Lightning lit up the sky above Cortez on an evening when a tornado was reported near Towaoc.Cortez Journal file photo
Lightning data is just a click away.
The National Weather Service in Grand Junction has recently upgraded its Lightning Potential Index, or LPI. In layman’s terms, it’s a program that allows the public to go online and check the risk of lightning in their area.
The operating system used by the weather service underwent an upgrade in March, but the LPI system needed a few tweaks for compatibility.
The program went live last week.
Paul Frisbie, a lead forecaster for the National Weather Service, created the program and made the recent improvements. The data providing people with lightning-risk information is updated every morning online, said Jim Pringle, forecaster with the National Weather Service in Grand Junction.
The online map shows four levels of lightning risk, Pringle said – low, moderate, high and extreme.
The tool can be used to help residents avoid danger when planning outdoor activities, Pringle said.
“We use this as a decision-making tool for the people who we support,” he said. “Do you want to take the risk when there is a certain expectation of lightning?”
In order to determine the risk by region, the program uses several parameters, such as moisture content and stability in the atmosphere, and then runs an equation and lines up the factors to produce a result, he said.
The risk of lightning predicted for Thursday was “extreme” as of noon in most of La Plata, San Juan and Archuleta counties. The risk remained extreme until after 9 p.m.
“This can be a highly useful product for people to check in the mornings before they head out and plan any outdoor activities,” Pringle said. “If they see a high or extreme risk, they might want to reconsider what they are doing or change the time in which they are doing it to avoid the peak time of thunderstorm development, or maybe just plan an indoor activity for that particular day.”
Visit http://1.usa.gov/1xZF9ga to view lighting risk in western Colorado and eastern Utah.
The San Juan National Forest offers these tips on lightning safety in the backcountry:
Plan trips to descend from high elevations to avoid afternoon thunderstorms above timberline. A good rule of thumb is to descend to treeline by noon.
When skies begin to look threatening, they already are. Anytime clouds develop vertically and cloud bases grow dark, a lightning hazard exists, even before you hear thunder or see lightning.
Lightning bolts can strike 10-15 miles out from a thunderstorm.
If you recognize a hazard is developing, seek cover in a building or vehicle, if possible. That means a substantial building (not picnic shelters, bus stops, dugouts, etc.) or inside a metal, covered vehicle (not open jeeps, golf carts). If inside a vehicle or building, don’t touch anything that could conduct electricity.
If you find yourself in a thunderstorm while in the backcountry there are some precautions you can take:
Retreat from highly exposed areas to minimize the chance of a direct hit, and don’t be the tallest object in the vicinity. Lightning often seeks higher objects because it’s a shorter gap for the electrical charge to bridge, so being near a single tall tree or group of tall trees in an opening is also dangerous. Move into a stand of smaller trees in a lower position on the landscape.
The majority of lightning strikes are not direct hits, but rather arc from another object or through the ground after a nearby strike. Minimizing your contact with the ground will minimize the likelihood of being hit by a ground arc. In a worst-case scenario, squat down with your head on your knees, feet and legs together, and balance on the balls of your feet.
In dangerous situations, it’s advisable for groups to separate, not huddle together. By spreading out, you reduce the odds of everyone being hit.
Avoid things that conduct electricity, like water channels or metal fencing. Lightning can follow streams or barbed wire fences for long distances, flow into the ground and spread out.
Lightning myths and facts
Fact: A typical lightning flash is about 300 million volts and about 30,000 amps (in comparison, household current is 120 volts and 15 amps). There is enough energy in a typical flash of lightning to light a 100-watt incandescent light bulb for about three months or the equivalent.
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Myth: Lightning never strikes the same place twice.
Fact: Lightning often strikes the same place repeatedly; especially tall, pointed, isolated objects like lone trees on high ridges. The Empire State Building is hit nearly 100 times a year.
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Myth: If it’s not raining or there aren’t clouds overhead, you’re safe from lightning.
Fact: Lightning bolts can strike 10-15 miles out from a thunderstorm. Many lightning casualties occur because people do not seek shelter soon enough. If you hear thunder, retreat from high exposed areas and seek shelter immediately.
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Myth: If caught outside in a thunderstorm, seek shelter under a tree to stay dry.
Fact: Being underneath a tree is the second-leading cause of lightning casualties.
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Myth: If trapped outside and lightning is about to strike, lie flat on the ground.
Fact: Lying flat increases your chance of being affected by dangerous ground current. If caught outside in a thunderstorm, keep moving toward safe shelter; or worst-case scenario, squat down as low as you can, balancing on the balls of your feet while hugging your knees to limit your contact with the ground. If in a group, spread out apart from each other.
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Myth: A lightning victim is electrified. If you touch them, you’ll be electrocuted.
Fact: The human body does not store electricity. It is perfectly safe to touch a lightning victim to offer first aid.
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Myth: Rubber tires on a car protect you from lightning by insulating you from the ground.
Fact: Most cars are safe from lightning, but it is the metal roof and metal sides that protect you, not the rubber tires. Therefore, to be safe, you must not be touching the metal roof or metal sides at the time of a strike.
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Myth: If you are in a building, you are safe from lightning.
Fact: A building is safe during a thunderstorm as long as you avoid anything that conducts electricity. This means staying off corded phones, electrical appliances, wires, TV cables, computers, plumbing, metal doors and windows. Windows are hazardous for two reasons: Wind can blow objects into the window, causing glass to shatter and, in older homes, lightning can come in cracks along the sides of windows.
Source: U.S. Forest Service
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