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This video is a recorded excerpt from a live webinar on April 16, 2019.
Last summer was a hot one — the fourth hottest on record, in fact. Moreover, the most populous areas of the country experienced a particularly warm season, with fewer cool periods than usual. Consequently, electricity demand was high across the country.
Based on current imagery, sea surface temperatures across the equatorial Pacific Ocean are in Moderate El Niño range (or about +0.75C hotter than normal). If we take a closer look, the majority of temperature anomalies seem to be taking place in the subsurface. In other words, the ocean is running warm, but especially near the water’s surface (50-150 meters below the surface, to be precise). Deeper waters are less affected. What does this suggest? Current El Niño conditions could intensify if this trend persists, with warm subsurface waters keeping overall ocean temperatures at an elevated level.
Climate pattern projections point to a continued El Niño trend, at least through the summer. Remember: El Niño patterns are generally associated with cooler, wetter summers across Eastern North America and warmer, drier ones along the West Coast. It’s also worth noting that this is our second consecutive El Niño year. Second-year El Niño events are characterized by hot and dry summer weather in the Pacific Northwest in particular, and in turn also by colder-than-usual weather in the upper Midwest.
Back in 2011, Texans experienced an extraordinarily hot summer due to drought conditions and a La Niña climate pattern. Droughts in California over the last few years have also contributed to warmer-than-average temperatures. When a region experiences a drought, temperatures tend to rise; this year, however, drought conditions across the U.S. appear to be under control. Most regions of the country (especially those in the east) have experienced exceptionally wet weather and high soil moisture in 2019, consistent with the El Niño patterns seen across the continent beginning in 2018. While these patterns do limit the possibility of droughts, they may also indicate a stormy year ahead, with greater-than-average rain and snowfall. This summer, meanwhile, may be cooler than average if current soil moisture levels remain elevated.
The CFS model maintains a moderate strength El Niño pattern through the summer. The West Coast and New England may run warm, but most of the East Coast, along with the midcontinent, will experience unusually high levels of precipitation and cooler temperatures.
This model is a composite of other international models. Like the CFS Model, it predicts an ongoing moderate El Niño pattern through the summer, with warmer-than-usual weather for the West Coast and Northeast.
Ocean temperatures in the Gulf of Mexico and across the Eastern Seaboard are running much warmer than usual. However, closer to the equator, temperatures are near normal for this time of year. Warm temperatures near the equator are associated with a greater risk for major hurricanes; current levels do not suggest the presence of such a risk. Additionally, the “wind shear” effect common to El Niño weather patterns (like the one we are seeing this year) tends to diminish the strength of hurricane systems before they make landfall.
The bottom line is that this summer will likely be slightly cooler than last summer. But keep in mind: just because this year could be cooler than last year does not mean it will be cool relative to, for example, the 30-year average. Demand will probably continue to run higher than any long-term average. However, there is relief in sight for much of the continental U.S., where we expect temperatures to remain relatively cool roughly between the Rocky Mountains and the Mississippi River.
It will be a different story in California, and even moreso for the Pacific Northwest where an ongoing El Niño pattern is expected to drive temperatures higher and keep the climate relatively dry. The East Coast (and New England in particular) could also run warmer than usual if current projections hold true.
All in all, it could still be a very, very warm summer. Matching last year’s summer heat, however, seems less likely. States closer to the middle of the country — Texas included — are expected to have a cooler summer, while temperatures near the coasts, and in the more northern states along the coasts specifically, will be warm.
Posted: May 10, 2019