Validation of Satellite-based Rainfall Estimates for Severe Storms (Hurricanes & Tornados)
Nasim Nourozi, NOAA-CREST/CUNY, New York, NY; and S. Mahani and R. Khanbilvardi
Severe storms such as hurricanes and tornadoes cause devastating damages, almost every year, over a large area of the United States. More accurate forecasting of intensity and track of a heavy storm can help to reduce if not to prevent its damages to lives, infrastructure, and economy. Estimating accurate high resolution quantitative precipitation (QPE) for a hurricane is still a challenging problem because of its physical characteristics, especially when it is still over the ocean. Satellite imagery seems to be a valuable source of information for estimating and forecasting heavy precipitation and also floods, particularly over high mountains and oceans where the traditional ground-based gauge and radar techniques cannot be applied. To improve the capability of a rainfall retrieval algorithm to estimate and predict more accurate QPE of severe storms, the quality of the model output must be evaluated against the observations.
High (hourly 4-km x 4-km) resolution satellite infrared-based rainfall product, from the NESDIS Hydro-Estimator (HE) algorithm, has been examined against NEXRAD stage-IV measurements and rain gauge observations, for hurricanes, in this project. Three strong hurricanes: Charley, Jeanne, and Frances from the summer 2004 and also two very strong hurricanes Katrina and Wilma from the summer 2005, that caused devastating damages over Florida and New-Orleans, have been considered to be investigated. Preliminary results, demonstrate that: 1) for all hurricanes except for hurricane Charley, HE tends to underestimate rain rates especially when NEXRAD shows a heavy storm; 2) radar measurements show a few peaks of heavy rainfall for hurricanes Frances, Jeanne, and Wilma but HE shows a big underestimation at the time of the peaks; 3) HE tends to overestimate the amount of rainfall for the hurricane Charley, in general. HE rainfall product for the selected hurricanes will be validated against hourly rain gauge observations as well.
Poster Session 1, Precipitation/Storm Surge/Flooding
Tuesday, 25 April 2006, 1:30 PM-5:00 PM, Monterey Grand Ballroom
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