Javier Rosa Department of Marine and Environmental Systems Florida Institute of Technology
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Transcript of Javier Rosa Department of Marine and Environmental Systems Florida Institute of Technology
Sea Breeze Initiated Thunderstorms Relating to Convective Available Potential Energy (CAPE) and
Convective Inhibition (CINH)
Javier Rosa Department of Marine and Environmental Systems
Florida Institute of TechnologyMelbourne, Florida 32901
July 16, 2008
Overview
• What is the purpose for this project?• What is CAPE/CINH?• Why look at CAPE/CINH?• How are values gathered?• Where is area of focus for this project?• Is there a threshold for CAPE in thunderstorms?
Purpose
• Find a threshold for CAPE values in thunderstorms initiated by the sea breeze
• Provide ability to forecast sea breeze thunderstorms using CAPE as a predictor
What is CAPE/CINH?
• CAPE is the integrated area of positive buoyancy
• CINH is the integrated area of negative buoyancy
• CAPE = Instability• CINH = Stability
Why look at CAPE/CINH?• CAPE is needed for
thunderstorm development (accelerating motion)
• CINH can limit thunderstorm initiation (decelerating motion)
• Previous study indicated threshold values for CAPE (Solomon, R., and M. Baker, 1994)
Sounding DataLaunched 3 times a
day (5 AM, 11 AM, 5PM)
CAPE = Positive Buoyancy
CINH = Negative Buoyancy
Most Unstable parcel was used for project
CAPE
CINH
North American Mesoscale (NAM) Forecast Model
• NAM is an atmospheric prediction model
• NAM forecast runs every 6 hours with 3 hour forecast intervals up to 84 hours for each run
• 12 km resolution
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Area of Study
• The area of study includes the Cape Canaveral region and its surrounding areas
Methods• Locate sea breeze
thunderstorms using Melbourne radar reflectivity
• Get CAPE and CINH values using sounding data and NAM forecast model
Sea Breeze Boundary
Thunderstorm Initiation
Thunderstorm Initiation
Additional Thunderstorm Initiation
More Storm Initiation
CAPE Statistics Using NAM Forecast Model
-Not statistically different-Cannot differentiate between yes and no cases
CAPE Statistics Using Sounding Data
-Not statistically different-Cannot differentiate between yes and no cases
CINH Statistics Using Sounding Data
-Not statistically different-Cannot differentiate between yes and no cases
Conclusion
• CAPE is not a good predictor of sea breeze thunderstorms based on data set
• CINH was not a factor in limiting thunderstorm initiation
Any Questions/Comments?
Takashi Kida
References• Wilson, J.W., and D.L. Megenhardt, 1997: Thunderstorm
Initiation, Organization, and Lifetime Associated with Florida Boundary Layer Convergence Lines. Mon. Wea. Rev., 125, 1507–1525.
• Weisman, M. L., and J. B. Klemp, 1982: The dependence of numerically simulated convective storms on vertical wind shear and buoyancy. Mon. Wea. Rev., 110, 504–520.
• Solomon, R., and M. Baker, 1994: Electrification of New Mexico Thunderstorms. /Mon. Wea. Rev./, *122*, 1878–1886.