NOAA Technical Memorandum NWS SR-193, Section 2

2. LIGHTNING REPORT DATA

Reports of damaging weather phenomena are collected monthly by local NOAA-National Weather Service offices. Individual station reports are sent to NOAA's National Climatic Data Center (NCDC) in Asheville, N.C. where Storm Data is assembled for the entire country. This publication has been compiled with essentially the same procedures and agencies since 1959.

The database used in this study contains all reports published in Storm Data. Each report contains the following information:

• Year, month, and day.
• Time in Local Standard Time (LST).
• State and county.
• Number of fatalities.
• Gender and location of fatalities.
• Number of injuries.
• Gender and location of injuries.
• Categorical amount of damage reported.

The total number of lightning-caused reports in the Storm Data archive during the 36 years is in Table 3. A total of 11 casualty or property-damage reports were found to be assigned to the wrong state in the digital database by cross-checking them with the two-letter state codes. The quality of the NCDC database, defined as the ratio of incidents with known time and date of occurrence to all incidents, has improved from below 40% during the 1960s to above 90% after 1987.

Absolute values of the casualties and especially damages in Tables 1 to 3 must be considered with caution. Lightning-caused casualty and damage events are usually less spectacular and more widely dispersed in time and space than are other weather phenomena such as tornadoes and hurricanes. For this reason, lightning deaths, injuries, and damages are underreported, as found in the following studies:

*Mogil et al. (1977) found 33% more lightning deaths in Texas than Storm Data.
*López et al. (1993) found 28% more fatalities and 42% more injuries requiring hospitalization in Colorado than Storm Data.
*Holle et al. (1996) found 367 times as many insured personal property claims due to lightning in three western states than were listed during the same years in Storm Data.
*Lushine (1996) found 31% more fatalities in Florida than Storm Data.

The results of Holle et al. (1996) lead to the conclusion that lightning-caused losses are similar to, or exceed other phenomena in Table 1. When other unquantified losses are taken into account, lightning may be the largest cause of damages and have less change from year to year than most other weather types.

Factors contributing to underreporting include the following:

• Indirect lightning casualties are often reported by the medical system as having lightning as the secondary rather than the primary cause (Mogil et al., 1977).
• Reliance on newspaper clipping services for lightning events entered in Storm Data by the National Weather Service (López et al., 1993).
• The typical lightning casualty usually affects only one individual.

However, the only consistent source of data on lightning deaths, injuries, and damages for several recent decades has been Storm Data. With the exception of 106 damage entries that were miscoded in the year 1989 (Section 12), the Storm Data information will be used in the present report without modification.