Tuesday, 12 January 2016: 11:45 AM
Room 338/339 ( New Orleans Ernest N. Morial Convention Center)
Hurricane PATRICIA was a small, extremely powerful hurricane that devastated villages along the Jalisco coast of Mexico. At the time of this writing, questions remain about the exact landfall intensity of PATRICIA, as well as the intensity of the Great Mexico Hurricane of 1959 (currently being reanalyzed). Despite these unknowns, PATRICIA is likely the most-intense hurricane landfall in the history of the E Pacific basin and the W coast of Mexico. Official data from the landfall region were sparse to nonexistent. Fortunately, the iCyclone team was in Emiliano Zapata (19.38973N 104.96391W)—very close to the hurricane's landfall point—to document this extreme, historic impact. There we collected continuous, quality-controlled data and timestamped video footage during the entire passage of the cyclone's core. What emerges is a complete record of the event—with interesting conclusions: 1. The hurricane still had an intense, compact core at landfall. Despite weakening prior to landfall, PATRICIA came ashore with a tight, concentrated, extremely violent inner core. Damaging winds only persisted for ~ 2 hours at our location, and peak winds only lasted ~17 minutes. 2. The center passed near or over Emiliano Zapata. A brightening of the sky, partial calming of the winds, and abrupt wind shift roughly coincided with the lowest pressure of 937.8 mb, indicating passage of the eye. This reading is the lowest sea-level pressure ever recorded on land during an Eastern Pacific hurricane. 3. The pressure gradient in the hurricane's inner core was incredible—over 11 mb/n mi in one place. Not surprisingly, the short period of extremely violent winds in the SE eyewall coincided with these peak gradients (see next point). 4. The backside (SE eyewall) was much more vigorous than the front. The SE eyewall packed a ferocious punch, but it didn't last long—passing in about 15 minutes. The front side (NW eyewall) wasn't as vigorous: wind speeds weren't as high, and precipitation was light during some of the strongest winds preceding the eye. This may have been caused by inflow coming off the land during the cyclone's front side. 5. Damage was consistent with the passage of an extremely severe hurricane. Heavy wind damage occurred in Emiliano Zapata and nearby villages that experienced the hurricane's violent core. Most trees were 100% defoliated and/or stripped of branches. Palms were badly thrashed, with some defronded or snapped off at the trunk. The nearby hills—which had been green and jungly before the storm—were left bare. Many houses and buildings lost their roofs or had other structural damage. Concrete power poles snapped; communications towers crumpled. Supporting the above conclusions will be iCyclone's: • Air-pressure traces from two calibrated devices. • Detailed event chronology (reconstructed from time-stamped video footage). • Time-stamped video stills. • Damage imagery from the storm's aftermath. Supplementing these will be NOAA satellite imagery and recon data, as well as all available data from Mexico's Servicio Meteorologico Nacional. Refer to the full iCyclone report (goo.gl/Yn5Ftx) and video (https://youtu.be/V2H1M0n2Q14) for more.
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