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Committee Record Assessment

The World Meteorological Organization (WMO) Commission for Climatology (CCl) decided to appoint a Rapporteur on Climate Extremes to keep an official, unbiased list of world weather extremes. Early in 2006, Dr. Randy Cerveny was named the "Rapporteur of Climate Extremes". At a task meeting of the WMO Open Programme Area Group II (OPAG 2) held in Tarragona Spain on August 20-22, 2006, Dr. Cerveny proposed the creation of a world archive for verifying, certifying and storing world weather extremes.

WMO Commission for Climatology agreed that such an archive was useful and necessary. They agreed that a set of procedures should be established such that existing records are verified and made available to the general public and that future weather extremes records are verified and certified. Consequently, they created a Rapporteur for Extreme Records to carry it out. The Rapporteur (currently Dr. Randy Cerveny) will working closely with the CCl Expert Team on Climate Monitoring in the development of the archive.

When a new record extreme has been reported, the Rapporteur initially views the record extreme and determines if an ad hoc extremes committee should be organized. If called, the ad-hoc committee will provide an expert and unbiased recommendation whether the extreme in question should be added to the list. The committee consists of the President of the Commission for Climatology, the Chair of the CCl Open Programme Area Group (OPAG) on Monitoring and Analysis of Climate Variability and Change (the Rapporteur is part of this OPAG), and a representative of the relevant Member State's NMHS as well as experts in the appropriate meteorological phenomenon and observing instrumentation as required. The committee may also consult with a wide variety of additional experts.

The truth be told, world record extremes are mistakenly created all the time. For example a "fat finger" errors such as hand digitizing a 28.0°C as 82.0 would create a world record observation that every quality control system would say was invalid. Additionally, instrumentation problems can generate a report far in excess of the meteorological conditions. But sometimes a combination of fairly extreme meteorological conditions with minor instrumentation problems, such as calibration errors, can necessitate considerable detective work to determine whether a new world record observation was indeed valid or not. Since weather records are often used as indicators that the Earth's climate is changing and/or becoming more extreme, confirmation of new weather extreme records should be recognized as a high priority in the meteorology community.

Many of existing world weather record extremes in the archive are based from past existing record extremes from official sources, e.g., "Climates of the World" (NCDC, US; and "Weather and Climate Extremes" (TEC-0099 US Army Corp of Engineers; As the perception (or the actual occurrence) grows of more frequent extreme weather events, the goal of this database is to archive and verify extreme record events, such as the highest/lowest recorded temperatures and pressures on the Earth, the strongest winds, the greatest precipitation (over different time intervals) as well as records involving the world's most destructive storms, hurricanes and tornadoes. In the past, without the existence of such an official designate to determine and maintain regional or world records of extreme weather events, the critical supportive documentation needed to assess the validity of a weather record event was often hard to find or simply did not exist. Consequently, the CCl Extreme Weather and Climate Archive includes, as much as possible, the metadata, such as date of occurrence, site location, equipment and other factors, associated with the event.

New records and relevant documentation associated with the record extremes will be posted on this website following the Rapporteur's decision.