Tropical Storm Douglas (2008)

Infobox Hurricane
Name=Tropical Storm Douglas
Type=Tropical storm
Year=2008
Basin=EPac
Image location=Douglas 02 jul 2008 2105Z.jpg


Formed=July 1, 2008
Dissipated=July 4, 2008
1-min winds=35
Pressure=1003
Da

Fatalities=None
Areas=Colima, Jalisco, and Nayarit
Hurricane season=2008 Pacific hurricane season

Tropical Storm Douglas was the fourth named storm of the 2008 Pacific hurricane season. Douglas developed out of a tropical wave that formed off the African coast on June 19 and traversed the Atlantic Ocean. On June 27, the wave crossed Central America and entered the Pacific Ocean. On July 1, the storm developed into Tropical Depression Four-E while located 245 nmi (250 km) southwest of Manzanillo, Mexico as it traveled to the northwest. Despite being dislocated from most of the convection by strong wind shear, the depression gradually became better organized and on the afternoon July 2, the depression was upgraded to Tropical Storm Douglas. Upon the upgrade, Douglas reached its peak intensity of 40 mph (65 km) and minimum pressure of 1003 mbar (hPa; 29.63 inHg). Douglas weakened to a tropical depression overnight on July 3. The depression became devoid of convection shortly after and was further downgraded to a remnant low-pressure area on the morning of July 4 as it turned towards the west. The remnant low continued to weaken and completely dissipated on July 6.

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Meteorological history

A disorganized tropical wave exited the coast of Africa on June 19. The wave remained poorly organized as it traversed the Atlantic and entered the Pacific Ocean on June 27. On June 28, deep convection developed and a broad low-level circulation developed along the wave while located a few hundred miles south of the Gulf of Tehuantepec. The low traveled to the northwest and began to develop a well-defined circulation. The low was upgraded to a tropical depression early on July 1 while located 245 nmi (250 km) southwest of Manzanillo, Mexico.cite web|author=Lixion A. Avila|title=Tropical Storm Douglas Tropical Cyclone Report|year=2008|publisher=National Hurricane Center|accessdate=2008-09-17|url=http://www.nhc.noaa.gov/pdf/TCR-EP042008_Douglas.pdf] cite web|author=Beven|title=Tropical Depression Four-E Discussion Number One|year=2008|publisher=National Hurricane Center|accessdate=2008-09-17|url=http://www.nhc.noaa.gov/archive/2008/ep04/ep042008.discus.001.shtml?]

The center of the depression was elongated as it entered an area of strong northeasterly wind shear. The shear caused the low to become displaced to the north of the convection. Despite the shear, deep convection developed in developing bands in the south and western portions of the storm. [cite web|author=Pasch|title=Tropical Depression Four-E Discussion Number Two|year=2008|publisher=National Hurricane Center|accessdate=2008-09-17|url=http://www.nhc.noaa.gov/archive/2008/ep04/ep042008.discus.002.shtml?] The depression continued to become better organized and on July 2, it was upgraded to Tropical Storm Douglas. However, the center of circulation remained located to the northeast of the deepest convection.cite web|author=Brown|title=Tropical Storm Douglas Discussion Number Three|year=2008|publisher=National Hurricane Center|accessdate=2008-09-17|url=http://www.nhc.noaa.gov/archive/2008/ep04/ep042008.discus.003.shtml?] During the late morning hours, the cloud tops began to warm, signifying that the system was weakening. A microwave satellite overpass earlier in the day revealed that the storm still had a broad circulation. [cite web|author=Brown|title=Tropical Storm Douglas Discussion Number Four|year=2008|publisher=National Hurricane Center|accessdate=2008-09-17|url=http://www.nhc.noaa.gov/archive/2008/ep04/ep042008.discus.004.shtml?] The structure of Douglas continued to deteriorate throughout the day and was barely a tropical storm as satellite estimates put the intensity at 35 mph (55 km/h) to 40 mph (65 km/h). [cite web|author=Beven|title=Tropical Storm Douglas Discussion Number Five|year=2008|publisher=National Hurricane Center|accessdate=2008-09-17|url=http://www.nhc.noaa.gov/archive/2008/ep04/ep042008.discus.005.shtml?]

On the morning of July 3, wind shear dislocated the center of Douglas even further to the northeast of the deepest convection and the storm began to move over cooler waters. Forecasts showed a rapid degeneration into a remnant low as the storm moved closer to a more hostile environment. [cite web|author=Knabb|title=Tropical Storm Douglas Discussion Number Six|year=2008|publisher=National Hurricane Center|accessdate=2008-09-17|url=http://www.nhc.noaa.gov/archive/2008/ep04/ep042008.discus.006.shtml?] By the late morning, Douglas was downgraded to a tropical depression as all the deep convection associated with the system dissipated, leaving only mid- to low-level convection. [cite web|author=Avila|title=Tropical Depression Douglas Discussion Number Seven|year=2008|publisher=National Hurricane Center|accessdate=2008-09-17|url=http://www.nhc.noaa.gov/archive/2008/ep04/ep042008.discus.007.shtml?] However, in the post-season analysis, it was determined that Douglas had remained a tropical storm through the early afternoon, six hours later than the operational advisories. By the early afternoon, Douglas was devoid of almost all convection and was a swirl of clouds. [cite web|author=Avila|title=Tropical Depression Douglas Discussion Number Eight|year=2008|publisher=National Hurricane Center|accessdate=2008-09-17|url=http://www.nhc.noaa.gov/archive/2008/ep04/ep042008.discus.008.shtml?] Douglas degenerated into a remnant low early on the morning of July 4. The remnant low moved towards the west for two days before dissipating out over open waters due to the effects of cool waters and strong wind shear.

Impact

Due to the proximity to land, outer rain bands associated with Douglas produced tropical storm force winds in Manzanillo, Mexico. Minor flood damage was reported along the coastline in Colima, Jalisco, and Nayarit. [cite web|author=Oscar Gutierrez, Justin Miranda, and Edgar Avila Perez|title=Ocasiona tormenta tropical Douglas intensas lluvias|year=2008|publisher=El Universal|accessdate=2008-09-18|url=http://www.eluniversal.com.mx/notas/519652.html] On July 2, a ship located to the southwest of the center reported a sustained wind of 30 mph (50 km/h).

References

External links

* [http://www.nhc.noaa.gov National Hurricane Center Website]
* [http://www.nhc.noaa.gov/gtwo_epac.shtml National Hurricane Center's Eastern Pacific Tropical Weather Outlook]