NOAA
forecasters issue U.S. Winter Outlook
National
Oceanic and Atmospheric Administration (NOAA)
Forecasters at
NOAA’s Climate Prediction Center released the U.S. Winter Outlook today, with
La Nina potentially emerging for the second year in a row as the biggest
wild card in how this year’s winter will shape up. La Nina has a 55- to
65-percent chance of developing before winter sets in.
NOAA produces
seasonal outlooks to help communities prepare for what's likely to come in the
next few months and minimize weather's impacts on lives and livelihoods.
Empowering people with actionable forecasts and winter weather tips is key to NOAA’s effort to build a Weather-Ready Nation. EDITOR'S NOTE: Although now, NOAA is forbidden to attribute any of these weather developments to climate change, which is, according to Donald Trump, non-existent. - W. Collette
Empowering people with actionable forecasts and winter weather tips is key to NOAA’s effort to build a Weather-Ready Nation. EDITOR'S NOTE: Although now, NOAA is forbidden to attribute any of these weather developments to climate change, which is, according to Donald Trump, non-existent. - W. Collette
“If La Nina
conditions develop, we predict it will be weak and potentially short-lived, but
it could still shape the character of the upcoming winter,” said Mike Halpert,
deputy director of NOAA’s Climate Prediction Center.
“Typical La Nina patterns during winter include above average precipitation and colder than average temperatures along the Northern Tier of the U.S. and below normal precipitation and drier conditions across the South.”
“Typical La Nina patterns during winter include above average precipitation and colder than average temperatures along the Northern Tier of the U.S. and below normal precipitation and drier conditions across the South.”
Other factors
that influence winter weather include the Arctic Oscillation, which
influences the number of arctic air masses that penetrate into the South and is
difficult to predict more than one to two weeks in advance, and the Madden-Julian Oscillation, which
can affect the number of heavy rain events along the West Coast.
The 2017 U.S. Winter Outlook
(December through February):
Precipitation
Wetter-than-average
conditions are favored across most of the northern United States, extending
from the northern Rockies, to the eastern Great Lakes, the Ohio Valley, in
Hawaii and in western and northern Alaska.
Drier-than-normal
conditions are most likely across the entire southern U.S.
Temperature
Warmer-than-normal
conditions are most likely across the southern two-thirds of the continental
U.S., along the East Coast, across Hawaii and in western and northern Alaska.
Below-average
temperatures are favored along the Northern Tier of the country from Minnesota
to the Pacific Northwest and in southeastern Alaska.
The rest of the
country falls into the equal chance category,
which means they have an equal chance for above-, near-, or below-normal
temperatures and/or precipitation because there is not a strong enough climate
signal in these areas to shift the odds.
Despite the
outlook favoring above-average precipitation this winter, drought is likely to
persist in parts of the northern Plains, although improvement is anticipated
farther West.
Elsewhere,
drought could develop across scattered areas of the South, mainly in regions
that missed the rainfall associated with the active 2017 hurricane season.
NOAA’s seasonal
outlooks give the likelihood that temperature and precipitation will be above-,
near, or below-average, and also how drought is expected to change, but do not
project seasonal snowfall accumulations.
While the last
two winters featured above-average temperatures over much of the nation,
significant snowstorms still impacted different parts of the country. Snow
forecasts are generally not predictable more than a week in advance because
they depend upon the strength and track of winter storms. The U.S. Winter
Outlook will be updated on November 16.