I want you as a SKYWARN weather spotter

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I want you as a SKYWARN weather spotter
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The answer is Yes!
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NWSs Nationwide Coverage
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Pueblos County Warning and Forecast Area
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The National Weather Service does three things

1. Observes the weather
2. Predicts the weather
3. Informs you on what we have discovered

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Three Tier Philosophy for non-routine forecasts

• Ready - Hazardous Weather Outlook
• Set - Watches
• Go - Advisories Warnings

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Doppler radar facts
Power 750,000 watts Antenna 28
foot Frequency 3 GHz Beam Width 0.93
degrees Wave Length 10 cm Pulse Rate 1304 /
sec. Transmitter 1 to 3 sec / hr Receiver 2x10-
14 watts
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NWS Doppler Dish

• The radome protects
• the 28 foot diameter
• dish (shown here),
• which operates 24
• hours a day,

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Radar Datawww.crh.noaa.gov/pubclick on Pueblo
under radar imagery
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Radar Datawww.crh.noaa.gov/pubclick on Pueblo
under radar imagery
Reflectivity - dbZ returns at the 0.5 degree
elevation slice
Composite
Reflectivity - HIGHEST dbZ return in each sampled
vertical column One-hour precipitation - the
total estimated precipitation for the past hour
from the most recent scan Storm total
precipitation - the total estimated precipitation
since the radar went into precipitation mode
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The warning processit takes teamwork
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NOAA Weather RadioThe voice of the National
Weather Service
Direct from the National Weather Service to
your home school business campsite
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Its good to be CONNECTED
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The Warning Process
Mobile Spotters
Emergency Services
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Importance of Spotters
Warning Decision Tree Typically, we need 2 of the
following 3 to issue a warning - radar
confirmation - near storm weather - spotter
information
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Spotters Mission
OBSERVE with trained eyes AND REPORT...either
from a fixed location or mobile. The objective
is to provide weather information that the NWS
and Emergency Management can use to protect life
and property.
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What is a Severe Thunderstorm ???
3/4 hail - penny size or bigger



58 mph winds or higher
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What to Report
Hail of ANY size
Winds of 58 mph or higher
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What to Report
Flash Flooding or High Water
Microbursts
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What to Report
Tornado or Funnel cloud
Persistent, rotating wall cloud
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The Warning Process

• Hail card

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What is the difference between a funnel cloud and
a tornado ???
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Funnel cloud or tornado ???
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Funnel cloud or tornado ???
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Funnel cloud or tornado ???
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The Warning Process

• Our office observes and predicts weather, and
  then INFORMS the public of our findings. To do
  the best job of INFORMING, we
• NEED accurate, real time
• COMMUNICATION with weather spotters.
• Weather information MUST be relayed to the NWS
  from our volunteer weather spotters ASAP.

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The Warning Process
Doppler radar shows warning forecasters the
intensity of rain, estimates the size of hail,
and evaluates the wind structure around and
within thunderstorms, BUT...Doppler radar CANNOT
tell warning forecasters exactly what is
occurring on the ground !! Weather spotters
are the warning forecasters eyes, and confirm
what he or she thinks is occurring on the ground
under the storm cloud. At times, with this exact
information...the warning forecaster can decide
whether to issue a warning, or whether to
continue an existing warning.
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Doppler Radara great tool, with some important
limitations
- Radar beam is high above the ground at farther
ranges. - Difficult to detect tornadic scale
motion, especially at far ranges. - Cannot tell
if the circulation is on the ground. - ESTIMATES
hail size. Spotters can fill in the blanks!
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Radar Beam 0.5o tiltBeam elevation above
ground level (in feet)
9200
2400
1600
7200
7500
2700
2100
5900
3400
8400
2500
4600
9600
4200
9400
11500
9400
12300
8500
7400
15000
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A Weather Scenario
The warning forecaster sees a storm which, on
radar, looks like it IS producing hail around 1 ½
inches in diameter and shows a moderate, shallow
rotation within the storm. He only issues a
severe thunderstorm warning for the hail, but
wonders if the rotation is creating any cloud
features at or under the base of the storm. A
minute later a spotter calls in and says she is
watching a funnel cloud a few thousand feet above
the ground. The spotter continues to hang on the
line with the warning forecaster for several
minutes, describing in detail the behavior of the
funnel cloud. Then, the warning forecaster
notices that the storm, on radar, is showing less
rotation several thousand feet above the ground.
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A Weather Scenario
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A Weather Scenario
Action taken the warning forecaster decided NOT
to issue a tornado warning. A severe
thunderstorm warning remained in effect for hail
bigger than the size of quarters. The funnel
cloud dissipated, and the public was well served.
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The Warning Process

• Accurate, real-time communication makes it work

Who Where What When
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WX0PUB
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The Warning Process
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How do we use your spotter reports ???
Three Critical Uses for Spotter Reports. 1)
Issuing or NOT issuing a warning in the warning
process. 2) Specific input to follow-up
statements that can spur people on downstream to
take cover.





3) Verification and Storm Data
records.
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Tree Limbs Down
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Trees Down
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Please do NOT say
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funnel on the ground
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Lightning Processes
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Riming supercooled water droplets changing to
ice on cold surfaces
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Riming causes ice crystals in a thunderstorm
updraft to morph into GRAUPEL
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Charge Separation Process
Lighter ice crystal
Heavier graupel
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Lightning Flash Density
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Lightning Flash Density
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CG Flashes per year x 1000
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Percent of Positive Flashes
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Colorado CG Lightning Stats

• Flashes per year 499,888
• (rank of 15th out of 48 states)
• Flashes per square mile 4.8
• (rank of 28th out of 48 states)
• Death rate per million people 1.04
• (rank of 11th out of 48 states)

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Safety Above All Else
- Your life is more important than any report. -
You should know the storms hazardous weather
history. - If you are mobile, it is absolutely
critical that you are aware of your location
and how that relates to the location, track,
and speed of the storm. - If you are mobile,
try to stay away from the storms hazards, and
remain in your vehicle.
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Safety Above All Else

• Lightning Safety

In most years it is the 2 weather hazard
Lightning is the 1 weather hazard for spotters
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Safety Above All Else

• Lightning Safety

Lightning can travel many miles beyond the edge
of the rain area of a storm At best, thunder
can only be heard about 12 miles away from the
lightning flash If you can hear thunder, youre
close enough to be struck by lightning!
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Deadly lightning
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End of Part One

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