Be Weather Alert

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Be Weather Alert!
January 2009
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Georgia 2008 Year in Review
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East Metro Has 50 Thunderstorms Yearly
http//www.srh.noaa.gov/srh/jetstream/tstorms/tsto
rms_intro.htm
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Watch vs. Warning

• A WATCH identifies a relatively large area in
  which flash floods or severe storms might occur.
  The watch is only an indication of where and when
  the severe weather probabilities are the highest,
  and should not be confused with a warning.

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Watch vs. Warning

• A WARNING is issued when severe weather has
  already developed and has been reported by
  spotters or indicated by radar. Warnings are
  statements of imminent danger and are issued for
  relatively small areas near and downstream from
  the severe storm or flood.
• According to the Chief Meteorologist at Peachtree
  City 2008 set a record of almost 1700 warnings
  issued from that office alone.

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Threats from Thunderstorms

• Thunderstorms cause
• Tornados
• Straight-line wind damage
• Downburst - Microburst
• Hail
• Flash Flooding
• Lightning

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Cumulonimbus(Thunderstorm Clouds)
http//www.srh.noaa.gov/jetstream/synoptic/l3.htm
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Killer Thunderstorms!
Number 1 Killer Flash Flooding 127 deaths per
year
http//www.srh.noaa.gov/srh/jetstream/tstorms/tsto
rms_intro.htm
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Forces on Vehicles from High Water
2007_Basic_Spotter_ILX_web.pdf
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Flash Flooding

• Occurs when rainfall accumulation exceeds 1 inch
  per hour typically associated with severe
  thunderstorms
• Happens within 6 hours of the rain event or as a
  result of a dam or levee failure
• Is most often located at "funneling" points of
  smaller streams or rivers

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Flash Flooding

• Reportable to the NWS when
• Rain is measured to be more than one inch (1") in
  one hour or less
• Small streams are significantly overflowing their
  banks
• Substantial ponding or flowing water on roadways

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Public Enemy 2
Number 2 Killer Lightning 73 deaths per year
http//www.k5kj.net/99091110.jpg
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• Lightning is
• Reportable ONLY if
• Damage to structures or trees
• Extended or wide area power outage
• of Extreme intensity and associated with other
  reportable criteria
• Remember if you
• can hear thunder,
• lightning is a danger!

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Thunderstorm Killers
Number 3 Killer Tornado 68 deaths per year
http//www.photolib.noaa.gov/700s/nssl0210.jpg
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TORNADO
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2007_Basic_Spotter_ILX_web.pdf
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2007_Basic_Spotter_ILX_web.pdf
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Tornados

• Rotating column of air touching the ground
  causing swirls of dust, debris and condensation
• Funnel bounds may not be visible
• May be feet to miles wide
• May exist for seconds to hours
• Storm motion - stationary to moving at 70 mph
• Normally associated with a "strong" "severe"
  "super-cell" thunderstorm

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Thunderstorm Life Cycle
2007_Basic_Spotter_ILX_web.pdf
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Thunderstorm Life Cycle
2007_Basic_Spotter_ILX_web.pdf
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Thunderstorm Life Cycle
2007_Basic_Spotter_ILX_web.pdf
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Tornado Pre-Cursors

• ROTATING WALL CLOUDS
• A cylindrical shaped cloud structure hanging from
  the storm base showing rapid closed rotation
• FUNNEL CLOUDS
• Funnel shaped vortex cloud descending from main
  cloud base, but not touching ground
• However, DO NOT be fooled by
• Virga and / or precipitation shafts
• Smoke columns
• Scud

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Tornado without visible funnel
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Rotating Wall Cloud
Scuds
http//www.kwarc.org/canwarn/June14-04.html
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Wall Clouds
2007_Basic_Spotter_ILX_web.pdf
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Storm damage can't be prevented
http//www.pbs.org/wgbh/nova/tornado/dama-04.html
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BUT

• With WARNING
• More People Can Stay Safe
• Know What to Do!!

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Staying Safe - Lightning

• Lightning poses the greatest threat to storm
  watchers
• If you are close enough to hear the thunder, you
  are close enough to be struck.
• If possible, move indoors away from windows
• If you are outdoors with no shelter, get into a
  vehicle

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Staying Safe - Lightning
2007_Basic_Spotter_ILX_web.pdf
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Staying Safe - Wind
2007_Basic_Spotter_ILX_web.pdf
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Staying Safe - Tornados
2007_Basic_Spotter_ILX_web.pdf
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2007_Basic_Spotter_ILX_web.pdf
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What Do You Report?

• FROM A SAFE LOCATION
• WHAT you saw
• WHERE you saw it
• WHEN you saw it
• WHAT IT WAS DOING
• Direction Speed Size Destructiveness
• WHO you are
• Name Phone Spotter number Call sign
• CONCISE TIMELY ACCURATE

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ALWAYS REPORTABLE

• If it Spins Call it in!
• TORNADOS
• Rotating Wall Clouds
• Funnel Clouds

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Do NOT Report

• Rain less than 1 inch per hour or of short
  duration
• Lightning, if no damage
• Wind less than 40 miles per hour
• Hail smaller than penny sized (lt 3/4)
• Situations with authorities already present
• Information heard on official radio channels
• Police / fire / EMS / utilities
• Information determined to be duplicative
• Un-authenticated / second-hand information

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SEVERE, REPORTABLE and NOT A TORNADO

• Hail
• 3/4 inch or greater
• Penny sized or larger
• Wind
• Prefer measured speed
• Greater than 40 mph (5 second average)
• Downed trees (multiple)
• Downed power lines
• Damage to structures
• Trees stripped of leaves and growth twigs

http//www.chaseday.com/hailstones.htm
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2007_Basic_Spotter_ILX_web.pdf
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Fujita Scale vs. Enhanced Fujita
2007_Basic_Spotter_ILX_web.pdf
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Reporting Methods
Direct to NWS Peachtree City by
phone [phone] Direct to
NWS via e-mail (http//eSpotter.weather.gov
) 770-763-1133 -- if all else fails
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eSpotter Report Form - top
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eSpotter Report Form - bottom
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http//www.srh.noaa.gov/ffc/
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Be Even More Effective!!
Strengthen Your Skills With A SKYWARN CLASS
For the next NWS SKYWARN classes, check online
at Georgia SKYWARN http//www.georgiaskywarn.
com/
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For more information

• 2009 Schedule for Georgia Spotter Classes
  http//www.srh.noaa.gov/ffc/html/sched.shtml
• Georgia SKYWARN
  http//www.georgiaskywarn.com/
• Getting Started in Tornado and Thunderstorm
  Spotting -- http//www.srh.noaa.gov/oun/skywarn/sp
  otterhelp.php
• Basics of Storm Spotting http//www.srh.noaa.gov/o
  un/stormspotting/basics.php
• Data in this presentation acquired from
  www.weather.gov

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Thank you