Encyclopedia of Wildfires and Wildland-Urban Interface (WUI) Fires

Living Edition
| Editors: Samuel L. Manzello

Slop Over

  • Jason ForthoferEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-51727-8_180-1



A fire edge that crosses a control line or natural barrier intended to contain the fire.


Slop over is a term used by firefighters to describe a situation when a fire crosses an intended control line or natural barrier. There are several common ways a fire can breach the line or barrier to form a slop over: direct flame contact across the barrier, a short-range spot fire from lofted firebrands, rollout of burning debris, a falling burning tree, or fire spread across the barrier via a small piece of burnable material such as a root, stick, or area of duff. A slop over is differentiated from a spot fire in that a slop over is connected to the main fire while a spot fire is not connected by burned area to the main fire. The designation of a slop over compared to a spot fire would typically be done at the time of discovery of the breach of the fireline. And so a short-range spot fire could go undiscovered and eventually grow to connect to the main...

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Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  1. 1.Missoula Fire Sciences LaboratoryUS Forest Service Rocky Mountain Research StationMissoulaUSA

Section editors and affiliations

  • Sara McAllister
    • 1
  1. 1.USDA Forest ServiceRMRS Missoula Fire Sciences LaboratoryMissoulaUSA