Editing IPCC:AR6/WGI/Chapter-11 (section)

=== Extreme Storms, Including Tropical Cyclones ===

<div id="h2-6-siblings" class="h2-siblings"></div>

'''The average and maximum rain rates associated with tropical cyclones (TCs), extratropical cyclones and atmospheric rivers across the globe, and severe convective storms in some regions,''' '''increase in a warming world''' ( ''high confidence'' ''')''' ''.'' Available event attribution studies of observed strong TCs provide ''medium confidence'' for a human contribution to extreme TC rainfall. Peak TC rain rates increase with local warming at least at the rate of mean water vapour increase over oceans (about 7% per 1°C of warming) and in some cases exceeding this rate due to increased low-level moisture convergence caused by increases in TC wind intensity ( ''medium confidence'' ). {11.7, 11.4, Box 11.1}

'''It is''' ''likely'' '''that the global proportion of Category 3–5 tropical cyclone instances''' [[#footnote-010|2]] '''has increased over the past four decades.''' The average location where TCs reach their peak wind intensity has ''very likely'' migrated poleward in the western North Pacific Ocean since the 1940s, and TC translation speed has ''likely'' slowed over the conterminous USA since 1900. Evidence of similar trends in other regions is not robust. The global frequency of TC rapid intensification events has ''likely'' increased over the past four decades. None of these changes can be explained by natural variability alone ( ''medium'' ''confidence'' ).

'''The proportion of intense TCs, average peak TC wind speeds, and peak wind speeds of the most intense TCs will increase on the global scale with increasing global warming''' ( ''high confidence'' ''').''' The total global frequency of TC formation will decrease or remain unchanged with increasing global warming ( ''medium confide'' ''nce'' ). {11.7.1}

'''There is''' ''low confidence'' '''in past changes of maximum wind speeds and other measures of dynamical intensity of extratropical cyclones. Future wind speed changes are expected to be small, although poleward shifts in the storm tracks could lead to substantial changes in extreme wind speeds in some regions''' ( ''medium confidence'' ''').''' There is ''low confidence'' in past trends in characteristics of severe convective storms, such as hail and severe winds, beyond an increase in precipitation rates. The frequency of spring severe convective storms is projected to increase in the USA, leading to a lengthening of the severe convective storm season ( ''medium confidence'' ); evidence in other regions is limited. {11.7.2, 11.7.3} .

<div id="Compound" class="h2-container"></div>

<span id="compound-events-including-dryhot-events-fire-weather-compound-flooding-and-concurrent-extremes"></span>