This table shows, for Cape Canaveral Air Force Station in Florida and Vandenberg Air Force Base in California, launches scrubbed (cancelled) during designated time periods because of Lightning Launch Commit Criteria violations. (The data were separately compiled at the weather offices of the two ranges.)
The nature of triggered lightning leads to a paradoxical situation in which the criteria have a greater impact on launches in California, where the threat of natural lightning is minimal, than in Florida, where it is maximal. The table shows that the most scrubs in Florida occurred for developing cumulus clouds, while the most in California occurred for layered clouds. Electric fields aloft are not monitored by either range prior to a launch, and surface electric fields are monitored only in Florida.
| Lightning hazard mentioned in LLCC* | ELV** scrubs in Florida (11/87–3/94) |
Scrubs in California (2/88–10/98) |
|---|---|---|
| Active thunderstorms | 1 | 2 |
| Cumulus clouds | 15 | 5 |
| Anvil clouds | 0 | 0 |
| Debris clouds | 5 | 0 |
| Disturbed weather | 2 | 4 |
| Thick cloud layers | 5 | 9 |
| Smoke plumes | 0 | 1 |
| Surface electric fields | 6 | n/a |
| Electric fields aloft | n/a | n/a |
* Lightning Launch Commitment Criteria ** Expendable Launch Vehicle | ||