The meteorological summer (JUN/JUL/AUG) 2023 CDD is 887 ranking the 8th coolest of this century. Only Texas and the Upper Midwest have observed warmer than normal temperatures so far during summer 2023 while California and the Intermountain West are cool and the East near normal.

A warm mid-winter pattern across South America this year thanks to an amplified upper-level ridge centered just-off the North Coast of Chile and inspired by aggressive anomalous warmth of the northeast South Pacific Ocean off the South America Coast and vigorous El Nino warming of the eastern tropical Pacific.

The Nino34 SSTA warmed to +1.2C last week as oceanic El Nino strengthens to moderate intensity. The ENSO climate budged toward El Nino in July as supported by a 2-to-3-week period of a negative southern oscillation index (-SOI) although SOI has shifted into weak positive phase the past 2 days.

In 10-15 days, possible changes are looming. The global atmospheric angular momentum (GLAAM) pattern may flip negative for the first time during the summer season signaling a slowdown in the upper air pattern. If so, recent much warmer GFS 11-15-day forecasts and the ECM 16-20/16-30-day forecasts may regenerate another fierce hot upper ridge pattern for mid-to-late August.