A succession of three reversals of the meridional gradient of mean stratospheric temperature during January-February 1979 culminated in the reversal of the zonal mean arctic flow at the 10-mb level. Strong tropospheric-stratospheric interaction occurred in the form of coherent wave 1 and 2 height amplifications. The flow reversal, in late February, was due mainly to wave 2. In the first of the three temperature gradient reversals, there was an unusually strong development of the ''Aleutian'' anticyclone. The origins of this anticyclone are traced to the retrogression of height wave 1 in the troposphere and its superpositioning with wave 2 near the Greenwich meridian on 16 January, with continuing retrogression and strong amplification after this date along with the development of westward tilt with height and strong poleward heat transport.