The
Climate Prediction Center (CPC) released its latest outlook for the coming
winter this morning. This year’s
forecast is challenging as there are few climate signals that are strong enough
to give clues as to what to expect. Thus
the outlook is based more on trends.
Climate
outlooks are probabilistic forecasts meaning that they give you information about
the chances of seeing departures from the average. It cannot tell you when or where snowstorms
will occur. The outlook is designed to
tell you what the average conditions will be.
This
year warmer than normal conditions are expected for the Southwest, the
South-Central U.S., parts of the Southeast, New England and western Alaska. The Northern Plains and the Alaskan Panhandle
are expected to see colder than normal conditions. South Carolina has an equal chance of seeing warmer,
near normal, or colder conditions as there are no clues to guide the forecast.
 |
| The temperature outlook for the 2013-14 winter. Click on the image for a larger view. Image Credit: NOAA. |
The
bigger story this winter may be a developing drought for South Carolina as drier
than normal conditions are more likely.
This follows on the heels of a warm, dry fall and a cool, wet
summer. Incipient drought conditions are
already developing in some parts of South Carolina and a dry winter will only
make it worse. This could lead to low
soil moisture for spring planting and an increase wildfire danger by late
winter.
 |
| The precipitation outlook for the 2013-14 winter. Click on the image for a larger view. Image Credit: NOAA. |
Drought
conditions are expected to worsen over the Southwest and parts of the southern
Plains. This is an area that has been
battling drought for the last three years and that is not expected to change in
the near future.
Climate
outlooks often key off of climate influences like El Nino – La Nina. Mike Halpert, acting director of NOAA’s
Climate Prediction Center, had this to say to say about the lack of these
signals:
“It’s a challenge to produce a long-term winter forecast without the climate pattern of an El Niño or a La Niña in place out in the Pacific because those climate patterns often strongly influence winter temperature and precipitation here in the United States. Without this strong seasonal influence, winter weather is often affected by short-term climate patterns, such as the Arctic Oscillation, that are not predictable beyond a week or two. So it’s important to pay attention to your local daily weather forecast throughout the winter.”
The
Arctic Oscillation has two phases, positive or negative. A negative phase allows cold arctic air to
slide south into the U.S. and can put the country in a deep freeze depending on
the strength of the phase. A positive
phase has the opposite effect and can result in warmer than normal
conditions. The record warm March of
2012 was an example of the positive phase for an extended period.
South
Carolina has experienced wild swings in temperatures over the past week related
to the Arctic Oscillation and this is likely to continue for the rest of
November into December. This means that
cold waves will periodically invade followed by warmer periods. It will be a roller coaster temperature ride
into early winter.
Warmer
than normal conditions are expected for South Carolina next spring with equal
chances of wet or dry conditions. This
could favor an early spring and an active pollen season. Research indicates that pollen counts have
been increasing recently due to warmer springs.
The spring of 2012 saw record pollen counts over much of the Southeast. However, the weather may be quite variable
which may not be conducive to early planting.
Here
is a video from Climate.gov on the winter outlook for this year:
