Using Ensemble Analysis to Investigate the Genesis of Hurricane Karl (2010)

Hurricane Karl was a category 3 storm on the Saffir-Simpson scale with a minimum central pressure of 956 hPa and maximum sustained winds of 110 knots. Karl formed at 18.1 N, 83.6 W (approximately 2200 km WNW from Barbados) on September 14th at 18Z which originated from a broad low-pressure system that formed from the interaction between a westward propagating wave and an elongated trough of low pressure that extended all the way to northern South America. The use of observations collected from 2010 field campaigns such as NASA's GRIP and the NSF's PREDICT, is used to better understand Karl's genesis. As part of the NASA GRIP field campaign, atmospheric observations (thermodynamic and dynamic) were carried out at Husbands St. James, Barbados (13.1° N, 59.1° W), recording data associated with the pre-Karl disturbance every 3 hours from September 9th 18Z to September 12th 00Z. is assimilated into the Weather Research and Forecasting (WRF) numerical weather prediction (NWP) model by the Ensemble Kalman Filter (EnKF) data assimilation (DA) method and will be presented.