Wednesday, June 28, 2006

Some NWRs may go out today

In a PNS issued by the NWS Memphis, the forecasters state that they are performing maintenance on the NOAA Weather Radio systems and, as a result, they may go out for some short periods. This will take place from 9 AM - 4 PM. Additionally, the weekly test of the NWRs will take place tomorrow at its regularly scheduled time, instead of today.

Friday, June 23, 2006

Day Five - Lightning Safety Awareness Week

"Medical Aspects of Lightning"

How Big A Problem Is This? Statistics

Lightning has been the second largest storm killer in the U.S. for the last 40 years, exceeded only by floods. A lightning strike can result in a cardiac arrest (heart stopping) at the time of the injury, although some victims may appear to have a delayed death a few days later if they are resuscitated but have suffered irreversible brain damage.

According to Storm Data, a National Weather Service publication, over the last 30 years the U.S. has averaged 66 reported lightning fatalities per year. Due to under reporting, the figures are more realistically at least 70 deaths per year. Only about 10% of people who are struck by lightning are killed, leaving 90% with various degrees of disability.

ODDS OF BECOMING A LIGHTNING VICTIM
U.S. 2000 Census population 280,000,000
Odds of being struck by lightning in a given year (reported deaths + injuries) 1/700,000
Odds of being struck by lightning in a given year (estimated total deaths + injuries) 1/400,000
Odds of being struck in your lifetime (Est. 80 years) 1/5000
Odds you will be affected by someone being struck (Ten people affected for every one struck) 1/500

Who Gets Injured

While about one third of all injuries occur during work, workers compensation companies are often reluctant to acknowledge the injury or pay related medical expenses. About another third of injuries occur during recreational or sports activities. The last third occurs in diverse situation, including injuries to those inside buildings.

How Do Lightning Injuries Affect People?

Lightning tends to be a nervous system injury and may affect the brain, autonomic nervous system and the peripheral nervous system. When the brain is affected, the person often has difficulty with short-term memory, coding new information and accessing old information, multitasking, distractibility, irritability and personality change.

"Patients have difficulty in all areas that require them to analyze more items of information than they can handle simultaneously. They present (appear) as slow because it takes longer for smaller than normal chunks of information to be processed. They present as distractible because they do not have the spare capacity to monitor irrelevant stimuli at the same time as they are attending to the relevant stimulus. They present as forgetful because while they are concentrating on point A, they do not have the processing space to think about point B simultaneously. They present as inattentive because when the amount of information that they are given exceeds their capacities, they cannot take it all in."

Early on, survivors may complain of intense headaches, ringing in the ears, dizziness, nausea, vomiting and other post-concussion types of symptoms. Survivors may also experience difficulty sleeping, sometimes sleeping excessively at first and then only two or three hours at a time. A few may develop seizure-like activity several weeks to months after the injury.

Personality Changes / Self-Isolation

Many lightning victims may suffer personality changes because of frontal lobe damage and become quite irritable and easy to anger. People who wake up after the injury often do not have the ability to express what is wrong with them, may not recognize much, become embarrassed when they cannot carry on a conversation, work at their previous job, or do the activities that they used to handle. As a result, many isolate themselves, withdrawing from church, friends, family and other activities. Friends, family and co-workers who see the same external person, may not understand why the survivor is so different. Friends soon stop coming by or asking them to participate in activities. Families who are not committed to each other break up.

Obviously, depression becomes a big problem for people who have changed so much and lost so much. Suicide is something almost all severely injured people have thought about at one time or another. Occasionally, those who do not have access to medical care or who do not understand what is happening may resort to alcohol and other drugs, particularly those who have previously used these options. Family and friends of the survivor must remain supportive even though it may require an adjustment in their relationship with the survivor. An injury such as this affects the entire family, not just to the person hit.

Fatigue

Survivors often complain of becoming exhausted after only a few hours of work. This may be because tasks they used to do automatically now require intense concentration. Many return to work but find that they cannot do all of the activities required at their job.

Medical Testing

There are two kinds of medical tests:

  • Anatomic tests take a simple picture (x-ray) or measurement (blood count)
  • Functional tests show how something is working (PET, neuropsychological testing)

Sometimes function can be ascribed to the anatomic tests but often it cannot. The mental changes of a lightning survivor are functional (how the brain works) changes, not anatomic. Anatomic tests such as a CT scan and MRI are usually normal. More functional scans such as PET and SPECT may show changes but are hard to obtain due to their relative infrequency in medical centers. To use an analogy: if an electric shock were sent through a computer, the outside case would probably look OK (similar to a photo or x-rays of the person), the computer boards on the inside would probably look OK and not be fused nor melted (CT, MRI for the person), but when you boot up the computer it would have difficulty accessing files, making calculations, printing, etc. This situation is similar in a person with brain injury who has short-term memory problems, difficulty accessing and coding information, difficulty organizing output, etc.

More useful is a functional test of how a person's brain is working: a neurocognitive or neuropsychological testing. These tests are administered by a neuropsychologist, not by a psychiatrist. The tests consist of a 6-8 hour battery of tests including memory, IQ and organizational ability. Survivors of lightning and electrical injury usually have a characteristic pattern of deficits.

Delayed Problems

Another common, often delayed, problem for some survivors is pain, also difficult to quantify and manage. The pain may not be from chronic intense headaches but may be in the back (perhaps from compression and disc injury from the intense muscle contractions which may throw a person several yards at the time of the injury), or in an extremity. Some may have nerve entrapment syndromes and a small number may eventually develop Sympathetically Mediated Pain Syndrome.

Sometimes the functional tests ordered are testing the wrong thing. An electromyogram (EMG) measures only the motor fibers, which are seldom affected by lightning injury. Smaller pain carrying nerve fibers are not tested by EMG so that a normal EMG means little when ordered for someone with pain. Likewise, the standard EEG primarily measure surface readings of the brain and misses seizure activity in several deeper regions.

Decreased libido and impotence are often reported.

Help Exists - Lightning Strike and Electric Shock Survivors, International, Support Group

An organization of tremendous help to survivors, families, physicians and other professionals is Lightning Strike and Electric Shock Survivors, International (LSESSI), a support group formed in 1989 by a lightning victim. LSESSI has printed materials, offers tremendous support, networks survivors with others in their area, and provides an annual meeting where survivors come together for support and lectures from professionals who work with lightning and electrical survivors and their families. LSESSI can be reached at 910-346-4708, info@lightning-strike.org, or see their Website at http://www.lightning-strike.org/, or at P.O. Box 1156, Jacksonville, NC 28541-1156.

Four Factors Necessary for Recovery

The four most important factors in overcoming disability from lightning injury (or from any illness or major injury for that matter) are:

  • Supportive family/friends network.
  • Becoming your own advocate and learning as much as you can about this disability.
  • A physician willing to listen, read, learn and work with the survivor and their family.
  • A sense of humor.

Prevention

Far more important than treating survivors is preventing lightning injury. All of the people who helped make possible National Lightning Safety Awareness Week hope it will help you and your family learn how to avoid injury. Prevention is the KEY.

This factsheet courtesy Dr. Mary Ann Cooper- Associate Professor, Departments of Emergency Medicine and Bioengineering University of Illinois at Chicago

Thursday, June 22, 2006

Day Four - Lightning Safety Awareness Week

What is a Safe Shelter?

A house or other substantial building offers the best protection from lightning. In assessing the safety provided by a particular structure, it is more important to consider what happens if the structure gets struck by lightning, rather than whether the structure will be hit by lightning. For a shelter to provide protection from lightning, it must contain a mechanism for conducting the electrical current from the point of contact to the ground. These mechanisms may be on the outside of the structure, may be contained within the walls of the structure, or may be a combination of the two. On the outside, lightning can travel along the outer shell of the building or may follow metal gutters and downspouts to the ground. Inside a structure, lightning can follow conductors such as the electrical wiring, plumbing, and telephone lines to the ground.

Avoid Unsafe Shelters!

Unless specifically designed to be lightning safe, small structures do little, if anything, to protect occupants from lightning. Many small open shelters on athletic fields, golf courses, parks, roadside picnic areas, schoolyards and elsewhere are designed to protect people from rain and sun, but not lightning. A shelter that does not contain plumbing or wiring throughout, or some other mechanism for grounding from the roof to ground is not safe. Small wooden, vinyl, or metal sheds offer little or no protection from lightning and should be avoided during thunderstorms.

How Lightning Enters a House or Building

There are three main ways lightning enters homes and buildings: (1) a direct strike, (2) through wires or pipes that extend outside the structure, and (3) through the ground. Regardless of the method of entrance, once in a structure, the lightning can travel through the electrical, phone, plumbing, and radio/television reception systems. Lightning can also travel through any metal wires or bars in concrete walls or flooring.

Stay Safe While Inside

Phone use is the leading cause of indoor lightning injuries in the United States. Lightning can travel long distances in both phone and electrical wires, particularly in rural areas. Stay away from windows and doors as these can provide the path for a direct strike to enter a home. Do not lie on the concrete floor of a garage as it likely contains a wire mesh. In general, basements are a safe place to go during thunderstorms. However, there are some things to keep in mind. Avoid contact with concrete walls which may contain metal reinforcing bars. Avoid washers and dryers since they not only have contacts with the plumbing and electrical systems, but also contain an electrical path to the outside through the dryer vent.

Remember Your Pets

You may want to consider the safety of your family pets during thunderstorms. Dog houses are not lightning-safe. Dogs that are chained to trees or chained to wire runners can easily fall victim to a lightning strike.

Protect Your Personal Property

Lightning also causes significant damage to personal property each year. In addition to direct strikes, lightning generates electrical surges that can damage electronic equipment some distance from the actual strike. Typical surge protectors will NOT protect equipment from a lightning strike. To the extent possible, unplug any appliances or electronic equipment from all conductors well before a thunderstorm threatens. This includes not only the electrical system, but also the reception system. If you plan to be away from your home when thunderstorms are possible, be sure to unplug unneeded equipment before you leave.

Summary of Lightning Safety Tips for Inside the Home

  1. Avoid contact with corded phones
  2. Avoid contact with electrical equipment or cords. If you plan to unplug any electronic equipment, do so well before the storm arrives.
  3. Avoid contact with plumbing. Do not wash your hands, do not take a shower, do not wash dishes, and do not do laundry.
  4. Stay away from windows and doors, and stay off porches.
  5. Do not lie on concrete floors and do not lean against concrete walls.

Wednesday, June 21, 2006

Day Three - Lightning Safety Awareness Week

"Lightning Safety Outdoors"

This document has two main sections: lightning safety when a safe location is nearby and risk reduction--not safety!--when a safe location is NOT close. No place is absolutely safe from lightning; however, some places are much safer than others. The SAFEST location during lightning activity is a large enclosed building, not a picnic shelter or shed. The second safest location is an enclosed metal vehicle, car, truck, van, etc., but NOT a convertible, bike or other topless or soft top vehicle.

Safe Buildings

A safe building is one that is fully enclosed with a roof, walls and floor, such as a home, school, office building or a shopping center. Even inside, you should take precautions. Picnic shelters, dugouts, sheds and other partially open or small structures are NOT safe.

Enclosed buildings are safe because of wiring and plumbing. If lightning strikes these types of buildings, or an outside telephone pole, the electrical current from the flash will typically travel through the wiring or the plumbing into the ground. This is why you should stay away from showers, sinks, hot tubs, etc., and electronic equipment such as TVs, radios, and computers.

Lightning can damage or destroy electronics so it's important to have a proper lightning protection system connected to your electronic equipment. The American Meteorological Society has tips for protecting your electronics from lightning.

Unsafe Buildings

Examples of buildings which are unsafe include car ports, covered but open garages, covered patio, picnic shelters, beach shacks/pavilions, golf shelters, camping tents, large outdoor tents, baseball dugouts and other small buildings such as sheds and greeenhouses that do not have electricity or plumbing.

Safe Vehicle

A safe vehicle is a hard-topped car, SUV, minivan, bus, tractor, etc. (soft-topped convertibles are not safe) . If you seek shelter in your vehicle, make sure all doors are closed and windows rolled up. Do not touch any metal surfaces.

If you're driving when a thunderstorm starts, pull off the roadway. A lightning flash hitting the vehicle could startle you and cause temporary blindness, especially at night.

Do not use electronic devices such as HAM radios or cell phones during a thunderstorm. Lightning striking the vehicle, especially the antennas, could cause serious injury if you are talking on the radio or holding the microphone at the time of the flash. Emergency officials such as police officers, firefighters, security officers, etc., should use extreme caution using radio equipment when lightning is in the area.

Your vehicle and its electronics may be damaged if hit by lightning. Vehicles struck by lightning are known to have flat tires the next day. This occurs because the lightning punctures tiny holes in the tires. Vehicles have caught fire after being struck by lightning; however, there is no modern day documented cases of vehicles "exploding" due to a lightning flash.

Bolts from the Blue

There are times when a lightning flash can travel horizontally many miles away from the thunderstorm cloud itself and then strike the ground. These types of lightning flashes are called "Bolts from the Blue" because they seem to come out of a clear blue sky. Although these flashes are rare, they have been known to cause fatalities.


When a Safe Location is Nearby:

  • Seek safe shelter when you first hear thunder, see dark threatening clouds developing overhead or lightning. Count the seconds between the time you see lightning and hear the thunder. You should already be in a safe location if that time is less than 30 seconds.
  • Stay inside until 30 minutes after you last hear thunder.

man running to safe location

Figure: When you hear thunder, run to the nearest large building or a fully enclosed vehicle. You are not safe anywhere outside.

Click here to calculate how far lightning is away from you

Plan Ahead! Your best source of up-to-date weather information is a NOAA Weather Radio (NWR). Portable weather radios are handy for outdoor activities. If you don't have NWR, stay up to date via internet, TV, local radio or cell phone. If you are in a group, make sure all leaders or members of the group have a lightning safety plan and are ready to use it.

Determine how far you are from a safe enclosed building or a safe vehicle. As soon as you hear thunder, see lightning or see dark threatening clouds, get to a safe location. Then wait 30 minutes after the last rumble of thunder before you leave the safe location. If you are part of a group, particularly a large one, you will need more time to get all group members to safety. NWS recommends having professional lightning detection equipment so your group can be alerted from significant distances from the event site.

When groups are involved, the time needed to get to safety increases. So you need to start leaving sooner. Your entire group should already be in a safe location when the approaching storm reaches within 5 miles from your location.

Here some two common scenarios with suggestions on how to safely respond.

Coach of Outdoor Sports Team

You are a manager of a little league team and have a game this evening at the local recreational park. The weather forecast for the day calls for a partly cloudy skies, with a chance of thunderstorms by early evening. You arrive in your vehicle while the kids arrive with their parents. Once arriving at the park, you notice the only buildings are the the restrooms, an enclosed building. Shortly after sunset, the skies start to cloud up and you see bright flashes in the sky to the west. The local radio station mentions storms are on the way.

In this case, the safest locations are the vehicles the kids came in or the rest rooms. You should have a choice of allowing the kids to go back to their vehicles or bring everyone into the restrooms. It is important NOT to stay in the dugouts as they are not safe place during lightning activity. Once at a safe place, wait 30 minutes after the last rumble of thunder before going back outside.

Family at the Beach

You plan to go to the beach or lake later this morning with the kids. The weather forecast calls for a nice morning followed by a 30 percent chance of afternoon thunderstorms. You decide to head for the beach in your minivan. The beach is about 5 minutes from the parking lot. The only nearby buildings are picnic shelters. By early afternoon you notice the skies darkening and hear distant thunder. What would be your lightning safety plan of action?

In this case, the best place to go is your car. Do NOT seek shelter under the beach picnic shacks because these are not safe in lightning storms. Wait 30 minutes until after the last thunder crack before going back to the beach or driving home.

Camping

You and your family are camping. As you and your spouse are preparing dinner on the camp stove, you here rumbles of thunder in the distance. You look around and you see your tent is nearby, and a large picnic shelter is just down the trail. Your car is about ¼ of a mile away parked at the trailhead. What should you and your family do?

In this case, the smartest thing to do is to round up your family and get into your car. The tent is not a safe place to be as it offers NO protection from a lighting flash. The picnic shelter is also not a safe location. (Both the tent and picnic shelter will keep you dry…but they offer NO protection from a lightning flash). It is best to remain in your vehicle for about 30 minutes after the last rumble of thunder is heard.


When a Safe Location Is Not Nearby

The lightning safety community reminds you that there is NO safe place to be outside in a thunderstorm. If you absolutely can't get to safety, this section is designed to help you lessen the threat of being struck by lightning while outside. Don't kid yourself--you are NOT safe outside.

Being stranded outdoors when lightning is striking nearby is a harrowing experience. Your first and only truly safe choice is to get to a safe building or vehicle. If you are camping, climbing, on a motorcycle or bicycle, boating, scuba diving, or enjoying other outdoor activities and cannot get to a safe vehicle or shelter, follow these last resort tips. These will not prevent you from being hit, just slightly lesson the odds.

  • Do NOT seek shelter under tall isolated trees. The tree may help you stay dry but will significantly increase your risk of being struck by lightning. Rain will not kill you, but the lightning can!
  • Do NOT seek shelter under partially enclosed buildings
  • Stay away from tall, isolated objects. Lightning typically strikes the tallest object. That may be you in an open field or clearing.
  • Know the weather patterns of the area. For example, in mountainous areas, thunderstorms typically develop in the early afternoon, so plan to hike early in the day and be down the mountain by noon.
  • Know the weather forecast. If there is a high chance of thunderstorms, curtail your outdoor activities.
  • Do not place your campsite in an open field on the top of a hill or on a ridge top. Keep your site away from tall isolated trees or other tall objects. If you are in a forest, stay near a lower stand of trees. If you are camping in an open area, set up camp in a valley, ravine, or other low area. A tent offers NO protection from lighting.
  • Wet ropes can make excellent conductors. This is BAD news when it comes to lightning activity. If you are mountain climbing and see lightning, and can do so safely, remove unnecessary ropes extended or attached to you. If a rope is extended across a mountain face and lightning makes contact with it, the electrical current will likely travel along the rope, especially if it is wet.
  • Stay away from metal objects, such as fences, poles and backpacks. Metal is an excellent conductor. The current from a lightning flash will easily travel for long distances (See Figure 1)

cows killed by lightning near metal fence

Figure: Dead cows lined up along a metallic fence. Lightning struck the fence, and the current traveled along the fence killing the cows. Photo Courtesy Ruth Lyon-Bateman

If lightning is in the immediate area, and there is no safe location nearby, stay a little aparts from other members of your group so the lightning won't travel between you if hit. Keep your feet together and sit on the ground out in the open. If you can possible run to a vehicle or building, DO so. It is much safer than sitting on the ground.

Motorcyclist/Bicyclist: So has anyone been hit riding a bike? Here are just a few real examples from the last few years.

  • Virginia Beach, VA: Motorcyclist killed while traveling on Route 58.
  • Altoona, PA: One motorcycle rider killed and three riders injured when they took shelter in a woods from a thunderstorm.
  • Wyoming: Motorcyclist injured while driving home on I-90 from Sturgis.
  • Taylor Park, CO: Dirt biker injured while heading down mountain pass.

Protect Yourself when on a bicycle, motorcycle or dirt bike.

  • Carry a portable Weather Radio or listen to commercial radio.
  • If you see threatening skies in the distance and you are passing a safe location, pull over and wait 30 minutes after the last thunder crack.
  • If you can turn around and get away from the storm, do so!
  • DO NOT ride into a lighting storm!

If you absolutely cannot get to a safe building or vehicle, here are some last resort choices:

  • Wait out the storm below an overpass. DO NOT touch steel girders. Move away from your bike. Remain on dry surfaces if possible. Overpasses are engineered structures and are likely to be properly grounded. Although an overpass is likely to be higher than the surrounding landscape, if it is struck by lightning, the electrical current will likely be channeled safely into the ground.
  • Look for a bridge. Stay away from water. Stay away from any metal surfaces. Be alert for rapidly rising water if under a bridge.
  • High tension wires: If high voltage electrical tension wires cross the road, you may want to seek shelter directly underneath these wires. Do not get too close to the large metal towers which hold up these wires. Stay at least 50 feet away. Electric companies design these high tension wires for lightning strikes. If lighting should strike the wires or towers, the current is designed to safely go deep into the ground.
  • If you are caught in the open and lightning is occurring within 5 miles, STOP riding, get off of your motorcycle/bicycle, find a ditch or other low spot and sit down.
  • Motorcyclists should move at least 50 feet away from their bike. Bicyclist should lay their bikes on the ground.

IMPORTANT: These recommendations are a last resort. You are NOT safe in these places just marginally safer than in the open.

Click here to read a story about a motorcyclist killed while riding in lightning.

On the Water

The vast majority of lightning injuries and deaths on boats occur on small boats with NO cabin. It is crucial to listen to the weather on a small aquatic vessel without a cabin. If thunderstorms are forecast, don't go out. If you are out on the water and skies are threatening, get back to land and find a safe building or vehicle.

Boats with cabins offer a safer but not perfect environment. Safety is increased further if the boat has a properly installed lightning protection system. If you are inside the cabin, stay away from metal and all electrical components. STAY OFF THE RADIO UNLESS IT IS AN ABSOLUTE EMERGENCY!

What should you do if you are on a small vessel and lightning becomes a threat? If the vessel has an anchor, then you should properly anchor the boat then get as low as possible.

Large boats with cabins, especially those with lightning protection systems properly installed or metal marine vessels are relatively safe. Remember to stay inside the cabin and away from any metal surfaces.

Scuba Divers

If the boat you are in does not have a safe cabin to be in during lightning activity, then you are safer diving deep into the water for the duration of the storm or as long as possible. Your first choice is to head in and get in safe building or vehicle.

Tuesday, June 20, 2006

Day Two - Lightning Safety Awareness Week

"Why do some clouds produce lightning and not others?"

How Powerful is Lightning?

Each spark of lightning can reach over five miles in length, soar to temperatures of approximately 50,000 degrees Fahrenheit, and contain 100 million electrical volts.

Lightning Is A Random, Chaotic And Dangerous Fact Of Nature

At any given moment, there are 1,800 thunderstorms in progress somewhere on the earth. This amounts to 16 million storms each year! Scientists that study lightning have a better understanding today of the process that produces lightning, but there is still more to learn about the role of solar flares on the upper atmosphere, the earth's electromagnetic field, and ice in storms. We know the cloud conditions needed to produce lightning, but cannot forecast the location or time of the next stroke of lightning. There are lightning detection systems in the United States and they monitor an average of 25 million flashes of lightning from the cloud to ground every year!

Lightning has been seen in volcanic eruptions, extremely intense forest fires, surface nuclear detonations, heavy snowstorms, and in large hurricanes, however, it is most often seen in thunderstorms. A thunderstorm forms in air that has three components: moisture, instability and something such as a cold front to cause the air to rise. Continued rising motions within the storm may build the cloud to a height of 35,000 to 60,000 feet (6 to 10 miles) above sea level. Temperatures higher in the atmosphere are colder; ice forms in the higher parts of the cloud.

Ice In The Cloud Is Critical To The Lightning Process

Ice in a cloud seems to be a key element in the development of lightning. Storms that fail to produce quantities of ice may also fail to produce lightning. In a storm, the ice particles vary in size from small ice crystals to larger hailstones, but in the rising and sinking motions within the storm there are a lot of collisions between the particles. This causes a separation of electrical charges. Positively charged ice crystals rise to the top of the thunderstorm, and negatively charged ice particles and hailstones drop to the middle and lower parts of the storm. Enormous charge differences (electrical differential) develops.

How Lightning Develops Between The Cloud And The Ground

A moving thunderstorm gathers another pool of positively charged particles along the ground that travel with the storm. As the differences in charges continue to increase, positively charged particles rise up taller objects such as trees, houses, and telephone poles. Have you ever been under a storm and had your hair stand up? Yes, the particles also can move up you! This is one of nature's warning signs that says you are in the wrong place, and you may be a lightning target!

The negatively charged area in the storm will send out a charge toward the ground called a stepped leader. It is invisible to the human eye, and moves in steps in less than a second toward the ground. When it gets close to the ground, it is attracted by all these positively charged objects, and a channel develops. You see the electrical transfer in this channel as lightning. There may be several return strokes of electricity within the established channel that you will see as flickering lightning.

Thunder

The lightning channel heats rapidly to 50,000 degrees. The rapid expansion of heated air causes the thunder. Since light travels faster than sound in the atmosphere, the sound will be heard after the lightning. If you see lightning and hear thunder at the same time, that lightning is in your neighborhood!

Negative Lightning And Positive Lightning

Not all lightning forms in the negatively charged area low in the thunderstorm cloud. Some lightning originates in the cirrus anvil at the top of the thunderstorm. This area carries a large positive charge. Lightning from this area is called positive lightning. This type is particularly dangerous for several reasons. It frequently strikes away from the rain core, either ahead or behind the thunderstorm. It can strike as far as 5 or 10 miles from the storm, in areas that most people do not consider to be a lightning risk area. The other problem with positive lightning is it typically has a longer duration, so fires are more easily ignited. Positive lightning usually carries a high peak electrical current, which increases the lightning risk to an individual.

For more on the science of lightning, see the NOAA National Severe Storms Laboratory.

Monday, June 19, 2006

Day One - Lightning Safety Awareness Week

Today is the first day of Lightning Safety Awareness Week. There is a video available for Day One, located here. You need RealPlayer to view it. Here is the first factsheet from the NWS (unedited).

Lightning—The Underrated Killer

In the United States, there are an estimated 25 million cloud-to-ground lightning flashes each year. Lightning can be fascinating to watch, but it is also extremely dangerous. During the past 30 years, lightning killed an average of 67 people per year in the United States based on documented cases. This is more than the average of 65 deaths per year caused by tornadoes and the average of 16 deaths per year caused by hurricanes. However, because lightning usually claims only one or two victims at a time, and because lightning does not cause the mass destruction left in the wake of tornadoes or hurricanes, lightning generally receives much less attention than the more destructive weather-related killers. While documented lightning injuries in the United States average about 300 per year, undocumented injuries caused by lightning are likely much higher.

Lightning Safety Awareness: Education is Key

Few people really understand the dangers of lightning. Many people don't act promptly to protect their lives, property and the lives of others because they don't understand all the dangers associated with thunderstorms and lightning. The first step in solving this problem is to educate people so that they become aware of the behavior that puts them at risk of being struck by lightning, and to let them know what they can do to reduce that risk. Coaches and other adults who make decisions affecting the safety of children must understand the dangers of lightning.

Watch for Developing Thunderstorms

Thunderstorms are most likely to develop on warm summer days and go through various stages of growth, development and dissipation. On a sunny day, as the sun heats the air, pockets of warmer air start to rise in the atmosphere. When this air reaches a certain level in the atmosphere, cumulus clouds start to form. Continued heating can cause these clouds to grow vertically upward in the atmosphere into "towering cumulus" clouds. These towering cumulus may be one of the first indications of a developing thunderstorm.

The Lightning Discharge: Don't Be a Part of It

During a thunderstorm, each flash of cloud-to-ground lightning is a potential killer. The determining factor on whether a particular flash could be deadly depends on whether a person is in the path of the lightning discharge. In addition to the visible flash that travels through the air, the current associated with the lightning discharge travels along the ground. Although some victims are struck directly by the main lightning stroke, many victims are struck as the current moves in and along the ground. While virtually all people take some protective actions during the most dangerous part of thunderstorms, many leave themselves vulnerable to being struck by lightning as thunderstorms approach, depart, or are nearby.

An Approaching Thunderstorm: When to Seek Safe Shelter

Lightning can strike as far as 10 miles away from the rain area in a thunderstorm. That's about the distance you can hear thunder. When a storm is 10 miles away, it may even be difficult to tell a storm is coming.

IF YOU CAN HEAR THUNDER, YOU ARE WITHIN STRIKING DISTANCE. SEEK SAFE SHELTER IMMEDIATELY!

The first stroke of lightning is just as deadly as the last. If the sky looks threatening, take shelter before hearing thunder.

The 30-30 Rule

Use the 30-30 rule where visibility is good and there is nothing obstructing your view of the thunderstorm. When you see lightning, count the time until you hear thunder. If that time is 30 seconds or less, the thunderstorm is within 6 miles of you and is dangerous. Seek shelter immediately. The threat of lightning continues for much longer period than most people realize. Wait at least 30 minutes after the last clap of thunder before leaving shelter. Don't be fooled by sunshine or blue sky!

If it is cloudy or objects are obscuring your vision, get inside immediately. It is always safer to take precautions than to wait.

Outdoor Activities: Minimize the Risk of Being Struck

Most lightning deaths and injuries in the United States occur during the summer months when the combination of lightning and outdoor summertime activities reaches a peak. During the summer, people take advantage of the warm weather to enjoy a multitude of outdoor recreational activities. Unfortunately, those outdoor recreational activities can put them at greater risk of being struck by lightning. People involved in activities such as boating, swimming, fishing, bicycling, golfing, jogging, walking, hiking, camping, or working out of doors all need to take the appropriate actions in a timely manner when thunderstorms approach. Where organized sports activities take place, coaches, umpires, referees, or camp counselors must protect the safety of the participants by stopping the activities sooner, so that the participants and spectators can get to a safe place before the lightning threat becomes significant. To reduce the threat of death or injury, those in charge of organized outdoor activities should develop and follow a plan to keep participants and spectators safe from lightning.

Indoor Activities: Things to Avoid

Inside homes, people must also avoid activities which put their lives at risk from a possible lightning strike. As with the outdoor activities, these activities should be avoided before, during, and after storms. In particular, people should stay away from windows and doors and avoid contact with anything that conducts electricity. People may also want to take certain actions well before the storm to protect property within their homes, such as electronic equipment.

Helping a Lightning Strike Victim

If a person is struck by lightning, medical care may be needed immediately to save the person's life. Cardiac arrest and irregularities, burns, and nerve damage are common in cases where people are struck by lightning. However, with proper treatment, including CPR if necessary, most victims survive a lightning strike, although the long-term effects on their lives and the lives of family members can be devastating.

Summary

Lightning is a dangerous threat to people in the United States, particularly those outside in the summer. With common sense, we can greatly reduce the number of lightning deaths. When thunderstorms threaten, get to a safe place, stay there longer than you think you need to, stay away from windows and doors and avoid contact with anything that conducts electricity.

Sunday, June 18, 2006

Tornado touchdown near Lakeland, TN yesterday

A brief F1 tornado touched down yesterday in the Franklin Farm subdivision near Lakeland, TN. According to a Public Information Statement from the NWS in Memphis, the tornado "touched down near Wood Sage Cove ... around 6:35 PM CDT." It then continued across Tall Hickory Drive and lifted back into the air. The path length was 500 yards. Here is one picture (thanks Google Earth) showing the upclose path of this tornado (click for larger version).

In addition to this map, I have also made an image of the track in relation to the Wolfchase Galleria area, for those not familiar with this area (click for larger version; look for white line with red dots).

According to the Local Storm Report, about 20 homes were damaged, and luckily, there were no injuries. However, a few homes had significant roof damage and one SUV had windows blown out of it.

The initial reports of this tornado came from local broadcast media. WPTY has a more detailed story on some damage. Look for more stories on this tornado from the local media in the days to come.

This week is Lightning Safety Awareness Week

Yes, the title says it all. June 18-24, 2006 is the official Lightning Safety Awareness Week from the National Weather Service. Each day this week, we will show you some different aspects of lightning safety, ranging from "The Medical Aspects of Lightning" to "Lightning Safety Outdoors". We will bring you the unedited article from the NWS.

If you want to get a head start on this week, go to http://www.lightningsafety.noaa.gov for all kinds of information on lightning.

Slight risk of severe weather today

According to the SPC, most of the Mid-South is under a slight risk for severe weather today. "Locally damaging winds should be the main threat with these storms." Our local NWS office says that the most likely time for this severe weather will be 10 AM-10 PM. They also say that the heavy rain produced by these storms may result in some flash flooding. Then, they end with this note - "Spotter activation may become necessary today into this evening."

I'll do a technical analysis of this situation this afternoon. Stay tuned for more information.

Saturday, June 17, 2006

Weather station back online

UPDATE: Well, the station has gone offline again. Will look at it again tomorrow when it is daylight and not raining.

ORIGINAL POST (2:53 PM CDT): Yea! Finally, after a month of downtime, my weather station is back online. You can view the data at Weather Underground, CWOP, or AWEKAS. The links to these websites are on the sidebar at the right.

Monday, June 12, 2006

TS Alberto Links

As Alberto bears down on the Florida panhandle, I figured I'd create a link directory of related links. I do not warrant any of the info contained on these pages nor do I warrant it. If any of these links have objectionable content on them, please post a comment and I will remove it.

National Hurricane Center Info
Homepage
Latest Public Advisory
3 Day Forecast Map

Weather Underground
Tropical Homepage
Tracking Map
Computer Models
Alberto Radar

Tampa Television
WTVT - 13 (FOX)
WFLA - 8 (NBC) [WeatherPlus Live Stream]
WTSP - 10 (CBS) [Live Radar Stream]
WFTS - 28 (ABC)

Tallahassee Television
WCTV - 6 (CBS)
WTWC - 40 (NBC)
WTXL (under construction)

Orlando Television
WESH - 2 (NBC) [WeatherPlus Live Stream]
WKMG - 6 (CBS)
WFTV - 9 (ABC)
WOFL - 35 (FOX)

Florida Government Information
Florida EMA
Shelter Info

If you have any links to add, please post a comment and I will add it!

Sunday, June 11, 2006

Some scattered severe weather this evening

Currently, there is a Severe T'storm Warning in effect for Mississippi County until 9:30 PM. Also, there is a T'storm Warning in effect for Carroll Co. until 9:30 PM. The Storm Prediction Center says that this severe activity could continue throughout the evening in its Mesoscale Discussion. In it, they say that we have a "continuing marginal severe wind threat, in addition to isolated large hail."

Saturday, June 10, 2006

Today is an Ozone Action Day

The air quality experts here in Memphis have placed the metro area under an Ozone Action Day (also known as a Code Orange). Here is a quote from the AIRNow website on what to do during an Ozone Action Day:
Action days are usually called when the AQI [air quality index] gets into the unhealthy ranges. Different air pollution control agencies call them at different levels. In some places, action days are called when the AQI is forecast to be Unhealthy for Sensitive Groups, or Code Orange. In this case, the groups that are sensitive to the pollutant should reduce exposure by reducing prolonged or heavy exertion outdoors. For ozone this includes: children and adults who are active outdoors, and people with lung disease, such as asthma. For particle pollution this includes: people with heart or lung disease, older adults and children. Occasionally, an action day is declared when the AQI is Moderate, or Code Yellow, if the levels are expected to approach Code Orange levels.
Click here to view the current health quality for Memphis from AIRNow.

Tropical Depression One forms


Well, here we go again. The first organized tropical system of the 2006 Atlantic Hurricane Season has formed. Tropical Depression One, at 8 AM CDT, was located 50 miles SSW of Cabo San Antonio, Cuba. It is moving toward the NNW at 12 mph. Maximum sustained winds are 35 mph, and some strengthing is expected. Heavy rainfall is expected with this system.

This system should not affect the Mid-South area.

-------------------
TD 1 Information
Public Advisory (NHC)


Thursday, June 08, 2006

Announcing the new Yahoo Group!

Since absolutely NOTHING is happening weatherwise in the Mid-South, I decided that it would be a good time to begin a Yahoo Group. It is called "Mid-South Weather" (catchy, isn't it?) and its home page is located at http://groups.yahoo.com/group/midsouthweather. When you join this, you can talk to many people about the weather in our area (when people join). So, tell all your friends - the Mid-South Weather Yahoo Group has begun! You can sign up painlessly by using the box to your right.

Wednesday, June 07, 2006

Severe weather this evening

Sorry for just now posting - I have been busy.

Currently, some severe thunderstorms are moving through western Tennessee. So far, there has been a Mesoscale Discussion, two Significant Weather Advisories (Carroll Co. and Henderson Co.), and four Severe Thunderstorm Warnings (Carroll [2 separate warnings], Henderson, and Chester/McNairy). There are presently no watches in effect for our area.

There has been one storm report tonight. Several truck drivers near Wildersville, TN reported 1" hail at 7:01 PM. They were driving through the storm (obviously).

Looking at the NWS radar, there is currently just one important cell - it is primarily in McNairy County. It has weakened from its severe state eariler this evening. I think that this will be the end of our severe weather for the night.

Tuesday, June 06, 2006

Update on severe weather possibility

As promised, here is my revisit to the severe weather possibility tomorrow. The SPC has placed all of west Tennessee, north Mississippi, and the counties in eastern Arkansas south of I-40 under a slight risk for severe weather in its Day 2 Outlook. They say that "damaging wind gusts and hail will be the primary threats across these regions mainly during the afternoon and evening hours". The NWS office in Memphis agrees with this - they say basically the same thing in their Hazardous Weather Outlook.

Time for the forecast models. The ETA's CAPE values (3000) seem to be greatest in western TN (from Jackson going east) at 7:00 PM. They fizzle out after 10:00 PM. Also, around that time, we will be seeing dewpoints upwards of 70 across all of west TN and most of north MS.

Though the risk is definitely not big, there will still be some instability to create some thunderstorms, some of which will probably be severe. Stay tuned tomorrow for more information.

NWS Memphis receives new employee

The June 5 edition of the NWS Focus, a publication for employees of the National Weather Service, reports in its "New Appointments" section that on May 28, our local office hired Carolyn Glover, who will be an Administrative Assistant. According to the Spring 2006 edition of the Mid-South Chronicle, the former Administrative Assistant, Virginia Johnson, retired from the NWS on March 31 after 21 years working in the government.

Monday, June 05, 2006

Small chance of severe weather Wednesday

According to NWS Memphis's AFD (Area Forecast Discussion), all of eastern AR and the counties in TN bordering the Miss. River could see some severe weather after midnight Wednesday, and the thunderstorms could linger until the morning. It is a pretty slim chance, according to the SPC's Day 2 Outlook, holding it at 15%.

Looking at the forecast models (thanks to WxPortal), I really don't think that any severe weather, if it happens, will begin until after 10:00 AM. There are no CAPE or lifted index values across the area until that time. However, the current run of the ETA only goes out until 1:00 PM CT, so I'll have to wait until tomorrow to give you more specifics, but it's looking like there will be a better chance for severe weather in the afternoon. The GFS can't help us out because there is a big chunk of the data missing, but it seems to be generally be saying the same thing as the ETA.

I'll give you more information tomorrow when more data is available.

Amber Alert

Here is an Amber Alert from Austin, TX:

BULLETIN - EAS ACTIVATION REQUESTED
CHILD ABDUCTION EMERGENCY...CORRECTION
TEXAS EMERGENCY MANAGEMENT AGENCY AUSTIN TEXAS
RELAYED BY NATIONAL WEATHER SERVICE FORT WORTH TX
1100 AM CDT MON JUN 5 2006

...AMBER ALERT...

THIS IS A CHILD ABDUCTION ALERT ISSUED BY THE TEXAS AMBER ALERT NETWORK.

***CORRECTION - PHONE NUMBER FOR LUBBOCK POLICE DEPARTMENT***

THE LUBBOCK POLICE DEPARTMENT IS SEARCHING FOR PRICILLA NICOLE MALDONADO. ...DATE OF BIRTH...MAY 31...2006...18 1/4 INCHES...5.5 POUNDS...WHITE. ...FEMALE...BLACK HAIR...BROWN EYES...AND WEARING A DIAPER...WHITE SOCKS...WRAPPED IN A BLUE RECEIVING BLANKET.

POLICE ARE LOOKING FOR LISA STEWART...30 TO 40 YEARS OF AGE...WHITE....FEMALE...DIRTY BLONDE HAIR...AND WEARING A RED DRESS WITH YELLOW DAISIES AND BLACK SANDALS IN CONNECTION WITH HER ABDUCTION.

THE SUSPECT IS DRIVING A RED PONTIAC 4 DOOR OR A WHITE VAN.

THE SUSPECT WAS LAST HEARD FROM IN LUBBOCK TEXAS.

LAW ENFORCEMENT OFFICIALS BELIEVE THIS CHILD TO BE IN GRAVE DANGER OR IMMEDIATE DANGER.

IF YOU HAVE ANY INFORMATION REGARDING THIS ABDUCTION...CALL THE LUBBOCK POLICE DEPARTMENT AT 806-775-2788.

THE NEWS MEDIA POINT OF CONTACT IS LIEUTENANT ROY BLOCK AT 806-548-3635.

END OF MESSAGE.

Here is a picture of her:

New logos/graphics

To make the affiliation with WxChat, I had to create some graphics for them to use on their site. Here they are. You can use these to link to me, put PLEASE notify me first by posting a comment. I can create custom sizes upon request.

Tiny Button - 88 x 31 -
Location: http://img459.imageshack.us/img459/8192/mswbutton88x318qs.png

Banner - 400 x 60 -
Location: http://img394.imageshack.us/img394/4276/mediummswbanner1jj.png

These images are to be used only with permission of yours truly.

Blogger having problems today, may see outages

UPDATE: New info from Blogger Status:
There is still some residual slowness as a result of emergency maintenance we are performing on the system.
ORIGINAL POST: Blogger is having some problems today due to a hardware problem. As a result, all or parts of this blog may go down today. Here is what Blogger says (status.blogger.com):

We are now recovering from an unscheduled downtime, related to the problem from last week [a hardware problem]. We have obtained more information about the problem and will be working to prevent it from re-occuring.

Also, when this is fixed, I will fix the WxChat banner so that it does not go out.

Sorry for any problems that happen today.

Jake

Who is the newest affiliate of WxChat.com?

WE ARE! Effective today, Mid-South Weather will become a bona fide affiliate of WxChat.com. This mainly means that we put a banner for them on our home page and they do the same for us (thus the lofty banner at the top of this page). Be sure to visit their site at wxchat.com.

Questions? We have answers! Post a comment. (No, that is NOT RadioShack's motto.)

Sunday, June 04, 2006

Rain showers moving through area

A few light showers are moving across the entire Mid-South this afternoon. These showers will usually be light in nature but may produce some CG (cloud-to-ground) lightning. These showers will end tonight, and it will be clear until Monday night.

Saturday, June 03, 2006

Looking for related websites/blogs to link to

If you desire to link to this blog, I would gladly add a reciprocal link under my "Links" section for your site or blog. The only rule is that you must be a weather-related website or blog and/or be a blog or website about something in the Mid-South area.

To request a reciprocal link, simply post a comment with your email address on this post. Don't worry - no one else will see it because I have comment moderation enabled. This means that all comments posted must be approved by yours truly before they will appear on this blog, and none will be approved for this post.

If the requirements don't apply to you but would still like to request a reciprocal link, go ahead and comment. I will probably approve it, anyway.

Friday, June 02, 2006

Sorry for not posting for a few days

I am terribly sorry for not posting since Tuesday. First, I was on vacation in Destin, FL, where my family had an AWESOME time. Second, my stupid DSL connection was down, so even if I was here, I couldn't have posted anyway. Luckily, it works now.

I don't know anything about the weather at the moment as I have within the past hour just gotten in from Destin. I will post more in a few hours.

And, yes, I know that the template has gone haywire. I will fix that in the coming hours.

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© 2005-2007 by Jake Hughes. Some rights reserved - see below.

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