Hurricane Sergio (2018)

Hurricane Sergio
Category 4 major hurricane (SSHWS/NWS)
Hurricane Sergio shortly after peak intensity on October 4
Formed September 29, 2018
Dissipated October 13, 2018
(Remnant low after October 12)
Highest winds 1-minute sustained: 140 mph (220 km/h)
Lowest pressure 943 mbar (hPa); 27.85 inHg
Fatalities None
Damage Unknown
Areas affected Baja California Peninsula, Northwestern Mexico, Southwestern United States, Texas
Part of the 2018 Pacific hurricane season

Hurricane Sergio was a powerful and long-lived tropical cyclone that made landfall in the Baja California Peninsula as a tropical storm. Sergio became the eighth Category 4 hurricane in the East Pacific for 2018, breaking the old record of seven which was set in 2015. The twentieth named storm, eleventh hurricane, and ninth major hurricane of the season, Sergio originated from a broad area of low pressure formed a few hundred miles south-southeast of the southern coast of Mexico on September 26. The National Hurricane Center continued to monitor the disturbance for a few days until it organized into a tropical storm and was designated as Sergio. Sergio gradually strengthened for the next couple of days, becoming a hurricane on October 2. Sergio then began a period of rapid intensification, becoming a major hurricane later that day. Intensification then halted for about twelve hours before resuming on October 3. The next day, Sergio peaked as a Category 4 hurricane with maximum sustained winds of 140 mph (220 km/h) and a minimum central pressure of 943 mbar (27.85 inHg). Sergio maintained peak intensity for six hours before beginning to weaken. On October 5, the system bottomed out as a low-end Category 3 hurricane. Sergio then began another period of intensification, achieving a secondary peak at Category 3 status on October 6. The next day, Sergio began to weaken again, falling below major hurricane strength. At the same time, Sergio unexpectedly assumed the structure of an annular tropical cyclone. On October 8, Sergio weakened to Category 1 status. On October 9, Sergio weakened into a tropical storm. On October 12, Sergio made landfall as a tropical storm on the Baja California Peninsula, and then northwestern Mexico, before degenerating into a remnant low. On the next day, Sergio's remnant low dissipated.

On October 10, Sergio's approach warranted the issuance of tropical storm watches and warnings along the western and eastern coasts of Baja California.

Meteorological history

Map plotting the track and the intensity of the storm, according to the Saffir–Simpson scale

Hurricane Sergio originated from an area of low pressure that the National Hurricane Center (NHC) first noted on September 25. At this time, the NHC expected the area of low pressure to form a few hundred miles south or southwest of the Gulf of Tehuantepec in a couple days.[1] On September 26 at 12:00 UTC, a broad area of low pressure formed a few hundred miles south-southeast of the southern coast of Mexico.[2] The NHC continued to track the disturbance for a couple more days as it moved west-northwest.[3] On September 29 at 15:30 UTC, the NHC issued an off cycle advisory stating that Tropical Storm Sergio had formed approximately 345 miles (555 km) south-southwest of Acapulco, Mexico.[4] At 21:00 UTC, the NHC discussed that Sergio was indeed a tropical storm, but without an inner wind core. Instead, the maximum sustained winds were located in a band approximately 110 nautical miles east of the center.[5]

Sergio continued to gradually intensify over the next couple of days, becoming a hurricane on October 2 at 03:00 UTC.[6] At this time, Sergio had a well defined eye underneath a deep convective overcast with cloud tops around -85° celsius.[7] Sergio then began a period of rapid intensification, becoming a major hurricane at 21:00 UTC.[8] Soon after, the intensification halted as northwesterly shear affected Sergio's inner core with microwave data indicating an open eyewall on the north side of the hurricane.[9] Sergio maintained its intensity for twelve hours before intensifying slightly.[10] At the same time, the mid-level ridge to the north had weakened, resulting in Sergio travelling to the northwest.[11] On October 4 at 03:00 UTC, Sergio became the eighth Category 4 hurricane of the season, breaking the old record of 7 which was set in 2015.[12] Six hours later, Sergio peaked with maximum sustained winds of 140 mph (220 km/h) and a minimum central pressure of 943 mbar (27.85 inHg).[13] Sergio maintained peak intensity for six hours before beginning a weakening trend.[14] At 03:00 UTC on October 5, it was noted that Sergio's structure had deteriorated with cloud tops warming and the eye becoming ragged and less distinct.[15] At 09:00 UTC, Sergio began to turn due to a mid-level ridge that was developing to the northwest. Over the next couple of days, Sergio turned from the northwest to the southwest.[16][17] At 15:00 UTC, Sergio bottomed out as a low-end Category 3 hurricane.[18]

A thunderstorm associated with the remnants of Sergio off the coast of Santa Monica, California, on October 12

Six hours later, Sergio began another period of intensification, reaching a secondary peak with winds of 125 mph (205 km/h) and a pressure of 951 mbar (28.09 inHg) on October 6 at 03:00 UTC. Twelve hours later, a shortwave trough weakened the ridge to the northwest, resulting in the commencement of another turn. Over the next few days, Sergio turned from the southwest to the northeast.[19][20] After maintaining secondary peak intensity for eighteen hours, Sergio weakened slightly due to upwelling at 03:00 UTC on October 7.[21] On October 7, after having weakened to a Category 2 hurricane, Sergio unexpectedly acquired the structure of an annular hurricane. At the same time, it was reported that the eye had doubled in size overnight.[22] At 03:00 UTC the next day, Sergio weakened to a Category 1 hurricane.[23] On October 9, at 21:00 UTC, Sergio weakened to a tropical storm, due to persistent unfavorable conditions.[24] Shortly after 12:00 UTC on October 12, Sergio made landfall in the Mulegé Municipality of Baja California Sur as a tropical storm, with winds of 45 mph (75 km/h).[25] Shortly after 18:00 UTC, Sergio made landfall in the state of Sonora and weakened to a tropical depression,[26] before degenerating into a remnant low by 21:00 UTC.[27] Early on October 13, Sergio's remnant low dissipated over northwestern Mexico.[28]

Preparations

On October 10, the Government of Mexico issued a tropical storm watch along the western coast of the Baja California Peninsula from Punta Eugenia to Cabo San Lazaro and along the eastern coast from Bahia San Juan Bautista to San Evaristo.[29] As Sergio rapidly approaching the peninsula, tropical storm watch in the west coast was upgraded to a tropical storm warning early on the next day.[30] The watches in the east coast was also upgraded to a tropical storm warning later on the same day.[31] All the watches and warnings were discounted as Sergio weakened moved inland.[26]

See also

References

  1. ↑ Zelinsky, David. NHC Graphical Outlook Archive. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 6 October 2018.
  2. ↑ Roberts, Dave. NHC Graphical Outlook Archive. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 6 October 2018.
  3. ↑ Stewart, Stacy. NHC Graphical Outlook Archive. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  4. ↑ Beven, Jack. Tropical Storm Sergio Special Advisory Number 1. National Hurricane Center (Report). Retrieved 7 October 2018.
  5. ↑ Beven, Jack. Tropical Storm Sergio Discussion Number 2. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  6. ↑ Beven, Jack. Hurricane Sergio Advisory Number 11. National Hurricane Center (Report). Retrieved 7 October 2018.
  7. ↑ Beven, Jack. Hurricane Sergio Discussion Number 11. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  8. ↑ Pasch, Richard. Hurricane Sergio Advisory Number 14. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  9. ↑ Blake, Eric. Hurricane Sergio Discussion Number 15. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  10. ↑ Pasch, Richard. Hurricane Sergio Advisory Number 17. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  11. ↑ Brown, Daniel. Hurricane Sergio Discussion Number 16. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  12. ↑ Blake, Eric. Hurricane Sergio Discussion Number 19. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  13. ↑ Berg, Robbie. Hurricane Sergio Advisory Number 20. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  14. ↑ Cangialosi, John. Hurricane Sergio Advisory Number 22. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  15. ↑ Brennan, Michael. Hurricane Sergio Discussion Number 23. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  16. ↑ Berg, Robbie. Hurricane Sergio Discussion Number 24. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  17. ↑ Stewart, Stacy. Hurricane Sergio Advisory Number 27. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  18. ↑ Roberts, Dave. Hurricane Sergio Advisory Number 25. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  19. ↑ Zelinsky, David. Hurricane Sergio Discussion Number 29. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  20. ↑ Roberts, Dave. Hurricane Sergio Advisory Number 40. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 10 October 2018.
  21. ↑ Stewart, Stacy. Hurricane Sergio Discussion Number 31. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 7 October 2018.
  22. ↑ Zelinsky, David. Hurricane Sergio Discussion Number 33. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 8 October 2018.
  23. ↑ Avila, Lixion. Hurricane Sergio Advisory Number 35. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 8 October 2018.
  24. ↑ Zelinsky, David. Tropical Storm Sergio Advisory Number 42. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 10 October 2018.
  25. ↑ Avila, Lixion. Tropical Storm Sergio Advisory Number 52A. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved October 14, 2018.
  26. 1 2 Lixion Avila (October 12, 2018). "Tropical Depression Sergio Intermediate Advisory Number 53A". Miami, Florida: National Hurricane Center. Retrieved October 14, 2018.
  27. ↑ Lixion Avila (October 12, 2018). "Remnants Of Sergio Advisory Number 54". National Hurricane Center. Retrieved October 14, 2018.
  28. ↑ "WPC Surface Analysis for 10/13/2018 at 06 UTC". Weather Prediction Center. October 13, 2018. Retrieved October 14, 2018.
  29. ↑ Roberts, Dave. Tropical Storm Sergio Advisory Number 44. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 10 October 2018.
  30. ↑ Roberts, Dave. Tropical Storm Sergio Advisory Number 47. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 14 October 2018.
  31. ↑ Avila, Lixion. Tropical Storm Sergio Advisory Number 49. National Hurricane Center (Report). National Oceanic and Atmospheric Administration. Retrieved 14 October 2018.

 This article incorporates public domain material from websites or documents of the National Weather Service.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.