Severe Weather and Storm Chasing
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Severe Weather and Storm Chasing A behind the scenes look at what went on during a chase from June 7, 2009 AOS 121 November 2, 2009 Vortex 2 photogrammetry
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Severe Weather and Storm Chasing. A behind the scenes look at what went on during a chase from June 7, 2009 AOS 121 November 2, 2009. Vortex 2 photogrammetry. Thunderstorm Process. Air that is warmer than its surroundings is positively buoyant and will rise. - PowerPoint PPT Presentation
Transcript of Severe Weather and Storm Chasing
Severe Weather and Storm Chasing
A behind the scenes look at what went on during a chase from June 7, 2009
AOS 121November 2, 2009
Vortex 2 photogrammetry
Thunderstorm Process
• Air that is warmer than its surroundings is positively buoyant and will rise.
• As air rises, it does expansion work, and cools.– Dry Adiabatic Lapse rate ≈10oC/km– Moist Adiabatic Lapse rate ≈6.5oC/km
Thunderstorm Process Cont’d
• Using a Skew-T diagram, we can see the effect of lifting a parcel of air from the surface.
• If the surface parcel is warmer, it is likely to rise and form a thunderstorm.
Atmospheric Soundings and Skew-T Diagrams
Moist Adiabats
Dry Adiabats
Temperature
Mixing Ratio
T = TemperatureTd = Dewpoint
Lifting Condensation Level ~830mb
Level of Free Convection ~ 660mb
Level of Neutral Buoyancy ~ 280mb
Convective INhibition
Convective Available Potential Energy
LCL
Real World ExampleJune 19th Sounding from Davenport IA
Summary
• A Saturated parcel will cool at a slower rate than a Dry air parcel.
• Convective Available Potential Energy measures the amount of potential energy in the atmosphere.
• By understanding Skew-T diagrams, we can predict when severe weather may occur.
Storm Chasing Objective
• Identify weather patterns that will produce rotating thunderstorms.
• Find a storm that will produce a tornado, and be a safe distance away, yet close enough to see it…
Sound easy???
NO WAY!!!• A long-lived tornado is on the ground for 10
minutes, and its path length is only a few miles.
• Most tornadoes are on the ground less than 1 minute.
• If you are on the wrong side of the storm, all you will see is hail crushing your windshield.
• Needle in a Haystack.
Long term Forecast (3 days)
• Look at large scale patterns
• Storm Prediction Center (SPC)
Short term Forecast (day of)
• Look smaller features– Fronts– Clouds– Balloon soundings– Base support
• Storm Prediction Center (SPC)
ComparisonLong range Short range
Morning Outlook
Tornado Hail
Our Chase
Satellite
NWS KC7:15 PM
Radar
NWS KC6:45 PM
Little Hail
Big Hail!!!!
Storm Reports
More Pictures
Acknowledgements• NWS Kansas City Office• Storm Prediction Center• Storm Chasing Class ‘09
Questions
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