A look back at the Williamson County event in 1982 underscores
the vast improvements that have taken place in the past 20 years thanks to
technology. Listed below are several comparisons of technology and
communications in the warning process between 1982 and 2002.
(1.) Believe it or not, the National Weather Service Forecast
Office in St. Louis, Missouri had warning responsibility for Williamson County
back in 1982. In fact, they covered nearly 80 counties across Illinois and
Missouri--all the way down to Cairo, Illinois and the Missouri bootheel!
This alone obviously placed a strain on the staff during warning operations at
the St. Louis office. Created in 1984, the National Weather Service
Forecast Office in Paducah, Kentucky has since acquired warning responsibility
for 58 counties across southeast Missouri, southern Illinois, western Kentucky,
and southwest Indiana. Part of the recent modernization of the National
Weather Service, this shift in warning responsibility has helped to lessen the
workload for the more established offices. For instance, St. Louis now
covers 46 counties--a far cry from what they had 20 years ago!
(2.) Research and technology has also resulted in improved radar
equipment to provide warning forecasters with a clearer picture of potentially
severe storms. Back in 1982, most offices relied on either the WSR-57 or
WSR-74C radars. Today, a network of over 140 WSR-88D (Weather Surveillance
Radar--1988 Doppler) radar sites are strategically positioned at National
Weather Service Weather Forecast Offices and Department of Defense sites across
the United States. For instance, the WSR-88D generates numerous products
from base data and algorithms to assist in identifying the impending severity of
thunderstorms. Besides providing a better picture of storm structure via
reflectivity, the WSR-88D adds the dimension of the Doppler effect to give
forecasters an idea of the motion of air parcels within a thunderstorm.
This allows for the detection of strong mid-level rotation which often precedes
tornado formation. Computer technology also allows for time lapse of radar
data, which clues the forecaster into storm motion and trends. While the Williamson County tornado was over 100
miles from the St. Louis WSR-57 radar back in 1982, the storm would have much
better coverage today from the Paducah WSR-88D, which is only 40 to 50 miles
away.
(3.) The timeliness and resolution of satellite imagery has also
improved since 1982. Twenty years ago, satellite images were taken in
30-minute increments, but were often not available to forecasters until a half
hour later. Today, new GOES (Geostationary Operational Environmental
Satellite) technology provides higher-resolution imagery of thunderstorm
activity. Forecast offices may request rapid scan operation to receive
images in only 7-minute increments during significant weather events.
These pictures are made available to forecasters in the field in a matter of
only 5 to 10 minutes.
(4.) Advancements in communications technology within the past
20 years has made for quicker dissemination of severe weather warnings and
information to those who utilize National Weather Service products. In the
days of AFOS (Automation of Field Operations) and teletype, it was not uncommon
for warnings to take 5 or 10 minutes to reach the intended recipients once the
forecaster decided to issue. Today, computer systems such as AWIPS
(Advanced Weather Interactive Processing System) combined with sophisticated
warning software allow warning forecasters to compose most warnings and
statements in a matter of 1 or 2 minutes. High-bandwidth broadband,
telephone, and satellite communications make it possible for warnings to reach
their intended recipients within mere seconds after dissemination from National
Weather Service offices. Those we serve may choose from a wide variety of
devices to receive our warnings, including NOAA Weather Radio, EMWIN (Emergency Managers Weather
Information Network), NWWS (NOAA Weather Wire Service), the internet, e-mail,
and even such wireless devices as cell phones and pagers!
(5.) Another striking example of improved warning dissemination
is the advancement in NOAA Weather Radio service within the past 20 years.
Back in 1982, the counties now served by WFO Paducah had spotty NOAA Weather
Radio coverage by only four transmitters. Today, eighteen transmitters
provide warning and forecast information for at least part of the WFO Paducah service area.
Today's transmitters are generally more reliable, and most have an automated
monitoring system to alert electronics technicians to potential transmitter or
phone line problems. The recent automation of the NOAA Weather Radio
broadcast allows for simultaneous broadcast of multiple warnings over multiple
transmitters. Furthermore, Specific Area Message Encoding, or SAME coding,
associated with severe weather warnings and statements allows for greater
selectivity in deciding which warnings activate your NOAA Weather Radio receiver
alarm.
(6.) External to the National Weather Service, improved
communications technology has better-equipped the emergency management and law
enforcement communities in disseminating warnings and responding to disasters.
Trained spotters now have a better idea of when and where to concentrate their
efforts. In addition, enhanced computer graphical technologies allow for
quicker dissemination of weather information by local media outlets in an easily
understood format.
Most importantly for all of us, more opportunity exists to
increase public awareness on the dangers of hazardous weather and associated
safety precautions before the next storm strikes.