Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 47
4
Guidelines for Assessing Possible Degradation
of Service in Specific Areas
The pane! conducted an assessment of the adequacy of NEXRAD coverage for the nation in
terms of the "no degradation of service" requirement imposed by the Weather Service Modernization
Act. Accordingly, the pane} examined the relative capabilities of the pre-NEXRAD and NEXRAD
systems on a national level. In the course of this analysis the pane! identified some geographic areas
where there appears to be a potential for degraded radar-detection coverage with the new system.
However, the pane! deliberately did not attempt to make specific determinations as to the possible
degradation of service at particular locations; nor did it conduct a site-by-site investigation of the possi-
ble need for additional radars.
As discussed in previous sections, service is a much more complex and subjective matter than
radar-detection coverage. Many factors, apart from technical considerations, enter into decisions
regarding the need for additional radars, including budgets, congressional interests, pressure from the
public, and similar input. It is beyond the panel's purview to make such determinations; however, these
factors, as well as economic vulnerability and impacts, are important and should be considered by the
NWS. The pane! recognizes that the NWS will be pressed to make such determinations with regard
to specific sites as the modernization progresses. The public concerns discussed in the following section
reflect these kinds of site-specific issues. A set of general criteria are provided in Chapter 4 under
"Assessment Criteria and Procedures." These criteria can be used to assess possible degradation of
service in particular locations and to determine whether additional radars are warranted.
CONSIDERATION OF PUBLIC CONCERNS
Concern about possible degradation of services in the course of the NWS modernization program
has generated considerable public comment. In accordance with a Federal Register announcement of
November 4, 1994, the NWS received comments from approximately 67,000 people in the form of
letters, postcards, collections of information, and signatures on resolutions and petitions. About 65,000
of these people (largely from 3 areas) signed petitions or sent form postcards as part of organized
efforts to obtain additional NEXRAD coverage for their communities. In contrast, of the approximately
1,800 individually formulated letters and postcards, most (90 percent) commented on the need for
continued services from their local weather office. About 10 percent provided technical data or other
information about deficiencies in radar coverage that might be encountered when an existing radar was
decommissioned and the coverage for an area would be provided by a NEXRAD relatively distant
(usually 80 or more miles) from their community. Figure 4-! shows-the 32 areas of the nation from
which public comments were received. Comments from 15 areas (solid circles) were concerned
primarily with Me planned closure of a local weather office. The other 17 areas (~e open circles and
47
OCR for page 48
o ~o
is
to fat
l ok
l o:
- -
- -
o ~
no ~-7 =~y
ad ~ok t
~o
·o ~
CQ
a, ~
q - o
o ~
~ o
c,
~ -
~ A)
ID O
~ o
·=
i,
3
~ o
~ DO
o
os o
To ~
1 Ce
.
.q
o
_9a-
_)
48
04
a
O
.~
e
Rae
·3
o
o
I::
._
·t
o
o
._
as
~4
1' ~ ~ is,
V I. O
~ o
~ o o
~ c ~
~ ~ ,E
~, CL
°
C t\' C
~, C
C' ° ~
1 1
O -
OCR for page 49
Guidelines for Assessing Possible Degradation
49
the hatched area) were concerned about radar coverage or about both radar coverage and office
closure. The NWS forwarded the comments to the NRC for use by the NEXRAD panel. Technical
information included in the public comments was incorporated into the panel's analyses and was
considered during He course of the study.
ASSESSMENT CRITERIA
The panel's charge included the task of "establish[ing] criteria for evaluating the adequacy of
coverage of Be pre-NEXRAD and the proposed NEXRAD network and areas for decommissioning
of existing radars." In response to this task, the panel recommends the following criteria and
procedures for use in evaluating the adequacy of NEXRAD coverage for specific areas.
The suggested evaluation criteria are as follows:
I. Weather phenomena of concern to the area Are the weather phenomena of concern
detectable by weather radar?
2. Degradation of radar coverage relative to the weather phenomena of concern- Do the
radar-detection coverage maps for specific weather phenomenon show degraded
coverage by NEXRAD?
Performance of the composite system relative to the phenomena of concern-Does the
composite system evaluation indicate that the new system performs as well as the old
system?
The suggested evaluation procedures are as follows:
I. Determine the weather phenomena of concern in the area of interest.
2. Examine the relevant weather phenomena radar coverage maples) to identify regions
where radar coverage of each phenomenon is reduced from what had existed with the
pre-NEXRAD system.
3. Assess the composite system capability and its impact; especially on reducing the risk
to life and property. The composite system elements include, but are not limited to,
those listed below.
characteristics of local weather phenomena;
radar coverage and terrain features;
data quality and availability;
· local spotter network and the user community;
adequacy of communications within the composite system and with users;
education and training for the forecasters and user community; and
· other composite system elements, such as ASOS, satellite data, soundings, prior
RADAP IT and/or ICRAD capability, AWIPS, centralized support products and
services, and similar elements.
If an assessment of composite system performance and its consequences concludes that services
related to radar coverage would be degraded, then there is inadequate radar coverage for the area.
Wherever Were is inadequate radar coverage, the NWS should take appropriate actions to reduce the
risk of adverse weather consequences to human life and property to acceptable levels. One of the
options would be to determine the cost and benefits of providing the needed detection coverage for the
area of concern by adding or relocating a NEXRAD or by using some other radar alternative.
OCR for page 50
so
Assessment of NEXRAD Coverage
The detection coverage charts for specific weather phenomena Mat were developed by the panel,
along with the suggested assessment criteria and procedures, provide a baseline for the NWS (or
others) to make decisions on the adequacy of NEXRADs to meet the coverage and service requirements
for specific areas. The panel's assessment criteria and procedures should be incorporated into official
NWS guidelines and used in conjunction wig the requirements in P.~. 102-567.~
~ The certification criteria for decommissioning an existing radar and consolidating weather offices were
published in the Federal Register, Vol. 59, No. 41, March 2, 1994, "Rules and Regulations." These criteria
included formal actions that certify and commission the supporting NEXRAD, provide adequate notification to users,
provide user confirmation of associated services, and determine that the existing radar is no longer needed for
service coverage of that area.
Representative terms from entire chapter:
weather phenomena
