1. The Influence of a Precursor Central American Gyre and a Northerly Gulf of Tehuantepec Surge on the Formation of Hurricane Patricia in October 2015
Lance Bosart1, Philippe Papin1, Andrew Levine2, and Alicia Bentley1
1Department of Atmospheric and Environmental Sciences
University at Albany, State University of New York
2NOAA/National Hurricane Center, Miami, FL
32nd Conference on Hurricanes and Tropical Meteorology – 18 April 2016

2. Motivation
TC Patricia in the east Pacific is the strongest hurricane ever recorded in the Western Hemisphere (185 kt, 872 hPa)
Its development resulted from a complex interaction of different scale features
Active phase of ENSO/MJO
Predecessor Large Scale Circulation
Gap Winds in the Gulf of Tehuantepec
These features resulted in significant flooding and societal impact before Patricia developed
Focus on the synoptic and mesoscale evolution that preceded Patricia’s development

3. Motivation ITCZ WAVE 1 WAVE 2
850-hPa winds (vectors, m s-1) and curvature vorticity (shading, 10-5 s-1) 0000 UTC 13 Oct 2015
WAVE 1
WAVE 2
ITCZ

4. Motivation
Large low-level cyclonic circulations occasionally form over Central America
Central American Gyres (CAGs)
Tropical Cyclones (TCs) can form within these large scale circulations
TC Patricia (2015)
Strongest hurricane ever recorded in western hemisphere
850-hPa time-mean winds (vectors, m s-1) from 15 Oct – 20 Oct 2015 H
CAG

5. Motivation H
CAG

6. Datasets 0.5o Climate Forecast Center Reanalysis (v2)
0.25o Global Forecast System Analysis
ASCAT Satellite Passes (when available)
Surface METAR Observations

7. Beginnings Continuity Plot: Easterly Wave #1 1200 UTC 16 Oct 2015

8. Beginnings Continuity Plot: Easterly Wave #2 1200 UTC 16 Oct 2015

9. Antecedents
CAG P

10. CAG Development
CAG P
0000 UTC 14 October 2015

11. CAG Development
CAG P
0000 UTC 14 October 2015

12. Gap Winds

13. Patricia’s Development

14. Summary Schematic