OKLAHOMA CITY, Oklahoma — The window for dangerous severe weather is opening tonight across Oklahoma and southeast Kansas, and confidence is rising fast. Isolated supercells are expected to develop between 6 and 9 PM CDT across a corridor stretching from Lawton and Oklahoma City north through Tulsa and up toward Wichita — and these storms are capable of producing every severe weather hazard at once: very large hail, damaging straight-line winds, and EF2 or stronger tornadoes.
The pink-outlined zone on tonight’s simulation map covers one of the most populated corridors in the Southern Plains — and the Energy Helicity Index values running through this zone are in the range that supports significant, long-track tornado development.
Cities in Tonight’s All-Hazards Zone
- Oklahoma: Oklahoma City, Tulsa, Enid, Lawton, Ardmore, Wilburton — entire central Oklahoma corridor inside the primary threat box
- Kansas: Southeast Kansas including Fredonia, Chanute — northern extension of the supercell zone
- Texas: Graham, Childress, northern Texas Panhandle fringe — southern edge of the hatched significant tornado zone
- Arkansas: De Queen, Mena area — eastern fringe as storms potentially track overnight
Primary Threats
- EF2+ tornadoes — the hatched significant tornado zone covers the entire Oklahoma-southeast Kansas corridor; isolated supercells in this environment are capable of producing strong, long-track tornadoes
- Very large hail — all severe hazards expected with tonight’s supercells; hail threat carries over from today’s daytime storms with an even more favorable overnight shear profile
- Damaging straight-line winds — supercells tonight will also produce destructive wind gusts alongside the hail and tornado threat
- 6 to 9 PM firing window — this is the critical period; if storms develop during this timeframe, they immediately have access to a dangerous overnight environment with a strengthening low-level jet
Why This Matters for Oklahoma City and Tulsa
Tonight’s threat is different from a typical afternoon severe weather event — and that difference makes it more dangerous. Storms firing between 6 and 9 PM in this kind of atmospheric setup hit the ground running. By the time they develop, the low-level jet is already strengthening after sunset, adding rotational energy to storms that are already organized supercells. There is no gradual ramp-up period — storms can go from initiation to tornado-warned within minutes.
The Energy Helicity Index values shown on the simulation map — the color shading running from green through red inside the pink box — measure the atmosphere’s ability to produce rotating storms. Values in the range shown over Oklahoma City, Tulsa, and the corridor between them are consistent with environments that produce significant tornadoes. This is not a marginal setup dressed up to look threatening. The atmosphere is genuinely loaded tonight…