Meteorologist Chris Tomer is pointing toward what could potentially be a significant shift in global weather patterns. A super El Niño may be developing, and its effects on the United States could be dramatic by this summer.
The United States is currently under an El Niño watch, with La Niña still lingering but fading fast. Forecasters expect a transition to neutral conditions by May, followed by a full El Niño by June and early summer. What makes this cycle unusual is the sheer magnitude of warming being projected in the South Pacific near the equator.
A standard El Niño is declared when sea surface temperatures in the Niño 3.4 region exceed plus 0.5 degrees Celsius above normal. A super El Niño pushes that threshold to plus 2 degrees Celsius. Tomer says that according to 13 different models totaling 637 ensemble members, the weighted median forecast is plus 2.2 degrees Celsius, well into super El Niño territory. This level of warming generally only occurs roughly once every 10 years.
The southern tier of states from California through Texas and into the Gulf South can expect warmer and wetter than normal conditions through June, July, and August. The northern jet stream is expected to remain displaced northward, funneling storm energy into the south.
For drought-stricken parts of the West, this could bring serious relief. Tomer points to the near-total absence of snowpack across much of the Rockies as a troubling baseline, but sees the potential for a robust North American monsoon across Colorado, New Mexico, Arizona, and Wyoming as a genuine positive outcome.
On the severe weather front, El Niño conditions historically reduce tornado and hail activity across the central United States. Since the country is still transitioning out of La Niña through spring, Tomer expects probabilities to fall somewhere between the two patterns, but leaning toward the calmer El Niño outcome.
