warmest snow less april  כיסויי השלג הנמוך ביותר באפריל החם ביותר

אפריל האחרון היה החם ביותר מאז שיש מדידות
ובמקביל ולא מאוד מפתיע כסוי השלג באמריקה הצפונית היה הנמוך ביותר מאז שהתחילו המדידות

Winter 2009-2010 was much colder than normal for the United States, and it delivered a string of record-breaking snowstorms that began on the winter solstice.
The snow and cold didn’t linger far into the spring, however. By the end of April, North American snow cover had retreated to the lowest extent in the 1967–2010 record, according to the National Oceanic and Atmospheric Administration’sApril 2010 State of the Climate Report. This map shows percent snow cover across North America in April 2010 based on observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Percent snow cover ranges from just above zero (light blue) to 100 percent (white). Land areas with no detectable snow cover during the month are gray.
According to NOAA, “Across North America, snow cover for April 2010 was 2.2 million square kilometers below average—the lowest April snow cover extent since satellite records began in 1967 and the largest negative anomaly to occur in the 521 months that satellite measurements are available.” Unusual warmth descended on North America in April, leading to both low snowfall amounts and rapid melt of existing snow.
The Earth Observatory’s Global Maps section provides an animation of monthly,global snow cover from February 2000 to the present.
NASA Earth Observatory image by Jesse Allen, based on MODIS snow cover data available through the NASA Earth Observations (NEO) Website. Caption by Rebecca Lindsey.
Terra - MODIS
מעניין אם הידיעה הזאת זוכה לכיסויי שווה לידיעות על השלג הרב מוקדם יותר השנה

May 17, 2010
Each month NOAA’s National Climatic Data Center (NCDC) releases two assessments, one national and one global, of the previous month’s climate. These reports include information on the temperature and precipitation levels experienced nationally and globally, providing useful information about these important climate variables in historical perspective. The reports also chronicle any significant weather and climate-related events that occurred during the month.  This trusted source of information is used globally by industry and business, government agencies, academia, and members of the public to help inform decision making.
Animation of global April temperature amomalies; global January - April temperature amomalies; and snow cover extent (December 2009 - April 2010).
Animation (Credit: NOAA)
Summary Figures from the Global Report
The global report is a monthly snapshot of the climate system around the globe that informs the public of the current state of the global climate and helps planners, academics and sector users factor the climate’s current state and recent trends into their decision making. The report details the average global land temperature, the average global ocean temperature, and the combined average of the two. Instead of using raw temperatures, the report presents temperature anomalies, which means the difference from average temperatures for any given area over a period of time. Using anomalies allows for a more accurate understanding of temperature trends over space and time, even with some fluctuations in data availability (see additional information below).
April 2010 Global Temperature Anomalies
High resolution (Credit: NOAA)
This figure depicts all the global surface temperature anomalies for the month of April from 1880 to 2010.
  • The global land and ocean temperature during April 2010 was the warmest on record, surpassing the previous record set in 1998.
  • The warmest anomalies during April 2010 occurred in southern Asia, northern Africa, the north central and northeastern U.S., Canada, Europe, and parts of northern Russia.
  • Cooler-than-average conditions prevailed across Argentina, Mongolia, eastern and southern Russia, and most of China.
  • This was the 34th consecutive April with average global surface (land + ocean) temperatures above the 20th century average.
    • The last April with below average temperatures occurred in 1976.
  • April 2010 was the 302nd consecutive month with average global surface (land + ocean) temperature above the 20th century average.
    • The last month with an average global surface (land + ocean) temperature below the 20th century average was February 1985.
  • Although temperature anomalies across the equatorial Pacific Ocean remained above 0.5°C (0.9°F), El Niño weakened during April 2010. According to NOAA's Climate Prediction Center (CPC), a transition to El Niño Southern Oscillation (ENSO) neutral conditions is expected by June 2010 and to continue into the Northern Hemisphere summer 2010.
  • According to Beijing Climate Center, China experienced its coolest April since 1961. Liaoning, Jilin, and Shandong had their coolest April on record. Hebei, Anhui, and Jiangsu had their second coolest April since records began in 1951.
  • Based on NOAA satellite observations, snow cover extent was the fourth-lowest (fourth-smallest snow cover footprint) on record (since 1967), and below the 1967-2010 average for the Northern Hemisphere, for the seventh consecutive April. Warmer-than-normal conditions over North America, Europe, and parts of Russia contributed to the small snow footprint. These data are compiled at the Rutgers Snow Laboratory, a NOAA-sponsored facility.
  • The North American snow cover extent for the month was the smallest on record for April. It was also the largest negative anomaly, meaning distance below the long-term average, on record for any month.
    • The Northern Hemisphere land-and-ocean temperature were the warmest April on record,
    • The Southern Hemisphere land-and-ocean temperature during April 2010 was second warmest, behind 1998.
    • The tropics (20˚N-20˚S) land-and-ocean temperature tied with 1998 as the warmest April on record.
Year –to-Date (January – April) 2010 Global Temperature Anomalies
This figure depicts the global surface temperature anomalies for the period of time from January to April 2010. The temperature is compared to the average global temperature from 1971-2000.
High resolution (Credit: NOAA)
  • Temperature anomalies for the first four months of the year were anomalously warm over much of the world’s surface, especially so in Canada, northern Africa, South Asia and the vast majority of the tropics.
  • Cooler-than-average conditions prevailed across the higher-latitude southern oceans, the Gulf of Alaska, along the western South American coast, Mongolia, northern China, the southern U.S., northern Mexico, and much of Europe and Russia.
  • The Northern Hemisphere land and ocean temperature during January-April 2010 was the third warmest on record.
  • The Southern Hemisphere land and ocean temperature were second warmest such period, behind 1998.
  • The tropics (20˚N-20˚S) land and ocean temperature during January-April 2010 were also the second warmest on record, behind 1998.
  • January-April 2010 global average temperatures were the warmest on record.
  • The global land surface temperature during January-April 2010 ranked as the third warmest on record, behind 2007 (warmest) and 2002 (second warmest).
  • The global ocean surface temperature during January-April 2010 was second warmest, behind 1998.
  • January-April 2010 was the 34th consecutive year with above average temperatures. The last January-April with below average temperatures occurred in 1976.

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