EF1 Tornado — Delaware, Oklahoma

2025-06-17 to 2025-06-18 · near Topsy, Delaware, Oklahoma

Event narrative

This tornado developed within a squall line to the northwest of Eucha, and moved northeast for nearly 4 miles. The tornado was embedded in a precipitation core within the line. Many trees were uprooted or snapped along the path. Three power poles were damage when trees fell on the associated lines. A few homes received minor damage, mostly from falling trees, and a poultry house was overturned. Based on this damage, maximum estimated wind in the tornado was 90 to 100 mph.

Wider weather episode

Thunderstorms developed over north central and northwestern Oklahoma during the early evening of the 17th, near an outflow boundary from earlier thunderstorms, and north of a developing warm front that stretched across the area. The atmosphere ahead of the thunderstorms over eastern Oklahoma had become very unstable. The strong instability combined with strong wind fields and strong wind shear associated with an intense upper level disturbance moving through the region, resulted in a few supercells that evolved into a severe squall line that moved through the area during the mid to late evening of the 17th, and early morning of the 18th. Widespread damaging wind, multiple tornadoes, and large hail up to golf ball size occurred across northeastern Oklahoma as the storms moved through the area.

View location on OpenStreetMap → (36.4610, -94.9880)

Source: NOAA Storm Events Database, event_id 1279685. Narrative written by the NWS forecast office that issued the report.