An important step in the methodology presented in Charlton and Polvani (2007) was incorrectly reported.

The first sentence in the last paragraph in the right column on page 451 reads, “Once a warming is identified, no day within 20 days of the central date can be defined as an SSW.” This is incorrect and should read, “Once a warming is identified, an interval of 20 consecutive days with westerly winds must exist before the following central date can be defined.”

The authors are grateful to Felix Bunzel and Elisa Manzini of the Max Planck Institute for Meteorology for drawing this error to our attention.

REFERENCE

REFERENCE
Charlton
,
A. J.
, and
L. M.
Polvani
,
2007
:
A new look at stratospheric sudden warmings. Part I: Climatology and modeling benchmarks
.
J. Climate
,
20
,
449
469
.