Since the term was first coined in 1999, it has been used sparingly to signal “atypical” danger. Each of these dates represents a high-impact, violent event where the standard warning wasn’t enough.
| Date | Location (Oklahoma) | Significance |
| May 3, 1999 | S OKC / Moore (Oklahoma) | The first-ever use of the term. An F5 tornado moved through Bridge Creek and Moore, prompting the NWS to manually add “Emergency” to convey the extreme risk. |
| May 8, 2003 | Moore / SE OKC | An F4 tornado followed a path hauntingly similar to the 1999 event, cementing the emergency alert’s role for the OKC metro. |
| May 9, 2003 | W and N OKC | A rare back-to-back emergency day, as another violent tornado struck northern suburbs like Edmond. |
| May 20, 2013 | S OKC / Moore | A catastrophic EF5. The emergency was triggered as radar confirmed a massive debris ball lofted thousands of feet into the air. |
| May 31, 2013 | El Reno | The widest tornado in recorded history (2.6 miles). The emergency highlighted the erratic and deadly nature of this specific storm. |
| May 6, 2015 | Bridge Creek | A rain-wrapped EF3/EF4-strength storm that caused significant damage in areas already scarred by previous major tornadoes. |
| May 9, 2016 | Roff / Hickory | Demonstrated that the NWS will use the alert for rural areas if the storm shows high-end EF3+ intensity and clear debris. |
| May 19, 2024 | Custer City | A violent long-track tornado in western Oklahoma that maintained “Emergency” status for a significant portion of its path. |
| April 23, 2026 | Enid | The most recent addition. A violent EF4 with 170 mph winds that maintained a 30-minute path of destruction through populated areas. |
What Makes Enid Technically Significant?
The Enid EF4 is notable because it hit the technical “trifecta” required for an Emergency designation:
- Confirmed Large/Violent Tornado: Ground observers and high-resolution radar confirmed a wedge-shaped tornado.
- Confirmed Catastrophic Damage: “Real-time” reports of destroyed structures in neighborhoods like Gray Ridge and near Vance Air Force Base.
- High-Population Threat: The storm’s path took it directly toward a city center (Enid), rather than remaining in open farmland.
The Wind Data: 170 mph vs. The 1999/2013 Monsters
While the Enid storm’s 170 mph winds were lower than the 200+ mph recorded in 1999 and 2013, it was technically identical in its destructive efficiency. At 170 mph, wood-frame houses are leveled, and large vehicles are lofted—a threshold that NWS meteorologists consider “survivable only in a below-ground shelter or reinforced safe room.”
The significance of the Enid EF4 on April 23, 2026, isn’t just in the damage it caused—it’s in how it technically measures up to the most violent storms in Oklahoma’s history.
When comparing the Enid 2026 storm to the Moore 2013 EF5, we see a narrow but critical gap in technical metrics that determines the difference between “Violent” (EF4) and “Catastrophic” (EF5).
Technical Wind Speed Comparison
While both storms triggered the rare Tornado Emergency alert, their peak estimated wind speeds tell the story of their intensity:
| Metric | Enid EF4 (April 23, 2026) | Moore EF5 (May 20, 2013) |
| Peak Wind Speeds | 170 mph | 200–210 mph |
| Alert Level | Tornado Emergency | Tornado Emergency |
| Duration | 30 minutes | 40 minutes |
| Damage Class | Violent (Top 2%) | Catastrophic (Top 0.1%) |
The Data Gap: Why 170 mph vs. 210 mph?
The Enhanced Fujita (EF) Scale isn’t just about how fast the wind blows; it’s about what those winds do to specific “Damage Indicators” (DIs).
- Enid’s 170 mph (EF4): This rating is typically based on DIs like well-anchored homes losing their roofs and most exterior walls, or large vehicles being thrown. At 170 mph, a storm is capable of leveling entire neighborhoods, as seen in Enid’s Gray Ridge area.
- Moore’s 210 mph (EF5): To reach this technical threshold, a storm must do more than level a house—it must sweep the foundation clean or “scour” the ground, removing several inches of topsoil. In 2013, the Moore tornado was upgraded to an EF5 specifically because of the total destruction of Briarwood Elementary, where even reinforced interior rooms were compromised.
The Role of Technology: Radar & Dropsondes
In both cases, NWS Norman utilized cutting-edge technology to confirm the severity in real-time.
- TDS (Tornado Debris Signature): For the Enid storm, radar confirmed debris lofted thousands of feet into the air, allowing forecasters to maintain the Tornado Emergency status throughout the storm’s 30-minute lifespan.
- Dropsonde Comparison: While dropsondes (sensors dropped into the storm) are more common in hurricanes, mobile research teams often deploy similar sensors near Moore and Enid. The data from 2013 showed a “vertical profile” of wind that was significantly more compact and intense than the broader, slightly less concentrated wind field observed in Enid.
The History of Tornado Emergencies in NWS Tulsa (Rest of Oklahoma)
NWS Tulsa has a very short list of these high-end alerts, and like Norman, their history is dominated by May events.
- May 21, 2019 (Tulsa/Bixby/Sapulpa): A long-track, violent tornado prompted an emergency as it moved through the Tulsa metro area during a historic flood and severe weather outbreak.
- May 22, 2011 (Joplin – Regional Impact): While Joplin is in Missouri (NWS Springfield), the NWS Tulsa office coordinated heavily on the warnings for the parent supercell as it crossed the state line.
By Enid triggering an emergency in April, it signals a shift for both major NWS offices in the state.