Severe Thunderstorm and Tornado Warnings at Raleigh, North Carolina

Severe Thunderstorm and Tornado Warnings at Raleigh, North Carolina The National Weather Service issues public warnings for severe thunderstorms and tornadoes when these storms appear imminent. A study of the warning process was conducted at the National Weather Service Forecast Office at Raleigh, North Carolina, from 1994 through 1996. The purpose of the study was to examine the decision process by documenting the types of information leading to decisions to warn or not to warn and by describing the sequence and timing of events in the development of warnings. It was found that the evolution of warnings followed a logical sequence beginning with storm monitoring and proceeding with increasingly focused activity. For simplicity, information input to the process was categorized as one of three types: ground truth, radar reflectivity, or radar velocity.Reflectivity, velocity, and ground truth were all equally likely to initiate the investigation process. This investigation took an average of 7 min, after which either a decision was made not to warn or new information triggered the warning. Decisions not to issue warnings were based more on ground truth and reflectivity than radar velocity products. Warnings with investigations of more than 2 min were more likely to be triggered by radar reflectivity, than by velocity or ground truth. Warnings with a shorter investigation time, defined here as immediate trigger warnings, were less frequently based on velocity products and more on ground truth information. Once the decision was made to warn, it took an average of 2.1 min to prepare the warning text. In 85 of cases when warnings were issued, at least one contact was made to emergency management officials or storm spotters in the warned county. Reports of severe weather were usually received soon after the warning was transmittedalmost half of these within 30 min after issue. A total of 68 were received during the severe weather episode, but some of these storm reports later proved false according to Storm Data.Even though the WSR-88D is a sophisticated tool, ground truth information was found to be a vital part of the warning process. However, the data did not indicate that population density was statistically correlated either with the number of warnings issued or the verification rate. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Bulletin of the American Meteorological Society American Meteorological Society

Severe Thunderstorm and Tornado Warnings at Raleigh, North Carolina

Loading next page...
 
/lp/ams/severe-thunderstorm-and-tornado-warnings-at-raleigh-north-carolina-HQ3WLXuV0S
Publisher
American Meteorological Society
Copyright
Copyright © American Meteorological Society
ISSN
1520-0477
D.O.I.
10.1175/1520-0477(1997)078<2559:STATWA>2.0.CO;2
Publisher site
See Article on Publisher Site

Abstract

The National Weather Service issues public warnings for severe thunderstorms and tornadoes when these storms appear imminent. A study of the warning process was conducted at the National Weather Service Forecast Office at Raleigh, North Carolina, from 1994 through 1996. The purpose of the study was to examine the decision process by documenting the types of information leading to decisions to warn or not to warn and by describing the sequence and timing of events in the development of warnings. It was found that the evolution of warnings followed a logical sequence beginning with storm monitoring and proceeding with increasingly focused activity. For simplicity, information input to the process was categorized as one of three types: ground truth, radar reflectivity, or radar velocity.Reflectivity, velocity, and ground truth were all equally likely to initiate the investigation process. This investigation took an average of 7 min, after which either a decision was made not to warn or new information triggered the warning. Decisions not to issue warnings were based more on ground truth and reflectivity than radar velocity products. Warnings with investigations of more than 2 min were more likely to be triggered by radar reflectivity, than by velocity or ground truth. Warnings with a shorter investigation time, defined here as immediate trigger warnings, were less frequently based on velocity products and more on ground truth information. Once the decision was made to warn, it took an average of 2.1 min to prepare the warning text. In 85 of cases when warnings were issued, at least one contact was made to emergency management officials or storm spotters in the warned county. Reports of severe weather were usually received soon after the warning was transmittedalmost half of these within 30 min after issue. A total of 68 were received during the severe weather episode, but some of these storm reports later proved false according to Storm Data.Even though the WSR-88D is a sophisticated tool, ground truth information was found to be a vital part of the warning process. However, the data did not indicate that population density was statistically correlated either with the number of warnings issued or the verification rate.

Journal

Bulletin of the American Meteorological SocietyAmerican Meteorological Society

Published: Nov 1, 1997

There are no references for this article.

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve Freelancer

DeepDyve Pro

Price
FREE
$49/month

$360/year
Save searches from
Google Scholar,
PubMed
Create lists to
organize your research
Export lists, citations
Read DeepDyve articles
Abstract access only
Unlimited access to over
18 million full-text articles
Print
20 pages/month
PDF Discount
20% off