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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 Technology Melbourne, Florida 32901 July 16, 2008. Overview.
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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 Technology Melbourne, 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 Data • Launched 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 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500
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
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.