for the northeast corner.According to the U.S. Drought Monitor, there were numerous changes in drought conditions over the past month. Significant improvements were made in Kansas and Colorado where beneficial rains fell. The exceptional drought (D4) coverage in Kansas was reduced from 25 percent to about 9 percent, while the D4 coverage in Colorado went from 15 percent to 2 percent. Unfortunately, other areas of the Region did not fare as well. Cool conditions for the first half of the month gave way to hot and dry weather which caused drought conditions to emerge and/or deteriorate rapidly in parts of eastern North Dakota, South Dakota, and Nebraska. For instance, North Dakota started the month free of drought, but ended the month with over 30 percent of the state in at least moderate drought (D1). According to the U.S. Seasonal Drought Outlook released August 15th, drought conditions should improve in portions of eastern Nebraska, central Colorado, central Kansas, and eastern North Dakota. Drought conditions were expected to persist elsewhere through November 2013.For more information, please go to the High Plains Regional Climate Center Home Page.Southern Region: (Information provided by the Southern Regional Climate Center)With the exception of Texas, August was slightly cooler than normal month across the Southern Region. In Texas, temperatures averaged between 1-4 degrees F (0.55-2.22 degrees C) above normal for the month. Texas reported a state-wide average temperature of 83.30 degrees F (28.50 degrees C), which was their twenty-fifth warmest August on record (1895-2013). Elsewhere in the region, temperatures generally averaged between 1-2 degrees F (0.56-1.11 degrees C) below normal, and in the case of northern Arkansas and central Tennessee, between 2-4 degrees F (1.11-2.22 degrees C) below normal. The other state-wide average temperatures for the month are as follows: Arkansas averaged 78.40 degrees F (25.78 degrees C), Louisiana averaged 81.60 degrees F (27.56 degrees C), Mississippi averaged 79.50 degrees F (26.39 degrees C), Oklahoma averaged 80.30 degrees F (26.83 degrees C), and Tennessee averaged 74.80 degrees F (23.78 degrees C). Tennessee experienced its twenty-second coldest August on record (1895-2013), while Mississippi experienced its twenty-eighth coldest August on record (1895-2013). All other state temperature rankings fell within the middle two quartiles.Precipitation totals in the month of August varied significantly over the Southern Region. Central portions of the region received, on average, less than half the expected precipitation. This was also the case for the western and west central counties of Texas. In Arkansas, southern counties experienced an extremely dry month, with many stations reporting less than twenty-five percent of normal rainfall. In contrast, the northern counties in Arkansas experienced a much wetter than normal month, with many stations reporting between one and a half to two times of normal. The state-wide average precipitation totals for the month are as follows: Arkansas recorded 3.95 inches (100.33 mm), Louisiana recorded 3.05 inches (77.47 mm), Mississippi recorded 3.28 inches (83.31 mm), Oklahoma recorded 2.95 inches (74.93 mm), Tennessee recorded 4.01 inches (101.85 mm), and Texas recorded 1.42 inches (36.07 mm). For Louisiana, it was their seventeenth driest August on record (1895-2013), while for Texas, it was their twenty-eighth driest August on record (1895-2013). All other state rankings for the month fell within the two middle quartiles.Drought conditions changed significantly over the month of August. Much of western and northern Louisiana is now experiencing severe drought. This is also the case for southern Arkansas, and west central Mississippi, which also saw little in the way of precipitation. In Texas, the central counties of the state saw a one category deterioration, while the north western corner of the state experienced some improvements. Despite this, much of that portion of Texas is still under the severe grip of drought.There was little in the way of severe weather across the region in August. On August 7, 2013, three tornadoes were reported in the north western corner of the region, however; no injuries were documented.In Texas, August started and ended with high temperatures pushing triple digits; warranting several days of high heat warnings across the state. Many outdoor activities were interrupted over the course of the month, with additional stresses to the state's power supply. The heat affected different businesses in different ways, with water parks seeing boosts in numbers, while tourist traps like the River Walk in San Antonio lost revenue (Information provided by the Texas Office of State Climatology).Drought conditions throughout the month have been particularly taxing to Texas farmers. Cotton yields are expected to be only half of that planted due to dry conditions, while rice farmers along the coast will not see a second crop at all because of low water on the Brazos River. The middle of the month, however, did see some rainfall and cooler temperatures, but not without problems of their own. Storms dropped several inches of rain and hail in the Panhandle, ruining late season crops and possibly prompting disaster declaration, and caused over 100,000 customers in Houston to go without power on August 16, 2013. The high heat has compounded the already problematic hydrological drought with new short-term deficits, leading to high fire risks and poor crop moisture profiles, particularly in the eastern and southern parts of Texas. Burn bans are present in 190 counties and most cities seeing some sort of water restriction in place, including Pflugerville implementing new Stage 3 restrictions for the first time ever. Lake Travis has dropped low enough to prompt the shutdown of a new $140 million water treatment facility in Cedar Park. A recent $2 billion funding bill for water resources is even seeing controversy with rural residents concerned that their water supplies will be used for city-use only (Information provided by the Texas Office of State Climatology).For more information, please go to the Southern Regional Climate Center Home Page.Western Region: (Information provided by the Western Regional Climate Center)Many locations in the West experienced wetter than normal conditions this month as an active monsoon pattern and slow-moving low-pressure systems enhanced thunderstorm activity. Persistent low pressure over the coast and frequent thunderstorms in the Southwest acted to moderate temperatures in these areas. Strong high pressure over the central and southern Rockies brought record high temperatures to the inland Northwest. Several large fires burned throughout the West, impacting air quality and visibility.On the heels of one of the driest Julys on record, August brought scattered heavy precipitation to the Northwest. Wenatchee, in central Washington, received 1.91 in (48 mm) of rain and logged its second wettest August since records began in 1959. Of this total, 1.09 in (28 mm) fell in one hour on August 1st. Redmond, Oregon saw 1.16 in (29 mm) precipitation, 232% of normal and the 8th wettest August in a 67-year record. Areas of Nevada also experienced heavy monsoonal precipitation. Rainfall in Reno totaled 1.08 in (27 mm), the 4th wettest August in the past 77 years. Needles, in California's Mojave Desert, recorded 2.84 in (72 mm), nearly 600% of normal and the 4th wettest in a 66-year record. Significant monsoon moisture also reached northern Arizona, southern Utah, and parts of Colorado. Flagstaff, Arizona had its 11th wettest August on record at 4.85 in (123 mm), 156% of normal. During July and August, Colorado Springs logged 10.33 in (262 mm) rainfall, the second wettest such period in 66 years. Areas of near-normal summer rainfall helped to alleviate some of the exceptional drought in southeastern Colorado.Following a wet July, August precipitation totals were lackluster in southern Arizona and New Mexico. Tucson, Phoenix, and Yuma, Arizona all reported below normal precipitation for the month. After receiving nearly 200% of normal precipitation in July, Albuquerque, New Mexico, received 0.42 in (11 mm), a scant 30% of its normal August precipitation. This summer's precipitation did help to improve drought conditions throughout the state. After a drier than normal summer, severe drought continued for much of western Wyoming. Riverton reported only 0.05 in (1 mm) for the month, 10% of normal. Some improvements in drought conditions were seen in the northeastern portion of the state where normal rainfall totals were received this summer.Many coastal areas saw persistent fog and slightly cooler than normal temperatures. Los Angeles, California reported 22 days with fog this month, 5 days above the average 17 and was 1.0 F (0.5 C) cooler than the August average. Meanwhile, temperatures soared throughout the inland Northwest. Daily temperatures in Salt Lake City, Utah averaged 82.7 F (28.2 C) for the month, the hottest August in a 140-year record. This was also Salt Lake's warmest summer at an average 80.7 F (27.1 C). Boise, Idaho also saw its warmest summer on a 74-year record at an average 76.5 F (24.7 C). Following its all-time hottest month in July, Yakima, Washington averaged 73.2 F (22.9 C) this month, a tie with 1961 for second warmest August since records began in 1947. Temperatures were also warmer than normal throughout Montana; Billings averaged 75.0 F (23.9 C), the 8th warmest in an 80-year record. Elsewhere in the region, Laramie, Wyoming recorded its 2nd warmest summer since records began in 1948 at an average 64.3 F (17.9 C).August wrapped up a warmer than normal summer for much of Alaska. On August 8th, Fairbanks hit its 36th day in a calendar year with a high over 80 F (26.7 C). This breaks the record of 30 days set in 2004. However, on the last day Bettles fell to a frosty record 15 F / -9.4 C. Southern Alaska was wetter than normal with Kodiak and Cold Bay both logging their second wettest August on record at 9.3 in (236 mm) and 6.49 in (165 mm), respectively. Further south, dry conditions continued to dominate throughout Hawaii with most stations across the state reporting less than 50% of normal rainfall. A few locations, such as Molokai and Kaneohe, Oahu logged above normal precipitation.August (all month): Wildfires in the West: Though many large fires burned throughout the West this month, year-to-date the nationwide number of fires is 64% of the 10-year average and acres burned stands at 63% of the 10-year normal. The largest fires include:Rim Fire, California: This fire began August 17, cause unknown. It has since charred over 230,000 acres (93,077 hectares) and become the 4th largest fire in California history. Smoke transported by southwesterly flow brought hazardous air quality to downwind locations such as the Lake Tahoe Basin and west-central Nevada including Reno and Carson City.Beaver Creek and Elk Complex Fires, Central Idaho: These lightning-caused fires began August 7th and 8th and grew to over 110,000 acres (44,575 hectares) and 130,000 acres (52,609 hectares), respectively before they were both contained on the 31st.August 9th: Flash flooding in Manitou Springs, Colorado: The burn scar from last year's Waldo Canyon fire made this area of central Colorado susceptible to flash flooding. The flood resulted in one fatality, six houses destroyed and 11 damaged, along with 40 cars stranded and broken gas, sewer, and water pipes. This was the third flash flood in Manitou Springs this year.August (throughout month) Flooding in Las Vegas, Nevada: Several instances of flash flooding occurred this month throughout the greater Las Vegas area impacting travel and damaging roadways.For more information, please go to the Western Regional Climate Center Home Page.

See NCDC's Monthly Records web-page for weather and climate records for the most recent month. For additional national, regional, and statewide data and graphics from 1895-present, for any period, please visit the Climate at a Glance page.

PLEASE NOTE: All of the temperature and precipitation ranks and values are based on preliminary data. The ranks will change when the final data are processed, but will not be replaced on these pages. Graphics based on final data are provided on the Temperature and Precipitation Maps page and the Climate at a Glance page as they become available.


View the original article here

Tuesday, September 17, 2013

2012 was one of the 10 warmest years on record globally

August 6, 2013

State of the Climate in 2012 - report cover.

The 2012 State of the Climate report is available online.

(Credit: NOAA)

Worldwide, 2012 was among the 10 warmest years on record according to the 2012 State of the Climate report released online today by the American Meteorological Society (AMS). The peer-reviewed report, with scientists from NOAA’s National Climatic Data Center in Asheville, N.C., serving as lead editors, was compiled by 384 scientists from 52 countries (highlights, full report). It provides a detailed update on global climate indicators, notable weather events, and other data collected by environmental monitoring stations and instruments on land, sea, ice, and sky. 

“Many of the events that made 2012 such an interesting year are part of the long-term trends we see in a changing and varying climate — carbon levels are climbing, sea levels are rising, Arctic sea ice is melting, and our planet as a whole is becoming a warmer place," said Acting NOAA Administrator Kathryn D. Sullivan, Ph.D. “This annual report is well-researched, well-respected, and well-used; it is a superb example of the timely, actionable climate information that people need from NOAA to help prepare for extremes in our ever-changing environment."

Conditions in the Arctic were a major story of 2012, with the region experiencing unprecedented change and breaking several records. Sea ice shrank to its smallest “summer minimum” extent since satellite records began 34 years ago. In addition, more than 97 percent of the Greenland ice sheet showed some form of melt during the summer, four times greater than the 1981–2010 average melt extent.

Temperature in 2012 compared to the 1981-2010 average.

Temperature in 2012 compared to the 1981-2010 average. Credit: NOAA Climate.gov, based on NCDC data. See more.

The report used dozens of climate indicators to track and identify changes and overall trends to the global climate system. These indicators include greenhouse gas concentrations, temperature of the lower and upper atmosphere, cloud cover, sea surface temperature, sea-level rise, ocean salinity, sea ice extent and snow cover. Each indicator includes thousands of measurements from multiple independent datasets.

Highlights:

Warm temperature trends continue near Earth’s surface: Four major independent datasets show 2012 was among the 10 warmest years on record, ranking either 8th or 9th, depending upon the dataset used. The United States and Argentina had their warmest year on record. La Niña dissipates into neutral conditions:  A weak La Niña dissipated during spring 2012 and, for the first time in several years, neither El Niño nor La Niña, which can dominate regional weather and climate conditions around the globe, prevailed for the majority of the year.  The Arctic continues to warm; sea ice extent reaches record low: The Arctic continued to warm at about twice the rate compared with lower latitudes. Minimum Arctic sea ice extent in September and Northern Hemisphere snow cover extent in June each reached new record lows. Arctic sea ice minimum extent (1.32 million square miles, September 16) was the lowest of the satellite era. This is 18 percent lower than the previous record low extent of 1.61 million square miles that occurred in 2007 and 54 percent lower than the record high minimum ice extent of 2.90 million square miles that occurred in 1980. The temperature of permafrost, or permanently frozen land, reached record-high values in northernmost Alaska. A new melt extent record occurred July 11–12 on the Greenland ice sheet when 97 percent of the ice sheet showed some form of melt, four times greater than the average melt this time of year. Antarctica sea ice extent reaches record high: The Antarctic maximum sea ice extent reached a record high of 7.51 million square miles on September 26. This is 0.5 percent higher than the previous record high extent of 7.47 million square miles that occurred in 2006 and seven percent higher than the record low maximum sea ice extent of 6.96 million square miles that occurred in 1986. Sea surface temperatures increase: Four independent datasets indicate that the globally averaged sea surface temperature for 2012 was among the 11 warmest on record.  After a 30-year period from 1970 to 1999 of rising global sea surface temperatures, the period 2000–2012 exhibited little trend. Part of this difference is linked to the prevalence of La Niña-like conditions during the 21st century, which typically lead to lower global sea surface temperatures. Ocean heat content remains near record levels: Heat content in the upper 2,300 feet, or a little less than one-half mile, of the ocean remained near record high levels in 2012. Overall increases from 2011 to 2012 occurred between depths of 2,300 to 6,600 feet and even in the deep ocean. Sea level reaches record high: Following sharp decreases in global sea level in the first half of 2011 that were linked to the effects of La Niña, sea levels rebounded to reach record highs in 2012. Globally, sea level has been increasing at an average rate of 3.2 ± 0.4 mm per year over the past two decades. Sea ice concentration reached a new record low in mid-September 2012.

Sea ice concentration reached a new record low in mid-September 2012. Credit: NOAA Climate.gov, based on NSIDC data. See more. 

Ocean salinity trends continue: Continuing a trend that began in 2004, oceans were saltier than average in areas of high evaporation, including the central tropical North Pacific, and fresher than average in areas of high precipitation, including the north central Indian Ocean, suggesting that precipitation is increasing in already rainy areas and evaporation is intensifying in drier locations. Tropical cyclones near average: Global tropical cyclone activity during 2012 was near average, with a total of 84 storms, compared with the 1981–2010 average of 89. Similar to 2010 and 2011, the North Atlantic was the only hurricane basin that experienced above-normal activity. Greenhouse gases climb: Major greenhouse gas concentrations, including carbon dioxide, methane, and nitrous oxide, continued to rise during 2012. Following a slight decline in manmade emissions associated with the global economic downturn, global CO2 emissions from fossil fuel combustion and cement production reached a record high in 2011 of 9.5 ± 0.5 petagrams (1,000,000,000,000,000 grams) of carbon , and a new record of 9.7 ± 0.5 petagrams of carbon  is estimated for 2012. Atmospheric CO2 concentrations increased by 2.1 ppm in 2012, reaching a global average of 392.6 ppm for the year. In spring 2012, for the first time, the atmospheric CO2concentration exceeded 400 ppm at several Arctic observational sites. Cool temperature trends continue in Earth’s lower stratosphere: The average lower stratospheric temperature, about six to ten miles above the Earth’s surface, for 2012 was record to near-record cold, depending on the dataset. Increasing greenhouse gases and decline of stratospheric ozone tend to cool the stratosphere while warming the planet near-surface layers.

The 2012 State of the Climate report is peer-reviewed and published annually as a special supplement to the Bulletin of the American Meteorological Society. This year marks the 23rd edition of the report, which is part of the suite of climate services NOAA provides to government, the business sector, academia, and the public to support informed decision-making. The full report can be viewed online.

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter and our other social media channels.


View the original article here

Friday, June 15, 2012

USA had warmest March-May on record

The surreal heat that enveloped much of the USA this spring turned out to be the warmest ever recorded in U.S. history — by an eye-opening margin, scientists report.

University of Illinois freshmen Jill Marik, left, and Jeremy Vivit enjoy unseasonably warm weather on March 13 on the campus Quad in Urbana, Ill. Robert K. O'Daniell, AP

University of Illinois freshmen Jill Marik, left, and Jeremy Vivit enjoy unseasonably warm weather on March 13 on the campus Quad in Urbana, Ill.

Robert K. O'Daniell, AP

University of Illinois freshmen Jill Marik, left, and Jeremy Vivit enjoy unseasonably warm weather on March 13 on the campus Quad in Urbana, Ill.

Coming on the heels of the fourth-warmest winter on record in the USA, nature and the economy were thrown off rhythm, as jobs, retail sales, crops and bugs sprouted outside their normal cycles.

Though the calendar says we're still in spring, climatologists define spring as the months of March, April and May; weather records go back to 1895.

"Record and near-record warmth dominated the eastern two-thirds of the nation during spring," according to the National Climatic Data Center (NCDC) report. "Thirty-one states were record warm for the season. Only Oregon and Washington had spring temperatures near normal."

The spring season's nationally averaged temperature was 57.1 degrees, 5.2 degrees above the long-term average, and surpassing the previous warmest spring (1910) by 2 degrees.

The amount by which the spring broke the record was also phenomenal: Spring 2012 marked the largest temperature departure from average of any season on record in the USA, the center reported.

In addition, the center also announced that the USA is seeing its warmest start to the year since records began.

The warmth wreaked havoc on plants and insects across the country, leading to an unusually early blooming of the cherry trees in Washington, D.C. Apple and peach trees bloomed two months early in the Midwest.

Just Wednesday, the Federal Reserve's Beige Book report on the economy said the warm spring had boosted tourism, bolstering everything from Florida visits by foreigners to ticket sales on Broadway.

Restaurant sales rose by double digits in January and February, months when cold weather keeps many consumers home, helping calm fears that gas prices would slash discretionary spending. Sales of vehicles and parts rose 7.3% in the first quarter, accounting for more than a fourth of the economy's growth, according to the government.

Analysts think car buyers came out earlier than usual this year because dealer lots weren't freezing, said Chris Christopher, an economist at consulting firm IHS Global Insight. And The Home Depot's shares are up 20% this year, largely because of strong winter sales, though momentum at rival Lowe's has cooled since March.

Economists at Moody's Analytics think the warm weather added about 50,000 jobs a month during January and February, Moody's associate economist Sara Kline said. But then the weather has hurt employment growth in recent months given some car, new-house and home-improvement sales happened sooner than expected, both said.

"Workers were brought back more quickly than usual in construction, in trucking and leisure and hospitality than they would be in a normal winter," Kline said. "The flip side is not getting as much growth as expected in March and April."

Too much hot, dry weather can be bad news for agriculture, but it's hard to say how bad the impact this year will be. The Texas economy lost more than $7.6 billion due to last year's heat and drought, said Mark Waller, an agricultural economist at the Texas AgriLife Extension at Texas A&M University.

"It's not as bad as it was last year," because the Texas winter wasn't as dry, he said. "We haven't been hot enough yet this year to damage crops, and we probably got some early hay cutting because it warmed up early."

How warm has it been? Chicago saw eight days in the 80s in March and five days in the 90s in May, the National Weather Service reported, smashing records in a city known for cold, windy weather.

The cause of the strange heat was an ongoing pattern that kept the jet stream much farther to the north than usual, according to NCDC climatologist Jake Crouch. This allowed warm air to spread across most of the country east of the Rockies, he said.

The heat is expected to continue: In its summer forecast released in May, the Climate Prediction Center (CPC) said that about three-fourths of the nation — from the Southwest to the Mid-Atlantic — should see above-average temperatures from June-August.

Additionally, the CPC announced Thursday that there is a 50% chance that El Niño conditions will develop during the second half of the year. El Niño is a periodic warming of sea-surface temperatures in the Pacific Ocean that primarily affects winter weather in the USA.

A typical El Niño tends to bring warmer-than-average winter temperatures to much of the northern USA and cooler-than-average temperatures to the nation's southern tier, the CPC reports.

Worldwide data for spring will be released June 14. Through April, the globe was not experiencing the level of unusual warmth that the USA was: The worldwide temperature for January-April was only the 15th warmest on record, the climate center reported in May.

For more information about reprints & permissions, visit our FAQ's. To report corrections and clarifications, contact Standards Editor Brent Jones. For publication consideration in the newspaper, send comments to letters@usatoday.com. Include name, phone number, city and state for verification. To view our corrections, go to corrections.usatoday.com.

View the original article here

Sunday, May 20, 2012

2012 is USA's warmest year on record, so far

The nation's unusual warmth keeps on rolling: Through April, the USA is experiencing its warmest year on record, the National Oceanic and Atmospheric Administration announced on Tuesday, with a national average temperature of 45 degrees.

This is 5 degrees above the long-term average.

So far this year, more than 15,000 record high temperatures have been set across the nation, compared with about 1,100 record lows, reports Weather Channel meteorologist Guy Walton.

The first four months of 2012 were drier than average for the United States as a whole, with some regional variability, NOAA reported. The eastern third of the nation has been drier than average, with Maryland and Delaware both having their driest year on record, to date.

April itself was the third-warmest on record in the USA, with only April 2006 and April 1981 warmer than this April.

U.S. weather records go back to 1895.


View the original article here

Tuesday, December 6, 2011

Northeast to post warmest November in 10 years (Reuters)

NEW YORK (Reuters) – The Northeastern United States, the world's largest heating oil market, is set to post its warmest November in a decade, and the mildest for some cities like Boston in over 30 years, forecasters said this week.

The Northeast and East North Central regions, including Chicago, Cleveland and St. Louis, had their warmest November since 2001, Pennsylvania-based forecaster Planalytics said.

Boston was the warmest since 1975, while Indianapolis was the warmest in over 50 years.

Overall, forecasters expect this November to be the fifth-warmest since records began in 1950.

The mild weather was a result of "autumn being autumn" and not a sign of a weakening La Nina weather pattern - expected to continue through winter - or a harbinger of what's to come this winter, according to New York-based Weather 2000 meteorologist Michael Schlacter.

While November's mild weather aided U.S. retailers as shoppers took to the streets, it pressured demand for natural gas to fire furnaces and power plants.

Cash gas prices slid to their lowest levels in more than two years, while gas futures on the New York Mercantile Exchange slid to 11-month lows.

Heating oil prices, meanwhile, were weaker, but concerns about supply disruptions due to recent refinery closures limited the downside, market sources said.

The Southwest coast was the coolest since 2004, with Los Angeles the coolest since 2000, the forecaster said.

Weather 2000's Schlacter noted that while New York City had a "warm" November, it was not "off the charts" or historic in nature.

"Even just this past decade we've had some tremendous swings in weather in November temperatures. We're not that much warmer than 2009 or 2006. We are going to top those, but we're still in the same ballpark as the last five years," Schlacter said.

Overall this November will fall behind November 2001, and will likely be the fifth-warmest on recent record, Schlacter said. MDA EarthSat meteorologist Rick Groh agreed.

All the forecasters noted that cooler weather in the U.S. West would likely skew the overall national average.

"The tremendous cool in the West will likely dilute the impressiveness of the warmth for the nation as a whole," Schlacter said.

NOVEMBER VERSUS THE WINTER

Forecasters were quick to note that November weather patterns were not necessarily indicative of how the entire winter will turn out.

Forecaster WSI has called for the mildest winter in five years, lowering heating demand expectations.

U.S. government forecasters said a strengthening La Nina would grip the country for a second straight winter, causing colder and wetter weather in the most northern states and drier, warmer conditions throughout the drought-ravaged South.

The National Oceanic and Atmospheric Administration (NOAA) said it expects the La Nina weather phenomenon that results in cooler ocean temperatures in the Equatorial Pacific, to become the most dominant factor influencing weather across the country, but added that a change in pressure called the Arctic Oscillation could make it difficult for forecasters to predict more than a week or two in advance.

The volatile condition could produce dramatic short-term swings in temperatures. Arctic Oscillation can generate strong shifts in the climate patterns that could overwhelm or amplify La Nina's typical impacts, NOAA said.

Weather 2000 was calling for a below-normal period from December through March for the nation as a whole, with the Ohio Valley and Great Lakes area the focal points of the coolest weather.

"Last year was very impressive. It's probably not going to be as cold as last year, but could be similar to the 2008-2009 winter for the nation as a whole. The winters the last four years have been in that slightly cool direction and that's where we're leaning this year," Schlacter said.

"Chicago, which had a very, very warm November, just like New York, is already starting this new transition. It's a very slow progress and the Interstate-95 corridor on the East Coast is going to have to wait about six or seven days into December until we catch up with that," he said.

"Everything between the Rockies and the Appalachians are doing a 180 flip starting today or yesterday, compared to what was going on in November, which just shows how quickly things can change," Schlacter added.

MDA EarthSat said the December through February winter period would be normal to slightly above-normal for the Northeast and near to slightly-below normal for the Midwest, above-normal in Texas and below-normal on the West Coast and in the Rockies.

(Editing by Andrea Evans)


View the original article here