Fig. 1: The global sea surface temperature anomaly analysis for July 2022 provided by the International Research Institute for Climate and Society and regional annotations.
Discussion: In July, the Pacific decadal oscillation (PDO) was -2.86 according to NOAA/NMFS Southwest Fisheries Science Center. The monthly value is a top-5 monthly strongest cool phase (since 1950). The intense -PDO signature is misleading. Usually, a strong -PDO is present due to cool SSTA off the North America West Coast while waters north of Hawaii are warm. In 2022, waters off the North America West Coast have warmed BUT compared to the titanic warm intensity of marine heat wave NEP22A north of Hawaii, the comparison of regional SSTA between the two zones is dramatic. This signature is historically unique. If NEP22A merge with the warming SSTA off the southwest U.S. Coast (a catalyst to this year’s wet monsoon in the Southwest U.S.), the East Pacific could warm to record levels and dissipate -PDO. This possibility is not expected (by Climate Impact Company) but close monitoring is required. The regional SSTA influence on global climate right now is astounding including unusually warm SSTA and associated very hot weather surrounding Europe and just-off the Asia East Coast. In the tropics, La Nina is regaining strength likely related to the onset of negative Indian Ocean Dipole. The tropical North Atlantic (TNA) index plummeted to -0.04 in July due to stronger than normal trade winds across the tropical North Atlantic. Although warming is forecast in this region, the current unexpectedly cooler SSTA in the North Atlantic main development region (MDR) for hurricanes caused by stronger trade winds is an inhibiting factor for hurricane development.