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<br />Q. How accuratel.y do you think you'll he able to translate the
<br />D/RADEX return into inches of rainfall?
<br />
<br />A. That remains to be seen. There have been a lot of tests. I sup-
<br />pose that we will be able to come within, say, an inch or two with a
<br />six-inch deluge. We are confident that D/RADEX, when perfected,
<br />will allow us to give much better warnings. We will be able to
<br />measure and keep track of heavy rainfall as it is occurring and con-
<br />sequently issue fla~h-flood warnings much sooner and more pre-
<br />cisely than is now possible.
<br />
<br />Q. Any other new techniques to speed warnings?
<br />
<br />A. Yes. We have a new automatic flash-flood sensor. The first of
<br />these went into place near Wheeling, 'Vest Virginia, this spring,
<br />Others are being installed elsewhere in the East this year. Ten of
<br />them have been funded; at least that many more may be forthcom-
<br />ing. These are float-type devices-like a bulb in a toilet tank-that
<br />you mount on a bridge abutment or some other spot where rising
<br />water will affect it, so that a flash flood will activate an electrical
<br />signal. This signal is carried by connecting circuitry several miles
<br />downstream to sound a buzzer or set off a flashing light in a police
<br />or fire station-someplace manned 'round-the-clock. From here
<br />warnings can be passed to the public by means of radio and TV or
<br />possibly by siren.
<br />This is a cooperative program. The Weather Service pays for
<br />the water-level sensor, and the audio or visual alarm system, and
<br />their maintenance: the local community pays utility costs.
<br />
<br />Q. How much does such a system cost, for equipment and installa~
<br />tion?
<br />
<br />A, Roughly S3,OOO.
<br />
<br />Q. 'Viii NOAA's new Geostationar)' Operational Environmental
<br />Satellite, slated for launch late in 1973, help :you in transmitting
<br />flash~nood communications?
<br />
<br />A. Indeed it will help us improve ftashwftood communications. Al-
<br />though the primary mission of GOES will be indirect sensing of
<br />electromagnetic radiation in the visible and infrared ranges-map-
<br />ping and picturewtaking functions-it will also serve as a data-.relay
<br />satellite-passing along weather information from stations anywhere
<br />within its field of view. It should be able to interrogate -and pass on
<br />data from as many as 10,000 stations, including rain and river gages,
<br />buoys, ships, aircraft, and perhaps balloons.
<br />
<br />Q. How will it be better than existing communications systems?
<br />
<br />A. It will be most useful to us at first in rugged, mountainous areas
<br />such as the Columbia Basin in the Pacific Northwest, where the
<br />initial GOES network will be established. In such areas, land lines
<br />are difficult to maintain or nonexistent, and the radio frequencies we
<br />have been assigned to lIse are extremely expensive to operate because
<br />the signals travel by line of sight, requiring frequent relay stations.
<br />
<br />Q. Could you elaborate on that a bit?
<br />
<br />A. Well, you will start with an automated rain gage or river gage,
<br />the same sensing equipment we now interrogate by telephone. When
<br />using GOES, instead of sending the signal horizontally through a wire
<br />or by radio relays, you will have the sensor radio it up to the satellite,
<br />which will relay it back down to the receiving station at Wallops
<br />Island, Virginia. The signal will then go over existing land lines of
<br />the Weather Service to our forecast offices needing the data. Instead
<br />of having perhaps J 0 or 15 radio. relay stations passing the signal
<br />along over rugged terrain, you will have just one relay station-that
<br />is, the satellite.
<br />It will be seeing 48 states and southeastern Alaska.
<br />
<br />Q. How man)' relay stations on the ground will the satellite save,
<br />all told?
<br />
<br />A. Well, the question is hypothetical because you wouldn't install
<br />on the surface all the land-line and relay-station capability the satel-
<br />lite could provide. But some existing radio networks of this type in
<br />rugged terrain have just about as many relays as sensors. So with
<br />1,000 observing stations you might have 1,000 relay stations. The
<br />satellite would take the place of all but one of the latter.
<br />
<br />Q. Then the satellite will let )"ou do things that were out of the
<br />question before because of the cost-right?
<br />
<br />A. Yes, but bear in mind that the main function of GOES will be
<br />viewing global weather patterns. The data-relay capability becomes
<br />available at relatively little increase in cost. The satellite, from its
<br />fixed position 22,300 miles high over the Equator, will provide fore-
<br />casters with a steady stream of cloud photographs all a real-time
<br />basis, day and night. This will greatly enhance our ability to spot,
<br />track, and forecast the growth and movement of severe storms which
<br />may produce heavy rainfall.
<br />
<br />Q. With these sophisticated devices coming along, how do you
<br />,'isualize the ftash.ftood warning s)'stem of the future? How good will
<br />it be?
<br />
<br />A. We should be able to issue detailed flash-flood forecasts in situa-
<br />tions where now we can isslle only flash-flood warnings some hours
<br />after the water is on the ground. We should be able to do this within
<br />an hour after a heavy rainfall ha'i occurred-being very specific
<br />about just who, up and down the slope, will be affected, and just how
<br />high the water will rise. Instead of a generalized warning that there is
<br />high water coming, over a large area, people will be told whether it
<br />is really going to affect them. Improved technology will let us narrow
<br />the warning to those actually involved.
<br />
<br />Q. Cooperative efforts by the communities involved ,,,.i11 continue
<br />to be important, won't they?
<br />
<br />A. Yes, they will. These cooperative programs are already doing a
<br />good job.
<br />
<br />Q. How do these l'ooperath;e s)'stcms work? How many arc there?
<br />
<br />A. Right now, even without a lot of sophisticated new equipment,
<br />there are 138 flash-flood warning systems in the U.S. that make use
<br />of a combination of Federal and local personnel to issue warnings.
<br />Some of these go back almost 20 years, and resulted from early work
<br />we did with the American Red Cross. Most of them came into being
<br />after a bad flood. Many of these cooperative systems make use of
<br />rainfall and streamflow observers at key points who telephone their
<br />observations to a central location, From these, high water can be
<br />forecast downstream, based on previous calculations.
<br />
<br />Q. How does a community go ahout arranging for such a s}'stem?
<br />
<br />A. We can arrange for them to get copies of typical plans now in
<br />existence. Canton, Ohio, has a good one. It includes radar surveillance
<br />and telemetered rain gages. It has been in operation for 10 years.
<br />
<br />Q. Do you believe there should be a lot more such systems?
<br />
<br />A. There undoubtedly are many, many more places which would
<br />benefit from flash-flood warning systems. Certainly, \Vest Virginia
<br />could use more, and other mountainous areas, too. Resort and vaca-
<br />tion areas in some states could use them. Streamside campers are
<br />often caught unaware. There have been several such incidents with
<br />heavy loss of life, especially one in Arizona in September 1970, when
<br />23 people were drowned, most of them campers.
<br />
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