Hurricane Cosme (2007)

Infobox Hurricane
Name=Hurricane Cosme
Type=Hurricane
Year=2007
Basin=EPac
Image location=Cosme_16_july_2007_1945Z.jpg


Formed=July 14, 2007
Dissipated=July 23, 2007
1-min winds=65
Pressure=987
Da

Fatalities=None reported
Areas=Hawaii
Hurricane season=2007 Pacific hurricane season

Hurricane Cosme was a minimal hurricane that threatened Hawaii in mid-July 2007. The sixth tropical cyclone, third named storm and first hurricane of the 2007 Pacific hurricane season, Cosme originated from a tropical wave that emerged off the coast of Africa on June 27 and tracked westward before emerging in the eastern Pacific. The wave organized, and was classified as a tropical depression on July 14, a tropical storm on July 15, and a hurricane on July 16. Cosme reached peak intensity as a Category 1 hurricane, but quickly weakened due to cooler waters. Steadily decreasing in strength, the storm was downgraded to a tropical depression before passing to the south of the Hawaiian Islands. The depression crossed into the Central Pacific and degenerated into a remnant low by July 23. Because Cosme stayed far from land, effects were mostly minor. Swells up to convert|9|ft|m|abbr=on|lk=on and up to Convert|6.94|in|mm|abbr=on|lk=on of rainfall were reported, in addition to wind gusts of convert|40|mph|km/h|abbr=on|lk=on. No fatalities or injuries were reported, and only minimal damage occurred.

Meteorological history

The origins of Cosme can be traced back to a tropical wave that left the coast of Africa on June 27, 2007. Due to a lack of associated convection, the wave was difficult to track across the Atlantic Ocean and Caribbean Sea. It is estimated that the wave emerged into the Pacific Ocean on July 8. Because the system was embedded within the Intertropical Convergence Zone (ITCZ), development was initially slow. However, when it separated from the ITCZ on July 13, it increased in convective organization, and was classified as Tropical Depression Six-E about midway between Mexico and Hawaii.Cite web|author=Michelle Mainelli|title=Hurricane Cosme Tropical Cyclone Report|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/pdf/TCR-EP062007_Cosme.pdf] It tracked westward at convert|12|mph|km/h|abbr=on|lk=on under the steering currents of a deep tropical easterly flow. Although wind shear was generally light, ocean temperatures were only marginal for tropical cyclone intensification.Cite web|author=Avila|title=Tropical Depression Six-E Discussion Number 1|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.001.shtml?] [cite web|author=Avila|title=Tropical Depression Six-E Discussion Number 2|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.002.shtml?] Forecasters experienced difficulty in locating the exact center of circulation. By July 14, convection had steadily decreased, [cite web|author=Franklin|title=Tropical Depression Six-E Discussion Number 3|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.003.shtml?] although the storm's movement was initially uncertain due to its location within a broad low pressure area. [cite web|author=Avila|title=Tropical Depression Six-E Discussion Number 4|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.004.shtml?] Early on July 15 the overall cloud pattern improved, [Cite web|author=Mainelle|title=Tropical Depression Six-E Discussion Number 5|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.005.shtml?] and at 1800 UTC it was upgraded to Tropical Storm Cosme.

Shortly after attaining tropical storm status, the formerly broad circulation consolidated as banding features developed. [Cite web|author=Mainelle|title=Tropical Storm Cosme Discussion Number 6|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.006.shtml?] The inner core gradually condensed and tightened, as indicated by an AMSR-E overpass. [cite web|author=Beven|title=Tropical Storm Cosme Discussion Number 7|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.007.shtml?] On July 16 an eye began to form and Cosme intensified to attain winds of convert|65|mph|km/h|abbr=on|lk=on. Tracking northwest towards a weakness in the mid-level ridge, [cite web|author=Brown|title=Tropical Storm Cosme Discussion Number 8|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.008.shtml?] the cyclone continued to intensify and was upgraded to Hurricane Cosme late on July 16, about convert|1600|mi|km|abbr=on east of Hilo, Hawaii. The hurricane reached peak intensity with winds of convert|75|mph|km/h|abbr=on, although due to cooler waters it quickly weakened to a tropical storm, as the eye became ragged and cloud-filled. [cite web|author=Beven|title=Hurricane Cosme Discussion Number 11|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.011.shtml?]

By July 17, the cloud pattern had deteriorated, and its winds decreased to convert|46|mph|km/h|abbr=on. [Cite web|author=Mainelle|title=Tropical Storm Cosme Discussion Number 13|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.013.shtml?] The center subsequently became exposed, with just a few thunderstorms confined to the southwest portion of the storm as it began to accelerate to the west. [Cite web|author=Mainelle|title=Tropical Storm Cosme Discussion Number 14|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.014.shtml?] As easterly vertical wind shear increased, convection temporarily reformed in a concentrated area southwest of the center. [Cite web|author=Beven|title=Tropical Storm Cosme Discussion Number 15|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.015.shtml?] As Cosme reached steadily cooler water temperatures, it was downgraded to a tropical depression late on July 18 about convert|900|mi|km|abbr=on southeast of Hilo, Hawaii; at around the same time, the storm entered the forecast responsibility of the Central Pacific Hurricane Center. Tracking westward at convert|14|mph|km/h|abbr=on, maximum sustained winds were convert|35|mph|km/h|abbr=on with localized higher gusts. [Cite web|author=Burke|title=Tropical Depression Cosme Advisory Number 19|year=2007|publisher=Central Pacific Hurricane Center|accessdate=2008-04-15|url=http://www.prh.noaa.gov/cphc/tcpages/archive/2007/TCPCP1.EP062007.19.0707190313] Gradually weakening, Tropical Depression Cosme passed south of the Hawaiian islands on July 20 with a minimum central pressure of 1010 mbar.Cite web|author=Ballard|title=Tropical Depression Cosme Advisory Number 27|year=2007|publisher=Central Pacific Hurricane Center|accessdate=2008-04-15|url=http://www.prh.noaa.gov/cphc/tcpages/archive/2007/TCPCP1.EP062007.27.0707210244] On July 22, the depression came within convert|180|mi|km|abbr=on of Johnston Island, [Cite web|author=Houston|title=Tropical Depression Cosme Discussion Number 33|year=2007|publisher=Central Pacific Hurricane Center|accessdate=2008-04-15|url=http://www.prh.noaa.gov/cphc/tcpages/archive/2007/TCPCP1.EP062007.33.0707221445] and later that day, it degenerated into a remnant low.

Preparations and impact

Initially, Cosme was predicted to make landfall on Hawaii as a tropical storm. [Cite web|author=Franklin|title=Tropical Storm Cosme Discussion Number 12|year=2007|publisher=National Hurricane Center|accessdate=2008-04-15|url=http://www.nhc.noaa.gov/archive/2007/ep06/ep062007.discus.012.shtml?] In anticipation of the storm, the National Weather Service issued a flash flood watch for the island of Hawaii on July 20. Also, small craft advisories were in effect for Maui and Hawaii; [cite web|author=CBS News|title=Hawaii Braces For A Tropical Depression|year=2007|publisher=|accessdate=2008-04-15|url=http://www.cbsnews.com/stories/2007/07/20/storm/main3080068.shtml] wind advisories were issued for summits in those regions. [cite web|author=Mark Niesse|title=Tropical Depression Nears Hawaii|year=2007|publisher=San Francisco Chronicle|accessdate=2008-04-15|url=http://www.sfgate.com/cgi-bin/article.cgi?f=/n/a/2007/07/20/national/a174453D60.DTL] High surf advisories were also put into effect for coastal areas.Cite web|author=Jan TenBruggencate|title=Tropical depression dumps heavy rain on Hawaii|year=2007|publisher=USA Today|accessdate=2008-04-15|url=http://www.usatoday.com/weather/hurricane/2007-07-20-cosme-hawaii_N.htm] The Hawaii County Civil Defense prepared for the storm by planning for increases in emergency response personnel and opening of evacuation centers. [Cite web|author=Laurie Au|title=Storm set to weaken but could pose threat|year=2007|publisher=Honolulu Star-Bulletin|accessdate=2008-04-15|url=http://starbulletin.com/2007/07/17/news/story01.html] County crews worked to clean out drains and culverts to prevent flooding.

Because the depression stayed far from land, the effects were mostly minor and little damage was reported. A strong trade wind swell north of Cosme generated waves up to convert|9|ft|m|abbr=on high. [Cite web|author=National Climatic Data Center|title=Event report for Tropcal Depression Cosme|year=2007|publisher=|accessdate=2008-04-15|url=http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwevent~ShowEvent~672785] Rain bands produced up to Convert|6.94|in|mm|abbr=on|lk=on of rainfall, [Cite web|author=Kevin R. Kodama|title=July 2007 Precipitation Summary|year=2007|publisher=National Weather Service|accessdate=2008-04-15|url=http://www.prh.noaa.gov/hnl/hydro/pages/jul07sum.php] causing small stream and drainage ditch flooding, as well as ponding on roadways in portions of Hilo, Puna, and Kau. [Cite web|author=National Climatic Data Center|title=Event report for Tropical Depression Cosme (2)|year=2007|publisher=|accessdate=2008-04-15|url=http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwevent~ShowEvent~675287] The rainfall helped to relieve a persistent drought which had existed for several months.cite web|author=Associated Press|title=Tropical depression causes few problems in Hawaii|year=2007|publisher=USA Today|accessdate=2008-04-15|url=http://www.usatoday.com/weather/hurricane/2007-07-22-cosme_N.htm] Wind gusts reached convert|40|mph|km/h|abbr=on in southern portions of Hawaii, causing no known damage. Because the damage from the storm was minimal, the name "Cosme" was not retired and is included on the list of names for the 2013 Pacific hurricane season.

ee also

*List of Hawaii hurricanes
*Other tropical cyclones named Cosme

References