Gulf heat dome and polar jet stream shape North America's solar outcomes in May

05 June 2024

A strong polar jet stream and a record-breaking heat dome in May resulted in a stark contrast in irradiance patterns across North America. The western and central USA, along with Mexico, experienced higher than normal irradiance, while the Gulf and East Coast regions faced lower irradiance.

GHI Deviation - North America May 2024.png

The persistent heat dome over the Gulf of Mexico has led to hot conditions across Mexico, with irradiance levels reaching nearly 130% of climatological averages. Most of Mexico and many Central American states are undergoing a record-breaking heat wave, exacerbated by clear skies due to a weak subtropical jet stream. This situation is aggravating existing conditions that followed from the dry winter Mexico has experienced. The heat dome is expected to persist into June, shifting its influence towards the southern USA.

In the southeastern USA, wind and stormy weather has led to irradiance levels being almost 20% below average. The East Coast has also seen a drop of around 10% in irradiance from long term May averages. Southerly winds from the tropics brought warm and moist air northward, contributing to the unusually warm conditions and lower than normal irradiance in Gulf states like Texas, Mississippi, Georgia, and Alabama. This is a preview of the anticipated stronger-than-normal hurricane season, which will not bode well for solar energy production due to risk of damage, increased cloudiness and temperature-induced losses. The moist, hot air has also resulted in severe storms, such as those that hit Texas earlier this week and adjacent states over the weekend. These storms put pressure on the grid, leading to numerous outages and leaving many without power in the above average temperatures

Monthly Average - North America May 2024.png

In contrast, the strong polar jet stream has created favorable conditions for asset and grid operators in the western USA. The jet stream over the North Pacific caused unseasonably cool temperatures in the Northwest, bringing chilly temperatures and higher than normal irradiance. Solar irradiance in this region is up by almost 20% compared to long-term averages. This cool weather, coupled with long daylight hours, has provided optimal conditions for solar energy generation before the anticipated hot and dry summer.

Prepare for weather conditions and wildfire events that impact your power generation. Ensure you have high-resolution, accurate solar irradiance data required for your asset operations. Create a Solcast API toolkit to evaluate our data or reach out to our team for a free guided trial.

Dr. Hugh Cutcher

Dr. Hugh Cutcher

Data Scientist • Author

Hugh is a Data Scientist at Solcast. He holds a Bachelor of Engineering (Hons. I) in Mechanical Engineering and a PhD in Combustion from University of Sydney. Hugh believes that renewable energy is critical to ensuring a cleaner and safer world going forward and is excited to play a part in helping fulfil that potential.