Sensitivity of North America Monsoon Convective Precipitation Flooding in Arizona to the Atmospheric Boundary Layer and Circulation
Faculty Mentor Name
Dorothea Ivanova
Format Preference
Poster
Abstract
In September 2014, remnants of Hurricane Norbert brought record-setting rainfall that swept across the Southwest U.S. Flash flooding in Phoenix caused major damage to infrastructure, roadways, and many human casualties including two fatalities. The Phoenix flash flood of September 7-8th, 2014 resulting from the hurricane Norbert is investigated in this Weather Research and Forecasting (WRF) modeling study. Our goal is to simulate the general features of the boundary layer in Arizona prior and during the flash flood events and to study the related hazardous weather patterns. Remnant storm bands from Norbert crossed the core Phoenix metropolitan area, and a record 5.51 inches of rain fell over the Chandler area in just under seven hours. This was the highest recorded rainfall amount since 1895 for the Chandler area. Warmer than normal sea surface temperatures helped to maintain the intensity of the storm. According to NOAA, this was a once in 200 year period event. Our WRF modeling study supports the hypothesis that higher than usual for early September SSTs significantly enhanced the intensity of Norbert and influenced rainfall rates and intensity of the flash flood. To test this, we investigate boundary layer and the atmospheric circulation in Arizona before and during the heavy rain events. Both the boundary layer water content and CAPE over Maricopa County, and the atmospheric circulation over Arizona changed dramatically over the course of the numerical simulations. WRF ARW (Advanced Research WRF model) successfully simulated the boundary layer properties and CAPE during the flood.
Sensitivity of North America Monsoon Convective Precipitation Flooding in Arizona to the Atmospheric Boundary Layer and Circulation
In September 2014, remnants of Hurricane Norbert brought record-setting rainfall that swept across the Southwest U.S. Flash flooding in Phoenix caused major damage to infrastructure, roadways, and many human casualties including two fatalities. The Phoenix flash flood of September 7-8th, 2014 resulting from the hurricane Norbert is investigated in this Weather Research and Forecasting (WRF) modeling study. Our goal is to simulate the general features of the boundary layer in Arizona prior and during the flash flood events and to study the related hazardous weather patterns. Remnant storm bands from Norbert crossed the core Phoenix metropolitan area, and a record 5.51 inches of rain fell over the Chandler area in just under seven hours. This was the highest recorded rainfall amount since 1895 for the Chandler area. Warmer than normal sea surface temperatures helped to maintain the intensity of the storm. According to NOAA, this was a once in 200 year period event. Our WRF modeling study supports the hypothesis that higher than usual for early September SSTs significantly enhanced the intensity of Norbert and influenced rainfall rates and intensity of the flash flood. To test this, we investigate boundary layer and the atmospheric circulation in Arizona before and during the heavy rain events. Both the boundary layer water content and CAPE over Maricopa County, and the atmospheric circulation over Arizona changed dramatically over the course of the numerical simulations. WRF ARW (Advanced Research WRF model) successfully simulated the boundary layer properties and CAPE during the flood.