The Hawaiian Islands brace for a rare “Kona Storm” this week. An intense storm has become quasi-stationary west-northwest of the islands and caused surface wind across Hawaii to turn into the southwest. A southwest wind in Hawaii is rare and known as a leeward or “Kona” wind. Coupled with the unstable atmosphere associated with the upper trough, the moist southwest wind leads to frequent wind squalls, life-threatening flooding rainfall and even heavy snow in the highest mountains.

The wettest spring since 2010 has just completed across Australia. Spring was an all-time top 10 wet spring in Australia’s climate record. Developing La Nina will be blamed for the wet pattern and certainly contributed. In fact, according to multivariate ENSO index (MEI) the La Nina climate pattern emerging in 2020 never ended in 2021. However, other factors contributed (heavily) to the wet pattern across Australia during their just-ended meteorological spring season.

In recent days the Madden Julian oscillation has emerged across Indonesia. Due to the increased attendant heavy convection, the atmosphere has become increasingly supportive of tropical cyclone activity. In the West Pacific tropics Typhoon Nyatoh has developed. This system reaches category-2 tropical cyclone strength while turning north and northeast over the next couple days. MJO also spawned a tropical depression well northwest of Australia.

The adjusted climatology (including 2021) for North Atlantic tropical cyclones maintains the more active 30-year values compared to the longer-term 50-year values. The number of tropical cyclones each season nowadays averages close 15 whereas the 50-year climatology is somewhat lower at 12.6 and 11.9 for 1950-2021.