Issued on the 5th of each month is the ECMWF “monthlies” extending to 6 months. The projected upper air forecasts for June through September are indicated (Fig. 1-4). What we’re looking for are areas of semi-permanent high pressure which best identify areas where anomalous heat and dry climate persist leading to a potential drought. The obvious region exposed to this risk according to ECMWF is Central and Southwest Europe during August and September.

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.