Hurricane Norbert

Hurricane Norbert produced a 1-in-1,000 year rainfall event in Arizona in early September 2014. The fifteenth named storm, tenth hurricane, and seventh major hurricane of the 2014 Pacific hurricane season, Norbert originated from an area of disturbed weather in association with an area of low pressure on September 2. Tracking generally northwestward, the newly designated tropical storm steadily organized in a moderate shear environment. Norbert attained hurricane intensity early on September 4 and Category 2 hurricane strength the next afternoon. Thereafter, the cyclone began a period of rapid deepening, and it subsequently attained its peak intensity with winds of and a minimum pressure of early on September 6. A track over progressively cooler waters and into a more stable environment prompted a weakening trend after peak intensity, and by early on September 8, the system no longer maintained enough convection to be considered a tropical cyclone. Meteorological history On August 30, the National Hurricane Center (NHC) indicated the potential for an area of low pressure to form offshore the coastline of Mexico and slowly develop over subsequent days. This projection came to fruition the next afternoon, when a large area of showers and thunderstorms in association with a trough of low pressure was noted. Amid a generally favorable environment with moderate wind shear and warm sea surface temperatures, convection steadily coalesced atop a distinct low-level circulation, and the disturbance acquired enough organization to be deemed a tropical cyclone at 15:00 UTC on September 2; it was designated Tropical Storm Norbert in accordance with an Advanced Scatterometer (ASCAT) pass. Due to moderate northeasterly wind shear, only modest intensification was predicted. Norbert moved generally northwestward succeeding formation, steered around the southwestern periphery of a subtropical ridge across Baja California and northern Mexico. All the while, the cloud pattern of the cyclone progressively improved, with a symmetric central dense overcast and distinct rainbands on convectional satellite, and a formative inner core with hints of a small mid-level eye on hurricane imagery.