Since late January, the Pacific North America (PNA) index has shifted to a (mostly) steady negative phase. A brief positive phase is with us now, but strengthening negative phase returns in the latest 15-day forecast. The -PNA pattern occurs when an upper-level troughing in the jet stream pattern occurs just off the North America West Coast. The persistence of the -PNA pattern has caused the Northeast Pacific to cool, the Northeast Pacific marine heat wave (MHW) to shift westward and reinvigorate the cool phase of the Pacific decadal oscillation (-PDO).

The Europe Drought Observatory identifies strengthening drought across parts of Western Europe. Drought is also intensifying in Turkey. The latest week 2-4 outlook indicates some patchy beneficial rain but not enough to turn around dry soil conditions.

The daily southern oscillation index (SOI) is -1.2 which is exceptionally negative especially when compared to the dominant La Nina-like positive phase of the past one year. The shift to negative phase is due to the passage of the convection phase of the Madden Julian oscillation (MJO) through the equatorial East Pacific and onto the Atlantic basin. The MJO strength is exceptional and one of the strongest signatures in recent years.

A familiar upper air forecast over the next 15 days across South America with an amplified upper ridge across the warm SSTA east of Argentina and a low-pressure trough extending north from near the Amundsen Sea cool SSTA pool. A transient MJO inspires a wet pattern across Brazil funneling moisture southward around the backside of the South Atlantic subtropical high into west and central portions of Argentina but missing much of the drought zone.