HR: 12:05h
AN: H52A-08    [Abstracts]
TI: Hurricanes, Extreme Rainfall, and Subseasonal Predictability for the US, Mexico, and Central America
AU: * Barlow, M
EM: Mathew_Barlow@uml.edu
AF: University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854, United States
AU: Rhoads, J
EM: Jefferson_Rhoads@student.uml.edu
AF: University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854, United States
AB: The influence of hurricanes on extreme daily rainfall events and the potential subseasonal predictability of those events due to the influence of the Madden-Julian Oscillation (MJO) are examined for the US, Mexico, and Central America. More than 15,000 daily precipitation stations from the Global Daily Climatology Network (GDCN) are used to analyze extreme rainfall events. Hurricane and tropical storm locations are taken from the Hurricane Best Track (HURDAT) files of the National Hurricane Center for the Atlantic and Eastern North Pacific, 1974-2000. The Wheeler and Hendon real-time index is used to characterize the MJO activity and the Maharaj and Wheeler approach is used to forecast the MJO. As expected, hurricane activity strongly influences the occurrence of extreme daily rainfall events over large areas of the region and the daily station data provides the maximum resolution of the signal, especially in regions with sparse data coverage. Of particular note are the large spatial scales of the influence of hurricanes in their extratropical stage over land, resulting in the hurricane influence extending considerably further inland than the well-known coastal impacts. Given the previously-established MJO influence on hurricane activity and the link between hurricanes and extreme rainfall events, the MJO influence on extreme rainfall events is examined both for hurricane-related events and for non-hurricane-related events. The MJO influence on daily rainfall extremes in Mexico identified in our previous work is seen to be closely related to the MJO modulation of hurricane activity. The influence of hurricanes and the MJO on flood disasters in Central America and Mexico is examined in terms of societal impact using the EM-DAT disaster database of the Centre for Research on the Epidemiology of Disasters (CRED). Since the MJO is predictable at subseasonal timescales, the MJO influence on extreme events (both hurricane and non-hurricane related) may also be predictable and this is examined at the station level based on the Maharaj and Wheeler MJO forecast.
DE: 1817 Extreme events
DE: 1821 Floods
DE: 1834 Human impacts
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3354 Precipitation (1854)
SC: Hydrology [H]
MN: 2007 Joint Assembly