Indefinite ceiling

From Glossary of Meteorology
Revision as of 17:12, 25 April 2012 by imported>Perlwikibot
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

indefinite ceiling

(Formerly called ragged ceiling.) After U.S. weather observing practice, the ceiling classification applied when the reported ceiling value represents the vertical visibility upward into surface-based atmospheric phenomena (except precipitation).

Such phenomena include fog, blowing snow, and all of the lithometeors. All indefinite ceilings are estimations, but one of the following must be used as a guide: 1) the distance an observer can see vertically into the obstruction; 2) the height corresponding to the top of a ceiling-light beam; 3) the height at which a ceiling balloon completely disappears; 4) the height determined by the sensor algorithm at automated stations. The letters "VV" (vertical visibility) are used to designate an indefinite ceiling.

Copyright 2022 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact [email protected]. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.