Fall 2026 through spring 2027 severe weather climate outlook

By WAYNE ADAMS

Climate scientist

As we move through fall 2026 and look ahead toward winter and spring 2027, severe weather will remain something to watch across Heavener and LeFlore County. Damaging winds, large hail and tornadoes are all possible during this period. While spring remains the traditional focus for severe weather in eastern Oklahoma, strong storm systems can also produce severe thunderstorms during the fall and winter months.

One of the major climate influences being watched is El Niño. El Niño can alter the jet stream and storm track across the United States. For eastern Oklahoma, this is important because the position of the storm track helps determine when Gulf moisture, strong winds aloft and approaching weather systems come together. El Niño does not automatically mean more tornadoes. Some El Niño years have had relatively limited tornado activity across the southern plains, while individual El Niño seasons have still produced significant severe-weather events.

This fall, I am testing a new experimental severe-weather research model called the WALT Leaf Model. I am taking readings from leaves at different locations across Le Flore County and will follow those readings through the coming months. The purpose is to determine whether changes and patterns found in leaves can provide useful information about longer-term severe-weather potential.

Initial testing has included Spiro, Panama, Shady Point, Poteau, Howe and Heavener. The model produces a measurement called the Kink Index. Panama recorded 72, while Spiro, Shady Point and Howe each recorded 71. Poteau recorded 59. Two samples from Heavener produced readings of 62 and 41.

The tornado portion of the experimental model produced a 50 percent model signal at Spiro, Panama, Shady Point, Poteau and Howe. The two Heavener samples produced 39 percent and 35 percent. These percentages are readings from the experimental model. They do not mean there is a 50 percent chance that a tornado will strike any particular town.

For that reason, the outlook from fall 2026 through spring 2027 is not simply about how many tornadoes might occur. A season can have relatively few tornadoes and still contain one or two significant severe-weather episodes. Damaging winds and hail may also affect considerably larger areas than an individual tornado.

Perhaps the most interesting result from the early testing is the wind signal. Every location tested has returned an estimated wind range of 60 to 75 mph. Because the same result has appeared across several different communities, damaging wind will be one of the main things I watch as testing continues from fall into winter and eventually spring.

I will also be watching for QLCS-type severe weather. A QLCS is an organized line of thunderstorms that can produce damaging straight-line winds across a large area. These storm lines can also develop embedded circulations capable of producing brief, fast-moving tornadoes. This makes both damaging winds and tornadoes important when strong lines of thunderstorms move through eastern Oklahoma.

For Heavener, the first two experimental tornado readings are lower than several readings collected elsewhere in the county. However, both Heavener samples continue to show the same 60-to-75-mph wind signal found at the other locations. Additional testing will help determine whether this difference continues or is simply normal variation between sampling locations.

Over the coming months, I will continue testing the new WALT model from fall 2026 through spring 2027. The readings will be recorded before the weather occurs and later compared with actual severe-weather events. I will also compare the experimental results with traditional climate information, including El Niño and established severe-weather climatology. This will allow us to see whether the new model identifies patterns that are useful over an entire severe-weather season.

For residents of Heavener and Le Flore County, the early message is to remain weather-aware throughout fall 2026, winter 2026–27 and spring 2027. Damaging winds currently stand out in the experimental research, but hail and tornadoes will also be monitored closely. As the seasons progress and more information becomes available, this outlook can be updated to show whether the climate and experimental signals are strengthening, weakening or changing.

The WALT Leaf Model is experimental research and is not a replacement for official forecasts, watches or warnings. During severe weather, residents should follow National Weather Service warnings and local emergency information.

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