The Nino34 SSTA cooled to the El Nino threshold (+0.5C) last week while the entire Nino SSTA region averaged +0.5C, which is slightly warmer than much of April. Notably, the Nino12 SSTA off the northwest coast of South America warmed dramatically the past 2 weeks. Meanwhile, in the subsurface, the cooling necessary to cause an ENSO phase change from El Nino to La Nina continued. In April, the subsurface equatorial Pacific was cooler and firmly within the La Nina threshold.

NOAA issued their fire risk outlook last week. In review, the May 2024 risk highlights Southeast Arizona, parts of eastern New Mexico, and north-central Florida as susceptible to fire development and expansion due to dry soils. Note that all the Hawaiian Islands are in a similar risk throughout the next 4 months. Also note the lack of fire risk in California into mid-summer due to plentiful soil moisture largely created by runoff from snowmelt.

Negative Scandinavia index which represents a sharp trough over Northwest Eurasia dominates the first half of May pattern. The trough lingers into mid-May according to ECM sustaining cool weather across Western Russia and a wet scenario across Southwest Russia and eastward.

Extremely dry weather was observed the last week of April across South-central to Coastal Brazil. The 10-day outlook maintains the dryness with high temperatures consistently in the 32-35C range. The dry pattern widens during the period.