At a Glance‍

• Salient Predictions uses AI to forecast weather 52 weeks ahead
• Many weather providers are forecasting an abnormally hot summer across nearly all of the continental U.S.
• Salient’s seasonal forecast is more nuanced and forecasts that the highest probabilities for above normal heat will be in the Great Plains and eastern Continental U.S.

Impact of Extreme High Temperatures

Will the summer of 2024 repeat the extreme heat of 2023, the year of record hot temperatures? In July 2023, Earth broke or tied its record for the hottest day on record, four days in a row. High temperatures have significant impacts, and are one of the leading causes of weather-related deaths in the U.S. Extreme heat adversely affects agriculture by hampering plant growth and causing heat stress in livestock. Heat waves can also worsen droughts and wildfires, further damaging agriculture and increasing insurance costs. Additionally, higher temperatures strain the U.S. energy system by boosting electricity demand for cooling while reducing the capacity of transmission lines, potentially causing reliability issues and higher energy prices.

Many weather sources forecast a scorching summer

Headlines from many weather sources are warning of another hot summer. The Weather Channel’s headlines say prepare for a scorching season: "Summer 2024 Temperature Outlook: It Could Be One Of The Nation's Hottest". Accuweather echoes the forecast, predicting “Sizzling Summer Temperatures Could Lead To Higher Power Bills Across America”. Dr. Todd Crawford, Vice President of Meteorology at Atmospheric G2 warns, “we can expect an abnormally hot summer this year” [reference]. The Climate Prediction Center's (CPC) Seasonal Temperature Outlook is equally concerning, projecting above-average temperatures for nearly all of the continental U.S., with the Mountain West to Texas facing a ~70% chance of above-normal heat.

‍Salient’s diverging seasonal and monthly forecast predicts the current heat wave will fade

Salient's highly reliable and accurate probabilistic weather forecasts, extending up to a year in advance, provide a counter view to others' heat predictions. The Salient quarterly outlook, issued concurrently with the CPC forecast, suggests near-normal seasonal temperatures for the western and some midwestern states around the Great Lakes, as shown in light tan in Figure 3. For the Great Plains and eastern Continental United States (CONUS) states, the Salient June-July-August (JJA) 2024 seasonal outlook indicates the highest probabilities for above-normal temperatures, represented in a brown gradient. Note that the Salient tercile (above-below-near normal) view uses a 40-year trend-adjusted climatology as its baseline for normal while the CPC uses a 30-year average (1991-2020) with no trend.

Despite potential above-normal average temperatures for specific regions, monthly averages can still fluctuate between above and below normal. An alternate forecast view highlights monthly temperature anomalies or deviations from a climatological average. Salient offers multiple climatological reference periods for calculating anomalies to meet the needs of specific sectors like energy and agriculture. Using a 10-year norm for comparison, Florida is predicted to experience anomalously warm temperatures throughout the summer, with a probability range of 70-80%. Conversely, the western coast is forecasted to have negative anomalies, while the northern plains transition from negative to positive anomalies. Texas is expected to start anomalously warm but likely shift to anomalously cooler temperatures in July and August compared to the 10-year historical average.

These monthly averages offer crucial directional insights, allowing ample lead time to devise contingency strategies. Monitoring weekly average forecasts provides additional signals, which are essential for making informed decisions based on specific temperature thresholds that necessitate action.

Assessing risk of exceeding thresholds

When assessing the risk of certain temperature thresholds being crossed at specific locations, it can be useful to focus on the forecast probability of exceeding critical temperature anomalies, especially when compared to the climatological likelihood. For instance, areas with a >33% risk of exceeding a 10℉ anomaly, compared to a 40-year trend-adjusted climatology, are highlighted below in Figure 5.

In Boise, the forecasted probability is 44%, significantly higher than the 7% probability based on climatology. This means there is a 6x climatological risk of seeing warm temperature anomalies above 10℉ even after accounting for the warming climate trend!

Similarly, considering temperatures in the 95th percentile, an area with a 5% probability based on a 40-year trend-adjusted climatology shows a 15% probability in the Salient forecast. Although 15% may seem minor, it represents a 3x increase in risk compared to the climatological likelihood, which can be substantial depending on potential losses and the cost of inaction.

Currently, there is consensus between the CPC forecast and Salient that parts of the Plains and the Eastern states will have above-normal-temperatures this summer. Weather is inherently uncertain, but Salient's data-driven approach firmly establishes the bounds of uncertainty, enabling decision-makers to utilize the probabilities of possible outcomes more effectively. By integrating Salient’s probabilistic forecasts, leaders gain increased accuracy and reliability for more confident and strategic decision-making.