The MAST Corporate Spotter Training Seminar 2005

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The MAST Corporate Spotter Training Seminar 2005
Welcome!
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Introduction

• During the first session we cover the need for
  spotters, the structure of thunderstorms, the
  nature of severe weather, and how to make
  reports.
• We will then take a break.
• We will next cover tornadoes, severe weather
  safety, and how to integrate severe weather
  spotters into a business safety plan.

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Session 1 The Basics
Some thoughts on corporate severe weather
spotting, and the fundamentals of severe weather
meteorology.
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Every Year False Tornado Warnings Cost Business
Millions of Dollars

• Developing a responsible severe weather plan,
  including severe weather spotters, can help keep
  your workers safe, and can save you money.

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Thoughts about Corporate Spotting

• False severe weather warnings cost millions of
  dollars as business grinds to a halt. Failure to
  halt business during an official severe weather
  warning can cost your company a lot in liability.
• Accurate severe weather warnings might not even
  apply to your business, though you are still
  forced to close down.

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Thoughts about Corporate Spotting (continued)

• Trained severe weather spotters can mitigate
  these effects.
• Trained severe weather spotters can tell you when
  a severe storm is approaching.
• Trained severe spotters can warn of approaching
  danger, even in the absence of an official alert.

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Thoughts about Corporate Spotting (continued)

• Trained severe spotters can warn the National
  Weather Service of dangerous weather conditions.
• Trained severe weather spotters can alert the 911
  center to potentially dangerous weather that
  might influence their area of responsibility.

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Training Objectives for Session 1
Understand the reason for spotters.
Understand thunderstorm structure.
Identify and report severe weather.
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The Reason for Severe Weather Spotters

• The most important reason for severe weather
  spotters is, unless the severe weather occurs
  within ten miles of the National Weather Service
  (NWS) forecast office, the NWS can not be certain
  that it exists.
• Well-trained spotters, working with radar data,
  should be able to verify if a severe or tornadic
  storm is approaching your business.

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The Reason for Severe Weather Spotters (continued)

• While Doppler radar is useful, it cannot detect
  rotation near the ground more than ten miles
  away this is because the Earth's surface curves
  away from the radar beam.

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The Reason for Severe Weather Spotters (continued)

• The algorithms used by the Doppler radar to
  calculate the presence of rotation in a storm
  pixelizes the data. Each side of such a pixel is
  about 500 yards long. Most tornadoes are about
  100 yards across thus they would fall within
  such a pixel and not be seen by the radar.

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The Reason for Severe Weather Spotters (continued)

• It is possible for well-trained spotters from
  your business to participate in the over-all
  warning system.
• It is possible for well-trained spotters, under
  appropriate circumstances, to allow your company
  to continue to work during a warning.

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First Discussion

• It is now time to sit down and discuss what we
  have covered so far, ask any questions you have
  not yet asked, and complete our understanding of
  why spotters are important.

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Thunderstorms

• A thunderstorm is a method used by the atmosphere
  for regulating heat from the lower level of the
  atmosphere to the middle levels.

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Thunderstorms (continued)

• Thunderstorms begin as an updraft where moist and
  warm air is drawn upward. When this occurs the
  moisture condenses into a cloud. This
  condensation adds the heat used to keep the
  moisture as a gas that is released when the cloud
  forms.
• If there is sufficient heat and moisture combined
  the updraft can get very tall.

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Thunderstorms (continued)

• If the updraft is tall enough, the droplets that
  form the cloud will coalesce to form large enough
  droplets to make snow or rain (which may begin as
  snow in any case).
• This rain will fall due to the action of gravity.
• The rain will create a downdraft due to drag
  caused by the falling droplets.

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Thunderstorms (continued)

• This downrushing air is called a downdraft.
• The combination of an updraft and a downdraft is
  called a thunderstorm cell.
• When ice crystals collide they can develop large
  accumulations of charge. When these charges have
  differing signs, a potential difference is
  created. When the potential differences get large
  enough lightning results.

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Thunderstorms (continued)

• Here is a classic thunderstorm.

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Thunderstorms (continued)

• Here is a classic thunderstorm.

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Thunderstorms (continued)

• In this type of storm the updraft is in the rear,
  and the precipitation at the top of the updraft
  column is blown downstream by a river of high
  winds called the jet stream.
• This is important, because slow moving storms
  will not last more than 15-20 minutes because
  their own downdraft chokes off the updraft, thus
  cutting off its fuel.

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Thunderstorms (continued)

• When you are in front of the storm, the first
  thing you will feel is a cool breeze coming from
  the storm. Such a breeze is called outflow.
• In severe storms this can attain severe levels
  and is called a gust front. Gusts fronts have
  attained hurricane force (72 mph) or higher.

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Thunderstorms (continued)

• The gust front will likely be accompanied by a
  large outward jutting deck of cloud material
  called a shelf cloud. Here are some examples of
  shelf clouds.

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Thunderstorms (continued)

• The shelf cloud forms as a result of rain-cooled
  air being pushed out ahead of the thunderstorm. A
  good many false tornado and funnel cloud reports
  occur because of dangling cloud matter from the
  shelf cloud. It is extremely rare for a tornado
  to form on the front side of the thunderstorm.

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Thunderstorms (continued)

• Another type of wind event can occur in very
  strong
• thunderstorms. Here
• a glob of rain-cooled
• air descends,
• accelerates, and
• then slams into the
• ground at very high
• speeds. This is called
• a downburst.

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Thunderstorms (continued)

• Another risk from thunderstorms, particularly in
  the downdraft regions, is hail. Large hail can
  cause injury and extensive damage to buildings,
  vehicles, crops, and lifestock.
• Flash flooding is a problem whenever storms have
  a plentiful source of moisture, the ground is
  saturated, and/or the storms are slow moving.

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Second Discussion

• It is now time to sit down and discuss what we
  have learned about thunderstorms, ask any
  questions you have not yet asked, and complete
  our understanding of thunderstorms.

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Identifying Severe Weather

• Officially severe weather is
• Hail 3/4" in diameter of more.
• Winds 58mph or more (50 knots).
• Funnel clouds.
• Tornadoes.
• Flash flooding.
• Nothing else is considered to be severe weather.

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What Kinds of Weather is Reported?

• The NWS wants a report of
• Hail 1/4" in diameter of more.
• Winds 45mph or more.
• Funnel clouds.
• Tornadoes.
• Rotating wall clouds.
• Flash flooding.

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How do you make a report?

• Call the 911 dispatcher
• Give your name, and state that you are a trained
  severe weather spotter.
• Identify the type of report you are making.
• State your location.
• Give the direction of the event you are
  reporting, if it is in a different location.
• State the time the event occurred.

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Stay Safe!

• Safety is our first concern do not make your
  report if you do not feel that you are safe!

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Third Discussion

• It is now time to sit down and discuss what we
  have learned about severe weather and severe
  weather reporting, ask any questions you have not
  yet asked, and complete our understanding of
  severe weather.

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Session 2 Tornadoes
Some thoughts on tornadoes, tornado safety, and
the integration of severe weather spotters into a
business severe weather plan.
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Tornadoes

• A tornado is a violently rotating column of air
  extending from the base of a cloud to the ground.
  There is no need for a visible funnel to reach
  all the way to the ground.

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Tornadoes (continued)

• Tornadoes are most frequently found in the region
  of the updraft of the thunderstorm. Tornado winds
  rotate, but they also have an upward motion fed
  by the updraft.
• The exact process of tornado formation is still a
  mystery. It seems that tornadoes form at or near
  the ground level and build upward.

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Tornadoes (continued)

• Tornadoes are often preceeded by a structure
  called a wall cloud. Here are some wall clouds

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Tornadoes (continued)

• A vortex aloft is called a funnel cloud. They are
  never called tornadoes.

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Tornadoes (continued)

• If you are unable to see the base of a vortex,
  you will need to report it as a funnel cloud.

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Tornadoes (continued)

• Wall clouds form at the point of an intense
  updraft. The wall cloud is the most dangerous
  place in a thunderstorm. It forms as rain cooled
  air is drawn into the updraft, thus it tends to
  tilt towards the downdraft. When the wall cloud
  rotates, it is to be considered very dangerous.

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Tornadoes (continued)

• The rotation of a wall cloud is an indication
  that it represents the bottom of a storm-scale
  rotating updraft called a mesocyclone. If you see
  a rotating wall cloud be certain to call it in.

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Fourth Discussion

• It is now time to sit down and discuss what we
  have learned about tornadoes, wall clouds, and
  funnel clouds, ask any questions you have not yet
  asked, and complete our understanding.

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Tornado Safety Rules

• These rules apply to strong, straightline winds,
  too.
• Since tornadoes have a vertical component to
  their winds, debris can be hurled high into the
  air. This necessitates the first rule of tornado
  safety "Do not let anything fall on you!"
• Even in a basement, things can be deposited on
  top of you.

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Tornado Safety Rules (continued)

• Lying in a ditch, or ravine, many objects can
  fall on you.
• You want to place very sturdy barriers between
  you and whatever might be falling on you from
  dirt to vehicles.
• In a similar way, you do not want anything that
  is flying to hit you.
• You want to place solid barriers between you and
  the wind.

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Tornado Safety Rules (continued)

• This is why basements are a good place to be.
• The vast majority of tornado injuries and deaths
  come from wind-blown debris.
• The second rule of tornado safety is then, "Do
  not let anything that is flying hit you!"

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Fifth Discussion

• It is now time to sit down and discuss what we
  have learned about tornado safety, ask any
  questions you have not yet asked, and complete
  our understanding.

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Merging Spotters Into Existing Severe Weather
Plans

• Check the convective outlooks and mesoscale
  discussion every few hours throughout the day.
  These can be found at www.spc.noaa.gov.
• Should the outlooks or discussions indicate a
  possibility of severe weather, plans should begin
  to go into effect.
• Should a watch be issued, spotters should begin
  to pay attention to local weather.

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Merging Spotters Into Existing Severe Weather
Plans (continued)

• Should storms begin to develop, a spotter should
  continually monitor local radar and keep track of
  the motion of any storms that develop.
• Should a storm be heading your way, then spotters
  should be deployed to warn of approaching severe
  weather. This should trigger existing severe
  weather plans.

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Merging Spotters Into Existing Severe Weather
Plans (continued)

• Should a warning be issued for a specific storm,
  or set of storms, they must be monitored to see
  if they are heading your way. If not, you can
  probably continue to operate safely.

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Final Discussion

• It is now time to sit down and discuss what we
  have learned about integrating spotters into your
  plans, ask any questions you have not yet asked,
  and complete our understanding.

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Additional Services

• The MAST website www.madscitech.org
• Email consultations, george_at_madscitech.org
• Phone consultations at 276-6832.
• Additional training is available upon request.
• Personal consultation.