Meteorological history of Hurricane Dean

Barry Macokiner
Category 5 major hurricane (SSHWS/NWS)
A map showing the track of a tropical cyclone as represented by colored dots. Each dot represents the position of the hurricane at five-hour intervals, and each color represents a different intensity.
Track map of Hurricane Dean.
FormedAugust 13, 2007
DissipatedAugust 23, 2007
Highest winds1-minute sustained: 175 mph (280 km/h)
Lowest pressure905 mbar (hPa); 26.72 inHg
Areas affectedLesser Antilles, Puerto Rico, Hispaniola, Jamaica, Cuba, Cayman Islands, Nicaragua, Honduras, Belize, Guatemala, Mexico
Part of the 2007 Atlantic hurricane season
Part of a series on Hurricane Dean

The meteorological history of Hurricane Dean began in the second week of August 2007 when a vigorous tropical wave moved off the west coast of Africa into the North Atlantic ocean. Although the wave initially experienced strong easterly wind shear, it quickly moved into an environment better suited for tropical development and gained organization. On the morning of August 13, the National Hurricane Center recognized the system's organization and designated it Tropical Depression Four while it was still more than 1,500 mi (2,400 km) east of the Lesser Antilles.

A deep layered ridge to its north steered the system west as it moved rapidly towards the Caribbean and into warmer waters. On August 14 the depression gained strength and was upgraded to Tropical Storm Dean. By August 16, the storm had intensified further and attained hurricane status. Hurricane Dean continued to intensify as it tracked westward through the Lesser Antilles. Once in the Caribbean Sea, the storm rapidly intensified to a Category 5 hurricane on the Saffir-Simpson Hurricane Scale. Weakening slightly, it brushed the southern coast of Jamaica on August 19 as a Category 4 hurricane and continued towards the Yucatán Peninsula through even warmer waters. The favorable conditions of the western Caribbean Sea allowed the storm to intensify and it regained Category 5 status the next day before making landfall in southern Quintana Roo.

Hurricane Dean was one of two storms in the 2007 Atlantic hurricane season to make landfall as a Category 5 hurricane and was the seventh most intense Atlantic hurricane ever recorded, tied with Camille and Mitch. After its first landfall, Hurricane Dean crossed the Yucatán Peninsula and emerged, weakened, into the Bay of Campeche. It briefly restrengthened in the warm waters of the bay before making a second landfall in Veracruz. Dean progressed to the northwest, weakening into a remnant low which finally dissipated over the southwestern United States.

Formation

Satellite image of the Low that eventually became Hurricane Dean. Taken at 12:45 UTC on August 12, 2007

On August 11, 2007, a vigorous tropical wave moved off the west coast of Africa, producing disorganized showers and thunderstorms.[1][2] It encountered conditions favorable for gradual development, and on August 12 it gained organization and became a low.[3][3] Strong upper-level easterly winds slowed development,[4][5] but on August 13 the tropical wave gained enough organization that the National Hurricane Center designated it Tropical Depression Four. At this time it was centered about 520 mi (835 km) west-southwest of Cape Verde.[6]

The depression was already exhibiting persistent deep convection in the western portion of its circulation.[7] It moved quickly westward, south of a deep layered ridge,[8] escaping the easterly wind shear that had been slowing its development and moving over warmer waters.[9] At 1500 UTC on August 14, the depression was upgraded to Tropical Storm Dean[10] while still 1450 mi (2300 km) east of Barbados.[11] Even as its convection waned slightly that afternoon, its intensity grew,[12] and convection flared in the center that night. Dry air and cooler air inflow from the north slowed structural development; nevertheless, ragged bands began to form on August 15.[13] By mid-morning, a rough banding eye had formed,[14] and by the next morning a full eye developed.[11] The storm was upgraded to Hurricane Dean at 0900 UTC August 16,[15] 550 mi (890 km) east of Barbados.[11]

A strong ridge of high pressure continued to push the system west, towards the Caribbean Sea.[16] That afternoon, convective banding and increasing upper-level outflow strengthened the storm to a Category 2 hurricane on the Saffir-Simpson Hurricane Scale.[17] The eye disappeared briefly overnight, possibly as part of a diurnal fluctuation,[18] but returned by the morning of August 17.[19]

Gulf of Mexico and demise

Hurricane Dean emerged into the Bay of Campeche as a Category 1 hurricane on the afternoon of August 21. Its inner core was largely disrupted,[11] so although a ragged eye reformed over the warm waters of the bay,[20] the hurricane no longer had the structure to support its previous strength.[11][21] Nevertheless, the warm waters of the bay proved conducive for some development and the eye contracted overnight, indicating that the hurricane was regaining structure. With better structure came stronger winds of 100 mph (160 km/h), and the storm was re-categorized as a Category 2 hurricane.[11][22]

The storm's strengthening pattern continued until Hurricane Dean made its second and final landfall at 1630 UTC August 22 near Tecolutla, Veracruz, just east of Gutiérrez Zamora and about 40 mi (65 km) south-southeast of Tuxpan.[23] A weather station at Requetemu, San Luis Potosí, recorded 15.4 in (39 cm) of rainfall during the storm's second landfall.[11] Dean weakened rapidly, losing its low level circulation within hours and its mid-level circulation the next day as it encountered the Sierra Madre Oriental mountain range. Its remnants passed over the mountains and into the eastern Pacific Ocean as a broad area of low pressure.[24] Hurricane Dean's remnant low pressure system then drifted north into southern California, bringing thunderstorms to northern San Diego County, and more than 2 in (5 cm) of rain to Lake Wohlford. In Escondido almost 2 in (5 cm) of rain fell in 90 minutes.[25] The remnant low pressure system weakened over western Arizona and southern California before finally dissipating on August 30.[26]

See also

References

  1. ^ Richard Knabb (2007-08-11). "August 11 Tropical Weather Outlook 15z". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-14.
  2. ^ Jamie Rhome (2007-08-11). "August 11 Tropical Weather Outlook 21z". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-14.
  3. ^ a b Jamie Rhome (2007-08-12). "August 12 Tropical Weather Outlook 09z". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-14.
  4. ^ Daniel Brown, James Franklin (2007-08-12). "August 12 Tropical Weather Outlook 21z". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-14.
  5. ^ Daniel Brown (2007-08-12). "August 12 Tropical Weather Outlook 03z". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-14.
  6. ^ Richard Knabb, Eric Blake (2007-08-13). "August 13 Tropical Weather Outlook 15z". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-14.
  7. ^ Richard Knabb (2007-08-13). "Tropical Depression Four Discussion One". National Hurricane Center. Retrieved 2007-08-14.
  8. ^ Daniel Brown, James Franklin (2007-08-13). "Tropical Depression Four Discussion Three". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-14.
  9. ^ Jamie Rhome (2007-08-14). "Tropical Depression Four Discussion Four". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-14.
  10. ^ Lixion Avila (2007-08-15). "Tropical Storm Dean Discussion Five". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-14.
  11. ^ a b c d e f g Cite error: The named reference DeanTCR was invoked but never defined (see the help page).
  12. ^ Chris Landsea, Richard Knabb (2007-08-14). "Tropical Storm Dean Discussion Six". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-15.
  13. ^ Jack Beven (2007-08-15). "Tropical Storm Dean Discussion Eight". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-15.
  14. ^ Eric Blake (2007-08-15). "Tropical Storm Dean Discussion Nine". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-15.
  15. ^ Jack Beven (2007-08-16). "Hurricane Dean Discussion Twelve". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-16.
  16. ^ Eric Blake (2007-08-16). "Hurricane Dean Discussion Thirteen". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-16.
  17. ^ Lixion Avila, Eric Blake (2007-08-16). "Hurricane Dean Discussion Fourteen". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-16.
  18. ^ James Franklin (2007-08-16). "Hurricane Dean Discussion Fifteen". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-17.
  19. ^ Jack Beven (2007-08-17). "Hurricane Dean Discussion Sixteen". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-16.
  20. ^ Lixion Avila (2007-08-21). "Hurricane Dean Discussion Thirty Six". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-21.
  21. ^ Jack Beven (2007-08-22). "Hurricane Dean Discussion Thirty Seven". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-22.
  22. ^ James Franklin, Michelle Mainelli (2007-08-22). "Hurricane Dean Discussion Thirty Eight". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-22.
  23. ^ James Franklin (2007-08-22). "Hurricane Dean Tropical Cyclone Updatework=National Hurricane Center". National Oceanic and Atmospheric Administration. Retrieved 2007-08-22.
  24. ^ Lixion Avila (2007-08-22). "Hurricane Dean Discussion Forty". National Hurricane Center. National Oceanic and Atmospheric Administration. Retrieved 2007-08-22.
  25. ^ Stuart Hinson (2007-08-26). "NCDC Event Record Details 679276". National Climate Data Center. National Oceanic and Atmospheric Administration. Archived from the original on 2011-05-20. Retrieved 2008-07-02.
  26. ^ Jackson (2007-08-30). "Surface Weather Map at 7:00 A.M. E.S.T." National Centers for Environmental Prediction, Hydrometeorological Prediction Center. National Oceanic and Atmospheric Administration. Retrieved 2008-07-02.

External links