2015–16 North American winter
Satellite image of the historic blizzard over the Northeast U.S on January 23, 2016.
|
|
| Astronomical winter | December 21 – March 20 |
|---|---|
| Meteorological winter | December 1 – February 29 |
The 2015–16 North American winter refers to winter as it occurred across the continent from late 2015 through early 2016. While there is no well-agreed-upon date used to indicate the start of winter in the Northern Hemisphere, there are two definitions of winter which may be used. Based on the astronomical definition, winter begins at the winter solstice, which in 2015 occurred late on December 21, and ends at the March equinox, which in 2016 occurred on March 20. Based on the meteorological definition, the first day of winter is December 1 and the last day February 29. Both definitions involve a period of approximately three months, with some variability.
On October 15, 2015, the National Oceanic and Atmospheric Administration's Climate Prediction Center issued its U.S. Winter Outlook. The presence of a strong El Niño event was expected to affect weather and climate patterns by influencing the position of the Pacific jet stream. According to CPC deputy director Mike Halpert at the time of the outlook, "A strong El Niño is in place and should exert a strong influence over our weather this winter" and "While temperature and precipitation impacts associated with El Niño are favored, El Niño is not the only player. Cold-air outbreaks and snow storms will likely occur at times this winter. However, the frequency, number and intensity of these events cannot be predicted on a seasonal timescale." Other oscillations anticipated to have some affect on winter in the United States were the Arctic oscillation and the Madden–Julian oscillation. The precipitation outlook indicated an elevated likelihood of above-average levels precipitation from central and southern California to Texas and Florida and northward to southern parts of New England. Above-average precipitation was also favored in southeastern Alaska, with below-average levels of precipitation favored in central and western Alaska, parts of the Northwestern U.S. and northern Rocky Mountain states, and areas in the vicinity of the Great Lakes and Ohio Valley. The temperature outlook favored below-average temperatures in the southern Plains and Southeastern United States. Above-average temperatures were most favored across the West and the northern half of the contiguous United States and Alaska and Hawaii. The drought outlook anticipated improvement in conditions in central and southern California by the end of January 2016, noting the possibility of additional alleviation of drought conditions in February and March. The outlook favored the removal of drought across large parts of the Southwestern U.S., with additional lessening or elimination of drought conditions likely in the southern Plains. Drought conditions were expected to persist across the Pacific Northwest and northern Rocky Mountains, with development likely in Hawaii and areas in the vicinity of the northern Great Lakes region.
...
Wikipedia