Atlantic Multi-decadal oscillation (AMO) index from 'Coloradostatu' remained strongly negative in April - 5th lowest on record for April (since 1950), trailing only 1990, 1994, 2015 and 2016. Low AMO value primarily due to very cold SSTs in far North Atlantic.
http://twitter.com/philklotzbach/status/1125430576930902016
Recente studie: http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-18-0647.1
& enige uitleg
http://www.sciencedaily.com/releases/2019/04/190415143955.htm