When Lightning Strikes a Tank Farm: Lessons from Tornado Alley

Few facilities concentrate risk quite like a crude oil refinery. Large volumes of flammable hydrocarbons, miles of pipe rack, tall stacks, and — in Tornado Alley — some of the most severe thunderstorm activity in North America. Two well-known incidents involving Oil & Gas facilities in Oklahoma offer examples of why lightning prevention, not just lightning protection, has to be part of any serious tank farm safety strategy.

Tank Farms are at Risk from Lightning Strikes

The Wynnewood Refinery sits in a region frequently battered by severe thunderstorms, and inclement weather has repeatedly disrupted its operations. In April 2007, news archives report that lightning struck Storage Tank No. 138 at the Wynnewood refinery, peeling back part of the tank shell and igniting the naphtha product, sending flames and smoke hundreds of feet into the air and engulfing a neighboring 80,000-barrel tank as well. Fire officials at the time described tank fires as notoriously difficult to fight: easy to contain, but capable of burning for a day or more once established.

More recently, a cluster of thunderstorms moved through an area north of Wynnewood near Tulsa, Oklahoma on August 17, 2026. Lightning hit the Glenpool tank farm operated by Explorer Pipeline igniting three natural gas storage tanks and resulting in spectacular explosions that sent the lids of the tanks flying high in the air. Fortunately, no injuries were reported.

Taken together, these lightning-related explosions and fires at the refinery illustrate a broader truth about petroleum infrastructure: it sits at the intersection of two hazards that rarely combine safely – a high strike-attraction profile and highly flammable inventory.

CASE STUDY: Tank Farm Lightning Protection – a Calcasieu Refining Case Study

Why Lightning and Storage Tanks Are Such a Dangerous Mix

A crude oil storage tank doesn’t need a direct hit to catch fire. On floating roof tanks, the rim seal — the narrow annular gap between the floating roof and the tank shell — accumulates hydrocarbon vapor and is the single most common point of lightning-induced ignition at any tank farm. This is true for both internal floating roof tanks (IFRTs) and standard floating roof tanks.

On fixed roof tanks, the risk concentrates around vents, seams, and fittings. Even a lightning strike that is “successfully” grounded by a conventional lightning rod can still produce an ignition-capable arc at these vulnerable points, because conventional systems are designed to control where lightning strikes — not to prevent the strike from happening in the first place.

A Different Approach: Preventing the Strike, Not Just Surviving It

This is where Lightning Eliminators & Consultants (LEC) takes a fundamentally different approach than traditional lightning rods and air terminals.

Dissipation Array® System (DAS®)

Rather than inviting a strike into the protected area and routing its energy to ground like traditional lightning rods, LEC’s Dissipation Array System (DAS) is engineered to prevent the strike from occurring within the protected area at all. As a storm approaches, the electric field between the storm cell and the ground intensifies, and upward streamers begin to form from tall, conductive structures — tanks, stacks, and steelwork among them.

DAS units use an array of many grounded ionizing points to continuously bleed off the local charge differential through a process called point discharge, keeping the electric field below the threshold needed for a streamer to form. No streamer, no connection with the descending leader, no strike.

LEC has developed configurations purpose-built for the exact structures found at a facility like Wynnewood:

• Conic Array — wraps around cone and dome roof tanks, the primary configuration for fixed roof crude and product storage.
• Rim Array — mounted directly on a floating roof, moving with it as liquid levels change to maintain continuous protection at the rim seal, the single highest-risk point on a floating roof tank.
• Stack Array — designed for flare stacks and process exhaust stacks, which naturally attract strikes due to their height.
• Hemisphere and Parapet Arrays — protect instrument poles, control buildings, and switch gear rooms, where a strike can just as easily take down critical SCADA and process-control systems as it can ignite a tank.

For a facility with Wynnewood’s mix of storage tanks, flare stacks, and process buildings, a comprehensive DAS deployment can be engineered to cover the entire site as a single integrated system, changing the local electrical environment so a strike simply doesn’t happen in the protected zone.

Retractable Grounding Assembly® (RGA®)

For floating roof tanks specifically, LEC’s Retractable Grounding Assembly (RGA) addresses a second, related vulnerability: maintaining a reliable, low-impedance electrical bond between the floating roof and the tank shell at every product level. Conventional shunts or cables coil loosely as the roof rises, creating high impedance that can allow a sustained arc,  and ignition, during a lightning event.

The RGA’s patented retractable design keeps the grounding cable at the shortest possible length regardless of roof position, driving impedance down dramatically compared to a conventional bypass conductor and preventing the arc from ever sustaining long enough to ignite vapor at the rim seal.

The RGA installs in about two hours, retrofits onto tanks already in service. Today, more than 18,000 RGA’s are in service protecting floating roof tanks at facilities around the world.

Lightning Strike Prevention is Critical, Not Just Protection

Wynnewood’s history is a reminder that petroleum storage and processing infrastructure faces compounding risks that conventional lightning rods were never designed to fully solve. A grounded strike is still a strike, and at a facility handling millions of gallons of flammable product, that distinction can be the difference between a routine storm and a multi-day fire.

Don’t Wait for the Next Storm to Find Your Weak Point

Wynnewood’s tanks weren’t the first to be struck by lightning, and they won’t be the last facility to be hit. If your refinery, terminal, or tank farm doesn’t have a lightning strike prevention plan in place, the next severe storm cell rolling through is a question of when, not if.

Get a free lightning risk assessment from LEC’s engineering team. We’ll map your site’s strike probability zones, identify your most vulnerable tanks and structures, and show you exactly where a DAS and RGA deployment would eliminate your exposure — before the storm season tests it for you.               

Request Your Free Lightning Risk Assessment →

Or call 303-447-2828 to talk to a lightning protection engineer today.