Library Introduction: The following short article was written
for Weather Bureau personnel in late 1947. It provides a glimpse
into the history and philosophy of radar use by the Weather Service
at the beginning of a new age of weather forecasting and weather
observations. Suddenly meteorologists were able to detect atmospheric
phenomena beyond the circle of their vision and predict the arrival
of storms hours in advance merely by glancing at their radar screens.
The installation of the first operational weather radars were landmarks
that began a revolution in the nature of observation and warning
systems used by the Weather Bureau, a revolution that has continued
through the installation of today's NEXRAD Doppler radar systems.
The
Weather Bureau has established a program to install, operate, and
maintain radar equipment in a network of Radar Storm Detection stations.
These are to be located at strategic Weather Bureau stations throughout
the United States. At the present time, however, only four installations
have been established. More stations will be installed as equipment
becomes available. Present radar equipment used by the Weather Bureau
was received from the Navy and is of the airborne type converted
for use in radar storm detection.
The type of equipment now being used is designated AN/APS-2, operating
on a frequency of 3300 megacycles per second, radiating a radio
frequency peak power of 50 kw. Additional sets, it is anticipated,
will be transferred to the Weather Bureau from the Navy Department.
The range of this equipment is slightly over 100 miles. The equipment
is capable of detecting and tracking thunderstorms, frontal activity,
tornadoes, hurricanes, etc.
In the practical operation, observations are made every 2 hours
both during supposedly fair weather and stormy weather. The reason
for an observational program on this time basis in fair weather,
as might be shown on the synoptic chart, is for precautionary purposes
to insure that developments which would otherwise be overlooked
on a spot basis do not go undetected on an areal basis. Radar indicators
will report the description of a storm, will describe whether or
not it is a line or group or a mass type of disturbance. The intensity
of return on the indicators will show whether it is weak, moderate,
or strong. The character of the weather situation is indicated by
the echoes as to whether or not they are scattered or solid. The
tendency is also of importance, showing whether the returns are
decreasing or increasing and whether the echoes are scattered or
becoming strong over the area under observation. The direction and
velocity of movement of the storm is also shown. These items and
others can be grouped in a code denoted as a RAREP, and transmitted
to other stations. Such information as the foregoing makes it possible
to have more accurate 1- to 3-hour short term forecasts, especially
for the telephone service. Of the four installations that have been
made, the first was completed at Washington, D. C., February 14,
1947. The second was completed at Wichita, Kans., May 5, 1947, and
the third was completed at Norfolk, Nebr., August 5, 1947. The final
station at Wichita Falls, Tex., was completed for service use September
23, 1947. Additional installations will be made at other points
throughout the country, as equipment becomes available. The three
midwestern stations form an observational network which can possibly
track nearly any storm within this general area.
At Norfolk, Nebr., it has been reported that protection to the public
interest has more than paid for the installation, in a short period,
in its ability to warn the public of approaching electrical storms,
as in the generation of electricity where it is required that special
precautions must be made to protect a power system supplying cities
in the Elkhorn Valley. Flash flood protection to life and property
in this river basin is another example of radar's use. When sufficient
experience has been gained in the use of this equipment, it is conceivable
that the RAREP can be transmitted on a circuit from Kansas City,
Wichita, Norfolk, Wichita Falls, and Fort Worth, making possible
more effective use by the forecasting centers of the 3 radars in
the Midwest.... [In: Weather Bureau Topics and Personnel October
1947. Pp. 183-184.]
