May 2019 featured the strongest negative phase of the North Atlantic Oscillation (NAO) in the month of May since 1950. A composite of the next strongest 9 years rolled over to June suggests warmer themes across the Mid-Continent, going against current model themes. pic.twitter.com/rHcoQaeb1n

— Maxar | WeatherDesk (@Maxar_Weather) June 7, 2019