Statement as of 6:48 AM EST on December 09, 2013
... Pockets of dense fog across the central North Carolina this
Pockets of dense fog will reduce the visibility to just a couple
hundred feet across most of central North Carolina early this
morning. These pockets of dense fog are
sporadic... thus... motorists will encounter rapid fluctuations in
the visibility over a relatively short distance.
Motorists should remain extra alert during their morning
commute... especially near school yards and pedestrian crosswalks.
People who normally cycle... walk or jog for exercise early in the
morning may want to postpone their exercise routine until later
in the day when visibilities should be improved.
Public Information Statement
Statement as of 8:00 am EST on December 9, 2013
***winter weather preparedness week in North Carolina December 8-14,
this week has been declared winter weather preparedness week in
North Carolina. All week long the National Weather Service will be
issuing informative messages to help you prepare for winter weather.
Each day we will cover a different topic. Today we will talk about
the anatomy of winter storms.
Winter weather is the most complex weather phenomena forecasters
face in North Carolina. Winter storms often seem to take on a
chaotic nature as rain turns into sleet, then to snow. It is this
mixture that forecasters contend with many times during the winter
season, as they work to keep the forecast on track and you prepared.
Winter storms bring significant and sometimes rapid changes in the
weather which greatly affects our lives and safety. Winter storms
can develop and last for just a few hours or linger for days. Some
of the worst winter storms in North Carolina producing heavy snow
and ice have trapped people in their cars, and isolated residents in
their homes without utilities and other services for over a week.
Even small amounts of snow and ice can create havoc as residents of
Raleigh Learned on the afternoon of January 19, 2005 when just a
half inch of snow froze onto major highways in the middle of the
day. The freezing of the snow onto the Road surface resulted in
hours of gridlock... stranding many motorists and school buses loaded
with children for hours. Just a little bit of snow in combination
very cold temperatures and the time of day can create dangerous
conditions... crippling major cities.
Winter storms result from a variety of weather patterns. North
Carolina sits in the battleground between cold air from the north
and warm moist air from the south. The timing of the cold air
colliding with moisture streaming in from the Gulf of Mexico and
Atlantic Ocean typically dictates the type of precipitation you see
falling in your backyard. Geography also plays a large role in our
weather. The Appalachian Mountains to the west and the warm waters
of the Gulf Stream just off the coast both play vital roles in
winter storm development. The mountains act to pile up cold air over
the state while the warm waters of the Gulf Stream provide moisture
and lots of energy to winter storms.
The most common and dangerous weather systems which can produce snow
and ice are strong coastal low pressure systems known as
noreasters. Noreasters are low pressure systems which develop over
the ocean and track northeast along the coast. The reason North
Carolina waters are so favorable for noreaster development is due
to the proximity of the Gulf Stream. When cold air rushes out over
the ocean and the Gulf streama very unstable and volatile situation
is created. When this instability combines with the jet stream in
the upper levels of the atmosphere... a massive low pressure system
known as a noreaster can develop. This was the case over ten years
ago in January 2000 when Raleigh received 18 to 24 inches of snow in
less than 24 hours.
Cold air damming typically impacts the central and western portions
of the state. This occurs when cold high pressure over New York and
Pennsylvania pushes cold air south into the Carolinas. This cold air
is heavy and piles up against the mountains as it rushes south. The
mountains act as a dam causing the cold air to deepen across the
Piedmont and sometimes as far east as the coastal plain. When
lighter, warm moist air coming up from the south overruns the cold
air at the surface, freezing rain, sleet and snow can result. This
was the scenario which crippled central North Carolina with an inch
of freezing rain in December 2002.
Winter storms such as these can make driving and walking extremely
dangerous. The aftermath of a major winter storm can have a
devastating impact on a community or an entire region for days,
weeks, or even months. Winter storms are considered to be deceptive
killers because most deaths are indirectly related to the storm.
People die in traffic accidents on icy roads, have heart attacks
while shoveling snow, or succumb to fires or Carbon monoxide while
trying the heat their home improperly.
Additional information on winter weather preparedness can be
obtained on-line through the North Carolina department of emergency
management home Page. The url is:
up-to-date weather information is available on-line from the
following National Weather Service sites serving North Carolina (all
urls in lower case):
NWS Raleigh NC- http://weather.Gov/rah
NWS Wilmington NC - http://weather.Gov/ilm
NWS Newport/Morehead City NC - http://weather.Gov/mhx
NWS Wakefield VA - http://weather.Gov/akq
NWS Blacksburg VA - http://weather.Gov/rnk
NWS Greenville/Spartanburg SC - http://weather.Gov/gsp
National Weather Service winter weather preparedness home Page -