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Map plotting the track and the intensity of the storm, according to the Saffir–Simpson scale [nb 1]

On October 1, a large area of disturbed weather formed over the central Caribbean Sea and absorbed the remnants of Tropical Storm Kirk. A convective burst on 2 October led to the formation of a surface low southwest of Jamaica on 3 October, and this system moved west-southwestward toward Honduras on October 4. By 5 October, the low became embedded within a cyclonic gyre over Central America, with a vorticity center to the southwest over the Eastern Pacific Ocean. On 6 October, the vorticity center situated over the Pacific moved inland over Central America, and became absorbed into the larger gyre, whose center reformed over the Caribbean Sea. [1] Aside from the moderate wind shear, the system was in favorable conditions, and the circulation as well as the convection associated with the low became better organized, and a tropical depression formed at 06:00 UTC on 7 October. [1] [2]

The center of the depression moved to the north-east as a result of strong convective bursts. After the movement, the system moved north-northeastward as it moved around the west side of a mid-level ridge over the western Atlantic. Despite moderate-to-strong southwesterly wind shear caused by an upper-level trough over the central Gulf of Mexico, rapid intensification (RI) took place, with the cyclone becoming a tropical storm 6 hours after its initial designation [3], and a hurricane a day later by 12:00 UTC on 8 October. [4] Michael attained 10-minute sustained wind speeds of 85 knots (98 mph; 157 km/h) as its center passed just west of Cabo del San Antonio, Cuba, near 18:30 on the same day. Michael attained a ragged eye, which cleared up and became uniform shortly after. [4] [5]

The eye of Hurricane Michael near peak intensity, seen from GOES-16 “Red” Visible (0.64 µm) imagery on October 10

Dry air northward of the system caused initial decay in the eyewall, and subsequent pausing of intensification occurred as it reached the southeastern Gulf of Mexico late on 8 October. The pause was temporary, and rapid intensification resumed by 12:00 UTC on October 9, and the hurricane turned north-northwestward that day under the influence of the aforementioned mid-level ridge. Michael moved northward on October 10 as it moved between the ridge and a mid-latitude shortwave trough moving through the western Gulf Coast states. This trough also created a strong outflow channel to the north, and the enhanced outflow aided the rapid intensification, which continued until landfall. Michael developed thick, strong convective bands which surrounded its uniform, clear eye. [4] Strong thunderstorms pulsed around the center as it continued to creep slowly toward the Gulf Coast. Before reaching the coast, Michael turned northeastward as it encountered mid-latitude westerlies. On 17:30 UTC, October 10, Michael made its first landfall near Tyndall Air Force Base in the Florida Panhandle, southeast of Panama City. By that time, Michael attained its peak intensity with a wind speed of 140 knots (161 mph; 259 km/h) and a central barometric pressure of 919 mbar (hPa; 27.14 inHg), classifying it as a category 5 hurricane, the strongest on the Saffir-Simpson hurricane wind scale (SSHWS). [4]

Michael rapidly weakened after landfall as it accelerated northeastward across the central Florida Panhandle, and the maximum winds dropped below the category 3 equivalent on the SSHWS scale before the eye moved into southwestern Georgia at around 21:30 on October 10. The center passed just west of Albany and then tracked just southeast of Macon shortly after the cyclone weakened to tropical storm-intensity. [6] Continuing northeastward, the center passed just west of Augusta before crossing into South Carolina at 11:00 UTC on October 11. By this time, the winds in the eye of the system had decreased below tropical-storm force. [6] Tropical-storm-force winds continued over the coast areas and coastal waters of Georgia ad South Carolina, and the storm center entered North Carolina by 15:00 UTC.

Michael went through an extratropical transition as it moved into North Carolina, with the central pressure falling and the winds intensifying to the west and northwest of an increasingly elongated center. The transition was completed by 00:00 UTC on October 12. While this occurred, Michael turned east-northeastward, with the center passing north of Raleigh, then moved across the Norfolk area and into the western Atlantic Ocean by 06:00 UTC on October 12. Accelerating east-northwestward along with the westerlies, the extratropical cyclone re-acquired hurricane-force winds as a result of baroclinic forcing on October 13, over the open ocean south of Nova Scotia and Newfoundland. A rapid eastward motion carried the system into the northeastern Atlantic the next day. Soon after, the low weakened while it turned southeastward and southward around the northeast side of the subtropical ridge, and the system dissipated late on October 15, just west of northern Portugal. [7]


Cite error: There are <ref group=nb> tags on this page, but the references will not show without a {{reflist|group=nb}} template (see the help page).

  1. ^ a b Jack Beven (6 Oct 2018). Potential Tropical Cyclone Fourteen Discussion Number 1 (Report). National Hurricane Center and Central Pacific Hurricane Center. Retrieved 8 July 2020. Cite error: The named reference "Potential Tropical Cyclone FOURTEEN" was defined multiple times with different content (see the help page).
  2. ^ Robbie Berg (7 Oct 2018). Tropical Depression Fourteen Discussion Number 3 (Report). National Hurricane Center and Central Pacific Hurricane Center. Retrieved 8 July 2020.
  3. ^ Daniel Brown (7 Oct 2018). Tropical Storm Michael Discussion Number 5 (Report). National Hurricane Center and Central Pacific Hurricane Center. Retrieved 8 July 2020.
  4. ^ a b c d Daniel Brown (8 Oct 2018). Hurricane Michael Discussion Number 8 (Report). National Hurricane Center and Central Pacific Hurricane Center. Retrieved 8 July 2020. Cite error: The named reference "Hurricane MICHAEL" was defined multiple times with different content (see the help page).
  5. ^ David Zelinsky (8 Oct 2018). NHC Tropical Weather Outlook - October 8, 2018 (Report). National Hurricane Center and Central Pacific Hurricane Center. Retrieved 8 July 2020.
  6. ^ a b Jack Beven (11 Oct 2018). Tropical Storm Michael Discussion Number 17 (Report). National Hurricane Center and Central Pacific Hurricane Center. Retrieved 8 July 2020. Cite error: The named reference "Tropical Storm MICHAEL" was defined multiple times with different content (see the help page).
  7. ^ Jack Beven (12 Oct 2018). Post-Tropical Cyclone Michael Discussion Number 23 (Report). National Hurricane Center and Central Pacific Hurricane Center. Retrieved 8 July 2020.