A Major Winter Storm is Moving Up the East Coast- How is it Monitored and Forecast?
Have you ever wondered how the National Weather Service can tell a
major winter storm is brewing and will impact your area in the coming
days or hours? How can meteorologists tell if a storm is intensifying
and where it will bring the most snow? It's a highly sophisticated process.
It all starts with observing the current situation. The National Weather
Service operates a widespread network of observing systems such as geostationary
satellites. Doppler radars, and automated surface observing systems
that feed into the current state-of-the-art numerical computer models
to provide a glimpse of what will happen next - ranging from hours to
days. The models are then analyzed by NWS meteorologists who use their
experience and expertise to write and disseminate forecasts.
Las Vegas, February 23-24, 2004 (Photo by David Thornburg) |
Winter Weather Watches, Warnings and Advisories- What do they all Mean?
The National Weather Service uses specific winter weather terms
to ensure that people know what to expect in the coming days
and hours . A Winter Storm Watch means
that severe winter conditions, such as heavy snow and/or ice,
may affect your area, but its occurrence, location and timing
are still uncertain. A winter storm watch is issued to provide
12 to 48 hours notice of the possibility of severe winter weather.
A winter storm watch is intended to provide enough lead time
so those who need to set plans in motion can do so. A watch is
upgraded to a Winter Storm Warning when hazardous winter weather in the form of heavy snow, heavy freezing rain, or heavy sleet is imminent or occurring. Winter Storm Warnings are usually issued 12 to 24 hours before the event is expected to begin. Winter Weather Advisories inform
you that winter weather conditions are expected to cause significant
inconveniences that may be hazardous. If caution is exercised,
advisory situations should not become life-threatening. A Blizzard
Warning means that snow and strong winds
will combine to produce a blinding snow (near zero visibility),
deep drifts, and life-threatening wind chill. Be sure to listen
carefully to the radio, television, and NOAA Weather Radio for
the latest winter storm watches, warnings, and advisories. A complete listing of winter weather terms and definitions of watches, warnings, and advisories is available
Why is Predicting the Exact Amount of Snowfall So Challenging?
Snow forecasts continue to improve, but they remain a challenging
task for meteorologists. Heavy snow often falls in small bands
that are hard to discern on larger resolution computer models.
In addition, extremely small temperature differences define the
boundary line between rain and snow.
Will the approaching storm bring heavy snowfall to your
area?
Each winter, meteorologists at the Hydrometeorological Prediction Center, monitor weather data from across the
nation for developing areas of heavy snow and freezing precipitation within weather systems. Their ability to
provide additional information about developing situations enhances
winter storm warnings and helps National Weather Service field
offices, private industry and local governments improve preparedness.
For instance, a prediction of eight inches of snow carries much
greater consequences for a city's rush hour than four inches.
Are you Prepared for Winter Weather?
Winter weather too often catches people unprepared. Researchers
say that 70 percent of the fatalities related to ice and snow
occur in automobiles, and about 25 percent of all winter related
fatalities are people that are caught off guard, out in the storm.
Getting the Latest Winter Weather Information
There is no better way to keep ahead of a winter storm
than with NOAA Weather Radio (NWR), a small receiver device that
can be purchased at many electronic stores. As the "Voice of
the National Weather Service," it provides continuous broadcasts
of the latest weather information from local National Weather
Service offices. The NWR network has more than 425 stations,
covering all 50 states, adjacent coastal waters, Puerto Rico,
the U.S. Virgin Islands, and U.S. Pacific Territories. Weather
radios come in many sizes, with a variety of functions and costs.
The NWR network has been further advanced by the implementation
of Specific Area Message Encoding (SAME) technology. The SAME
allows the user to receive warnings only for their specific location.
SAME receivers are a live-saving tool, providing audible alert
tones for any weather warnings. A NOAA Weather Radio is a useful
and potentially life-saving gift idea this holiday season.
What is Wind Chill?
One of the gravest dangers of winter weather is wind chill.
The wind chill is based on the rate of heat loss from exposed
skin by combined effects of wind and cold. As the wind increases,
heat is carried away from the body at an accelerated rate, driving
down the body temperature. Animals are also effected by wind
chill. Check
out the wind chill chart.
NOAA's Snow and Ice Center
The National Snow and Ice Data Center (NSIDC) serves as
the national information center that supports research in glaciers
and freezing weather phenomenon. The NSIDC archives snow and
ice data, and maintains information about everything from avalanches
to icebergs. The NSIDC web site contains
a fascinating list of
Questions and Answers about snow that are
sure to be of interest to anyone experiencing winter weather.