By Aila Boyd aboyd@ourvalley.org
The Botetourt County Department of Fire and Emergency Medical Services (EMS) held a free informative presentation called Skywarn: Storm Spotting and Weather Safety last Tuesday at the Greenfield Education Center in Daleville.
It was billed as being for anyone interested in weather or becoming an official storm spotter. Phil Hysell, warning coordination meteorologist from the National Weather Service in Blacksburg, led the evening.
Members of the community, in addition to meteorology students from Virginia Tech, attended the presentation. Hysell noted that Virginia Tech was the first university in the state to be recognized as a StormReady University when it achieved that status in 2010.
Those who stayed for the entire two hours received a Spotter Certificate.
The presentation focused on the basics of thunderstorm development, the fundamentals of storm structure, identifying potential severe weather features, what information should be reported and how to report it, and the basics of severe weather safety.
At the beginning of his presentation, Hysell noted that spotters, who he called “our eyes in the field,” are needed because when people hear that a severe weather event has been verified by a Skywarn Spotter, they are more likely to take updates from the National Weather Service more seriously. He added that unless someone works in law enforcement or the medical field, being a severe weather spotter is often the closest people come to being able to save someone’s life.
Hysell explained that the National Weather Service is part of the National Oceanic and Atmospheric Administration, which is actually a branch of the Department of Commerce, a fact, he said, few people are aware of. The rationale behind it being part of the Department of Commerce is that weather greatly affects commerce and economic growth. Originally, the Weather Bureau, the National Weather Service’s predecessor organization, was part the Department of War and later the Department of Agriculture. The Weather Bureau became the National Weather Service in 1970.
The National Weather Service in Blacksburg, which is open 24 hours a day and seven days a week, issues hourly weather forecasts for a seven-day period for 40 counties across three different states, watches, warnings, advisories, river forecasts and summaries, climate summaries, fire weather forecasts, and aviation forecasts.
Hysell explained that although his office greatly appreciates it when people who are Skywarn Spotters call in sightings of severe weather, the last thing he wants is for them to put themselves in harm’s way. The best way to avoid danger is to create a buffer zone between oneself and a storm in order to account for any changes in the storm’s movement.
He stressed how simple and easy it is to call in a weather event by noting that it can be done in as little as 10 to 15 seconds. When calling in a severe weather sighting, spotters are asked to answer four questions, all of them starting with the letter “W.” The questions include:
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Who are you?
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What have you witnessed?
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When did the event occur?
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Where did the event occur?
To practice calling in a severe weather event, Hysell presented a photo that depicted a storm and asked for a volunteer to pretend as though they had spotted the storm and were attempting to report it to the National Weather Service. Hysell played the role of the call center operator, while a meteorology student from Virginia Tech pretended to be a concerned Skywarn Spotter.
The presentation covered every severe weather event that Hysell’s office is interested in hearing about, including:
Tornadoes
Hysell explained that a tornado is defined as “a violently rotating column of air that extends from the cloud to the ground.”
The best place to be when a tornado strikes is in a basement with an emergency supply kit. If seeking shelter in a basement isn’t an option, an interior room without windows is the next best option. Hysell noted that top floors should especially be avoided.
When reporting tornadoes, Hysell said that the National Weather Service wants to know where the damage was observed, the length of time that the tornado was on the ground, the time that the tornado started and stopped, the width of the tornado, and how far it traveled.
In order for those in attendance to understand the different tornado terminology that the National Weather Service uses, Hysell explained the differences between tornado watches, warnings, and emergencies. A tornado watch is defined as having weather conditions that could lead to the formation of severe storms and tornados. Tornado warnings indicate that a tornado has been spotted or indicated by weather radar. Tornado emergencies are extremely rare and are issued when a violent tornado has been observed that could threaten human life and cause catastrophic damage.
Flash Flooding
“Turn around, don’t drown,” Hysell said. He explained that flash flooding, which occurs more frequently at night, is the No. 1 storm-related killer in Virginia, as well as the nation. He added that as little as 18 inches of flowing water can sweep a vehicle off the road.
When reporting flash flooding, one should report the approximate water depth of flooded roadways and waterways, whether the water is standing still or flowing, if the water level is continuing to rise, whether the flooding is occurring in a known flood prone area, and whether the flooding has caused any damage.
Wall Clouds
Wall clouds should be reported if they are rotating. The length of time that they have existed should be indicated in the report.
Funnel Clouds
A funnel cloud occurs when the rotating column of air does not make it to the ground. Attention should be particularly paid to organization, persistence, and rotation.
Lightning
Lightning should only be reported when damage or injuries occur. When reporting lightning, calls should only be made on cordless phones.
As for keeping safe, Hysell noted that “when thunder roars, go indoors.” If a shelter isn’t available, he said that a hard-topped vehicle is the next best thing. He added that people should remain indoors for at least 30 minutes after the last thunderclap.
Severe thunderstorm watches are issued for areas where severe thunderstorms could possibly occur. Severe thunderstorm warnings indicate hail one inch in diameter or larger and winds 58 miles per hour or greater.
Winter Weather
Winter weather should always be reported, whether it be freezing rain, ice accumulation, or snow. When reporting it, Hysell said, spotters should note how much heavy snow accumulation there is, any damage that might have been caused by the winter weather, and if blizzard conditions exist. Blizzard conditions are defined as 35 mile per hour winds and quarter mile or less visibility.
Wind
Due to the fact that it’s oftentimes difficult to estimate wind speed, it was noted that a detailed description of moving objects and damage is very useful for the National Weather Service.
When reporting tree damage spotters should reference the following: the height and diameter of the branch, limb, or tree that was broken or blown down, whether the tree was healthy or decayed, and what type of tree was damaged. Hysell said that a good point of reference for reporting diameter of broken limbs is the size of a wrist or arm if actual measuring equipment isn’t available.
If damage has been done to a structure as the result of wind, the following should be included in reports: whether the damaged structure was well built, what type of building was damaged, and if the structure was a mobile home.
Hail
Hysell said hail, which can fall at speeds of up to 100 miles per hour, of any size should be reported. In order to do so, he asked that spotters report the largest hailstone and compare it to the size of a well-known object such as a coin or ball. He said that in the past people compared hailstones to marbles, but due to the fact that marbles come in many different sizes, doing so became problematic.
He recounted a story from his time working for the National Weather Service in Kansas when a woman called in and compared the hailstones that were battering her dwelling to the size of “Aunt Mildred’s nose.” The story received quite a bit of laughter. He added that when calling to report hail, use a measurement that can be universally understood.
Severe hail is designated as being one inch in diameter or larger.
Marine Hazards
The following marine hazards should be reported: waterspouts, squall lines, heavy freezing spray, wave heights that differentiate significantly from forecasted conditions, hydrometeorological phenomena that are not in the current marine forecast, waves greater than twice the size of surrounding waves, tsunami inundation and damage, coastal flooding, lakeshore flooding, and high surf.
Other Environmental Hazards
Other environmental hazards that should be reported include dense fog, dust storms, volcanic ash accumulation or damage, and any injuries or fatalities that occur as a direct result of weather.
Hysell also discussed the four different types of storms:
Single Cell
The lifespan of a single cell storm, which usually isn’t strong enough to produce severe weather, is generally 20 to 30 minutes.
Multi-cell Cluster
Multi-cell clusters, the most common type of storm, can produce heavy rain, winds, hail, and weak tornadoes. They are comprised of groups of individual cells moving as one unit and are more well organized than single cell storms. Individual cells last 20 minutes, but clusters can last for multiple hours.
Squall Line
Squall lines create storms that are linear in structure and can be more than 100 miles long. Although squall lines can produce hail and weak tornadoes, the biggest threat that they pose are straight line damaging winds.
Types of squall lines include roll clouds and derecho, which is a “squall line on steroids.” Derecho is Spanish for straight line.
Supercell
Supercell storms, which are the strongest and longest lasting type of storm, are responsible for the majority of tornadoes in the country. They produce extreme winds, flash flooding, and large hailstones.
Although certified Skywarn Spotters were given a special phone number to use in order to submit sightings of severe weather, Hysell said that the general public is encouraged to contact the National Weather Service if they see anything that meets the requirements that he laid out in his presentation. The public can report sightings by calling 412-262-1988 or by visiting the Report Severe Weather page on the National Weather Service’s website.
