Tropical Storm Karina (2008)

Infobox Hurricane
Name=Tropical Storm Karina
Type=Tropical Storm
Year=2008
Basin=EPac
Image location=Karina 2 September 2008 1815Z.jpg


Formed=September 2, 2008
Dissipated=September 3, 2008
1-min winds=35
Pressure=1000
Da

Fatalities=None
Areas=No land areas
Hurricane season=2008 Pacific hurricane season

Tropical Storm Karina was one of the shortest lived tropical cyclones to form in the Eastern Pacific basin and the shortest lived storm in the 2008 Pacific hurricane season. Karina was designated a tropical storm for only eleven hours before being downgraded to a tropical depression. Karina was the twelfth tropical cyclone and eleventh named storm of the season. The storm formed out of an area of low pressure located off the western coast of Mexico on the morning of September 1. The low quickly developed into a tropical storm the next morning at which time it was named Karina and reached its peak intensity of 40 mph (65 km/h) 1000 mbar (hPa; 29.54 inHg). Karina was downgraded to a tropical depression later that day as convection was blown away by strong wind shear. The depression later degenerated into a remnant low-pressure area on the afternoon of September 3. The low was last noted on September 5, while located 335 mi (540 km) southwest of the southern tip of Baja California Sur.

Meteorological history

The area of low pressure that formed into Tropical Storm Karina was first noted on the morning of September 1. The low was located under an area of moderate convection but was nearing cooler waters and a moist, but stable, air mass. [cite web|author=Wally Barnes|title=Tropical Weather Discussion 1605 UTC September 1, 2008|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Pac-Dis/2008090115.AXPZ20] By the late night hours, a low pressure center developed underneath deep convection associated with the storm. The storm was located in an area favorable for development but was nearing a hostile environment and cooler waters. In response to the newly formed low pressure, a tropical cyclone formation alert was issued due to the possibility of a tropical cyclone forming within 48 hours. However, strong upper-level easterly wind shear would limit development, if any were to occur. [cite web|author=Aguirre|title=Tropical Weather Discussion 0405 UTC September 2, 2008|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Pac-Dis/2008090203.AXPZ20] The next morning, wind shear was forecast to lessen somewhat within 48 hours, allowing a small window of opportunity for development. Convection associated with the storm was confined within 175 mi (280 km) of the center in the western semi-circle. The center of the storm was determined to be just to the east of the deep convection, due to the wind shear. [cite web|author=Cobb|title=Tropical Weather Discussion 1005 UTC September 2, 2008|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Pac-Dis/2008090209.AXPZ20] The low became better organized later in the morning. It was initially thought that the center was still dislocated from the deepest convection, but was determined to be underneath it, and the storm was subsequently declared Tropical Storm Karina shortly after at 9 a.m. (PST).cite web|author=Franklin|title=Tropical Storm Karina Special Discussion One|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=http://www.nhc.noaa.gov/archive/2008/ep12/ep122008.discus.001.shtml?] At the time of the upgrade, Karina was 265 mi (425 km) south-southwest of the southernmost tip of Baja California Sur.cite web|author=Franklin|title=Tropical Storm Karina Special Public Advisory One|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=http://www.nhc.noaa.gov/archive/2008/ep12/ep122008.public.001.shtml?]

Karina was located to the south of a weakening mid-level ridge, leading to a relatively slow west-northwest movement at 9 mph (15 km/h). Karina had winds of 40 mph (65 km/h) upon being named, which was its peak intensity. There was uncertainty in the intensity of the storm as the Dvorak technique—a system used to estimate the intensity of a tropical cyclone—rendered a T3.0, which corresponds to an intensity of 50 mph (80 km/h) but since the center of the storm had just moved under the deep convection, the winds were held at minimal tropical storm intensity. In the afternoon, most forecast models were in agreement on the future track and intensity of Karina. They were showing the storm quickly weakening to a tropical depression and meandering to the southwest of Baja California Sur in the low-level flow. [cite web|author=Franklin|title=Tropical Storm Karina Discussion Two|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=http://www.nhc.noaa.gov/archive/2008/ep12/ep122008.discus.002.shtml?] That night, only eleven hours after being declared a tropical storm, Karina was downgraded to a tropical depression.cite web|author=Blake|title=Tropical Depression Karina Discussion Three|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=http://www.nhc.noaa.gov/archive/2008/ep12/ep122008.discus.003.shtml?] Strong easterly wind shear of at least 25 mph (40 km/h) tore away the deep convection that previously surrounded Karina. [cite web|author=Kimberlain|title=Tropical Weather Discussion 0405 UTC September 3, 2008|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Pac-Dis/2008090303.AXPZ20] Karina was moving into a stable environment over cooling waters which would prevent convection from redeveloping, despite a forecast of lessening wind shear. The foreword motion also slowed down slightly to 7 mph (11 km/h). By the morning of September 3, convection had been blown 125 mi (200 km) from the center of Karina, leaving only a swirl of clouds. [cite web|author=Roberts/Pasch|title=Tropical Depression Karina Discussion Four|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=http://www.nhc.noaa.gov/archive/2008/ep12/ep122008.discus.004.shtml?] Karina degenerated into a remnant low-pressure area later that morning. The foreword speed continued to slowly lessen and the remnant low was drifting to the northwest at 5 mph (8 km/h). Since Karina had degenerated into a remnant low, the National Hurricane Center issued their fifth and final advisory on the storm. [cite web|author=Rhome|title=Remnant Low Karina Discussion Five|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=http://www.nhc.noaa.gov/archive/2008/ep12/ep122008.discus.005.shtml?] The remnant low meandered to the southwest of Baja California Sur for the next two days before dropping out of Tropical Weather Discussions on September 5. [cite web|author=Kimberlain/Berg|title=Tropical Weather Discussion 0405 UTC September 5, 2008|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Pac-Dis/2008090503.AXPZ20] [cite web|author=Clark Schauer|title=Tropical Weather Discussion 1005 UTC September 5, 2008|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Pac-Dis/2008090309.AXPZ20]

Impact, naming, and statistics

Karina remained over open waters for the duration of its existence. No ships reported sustained tropical storm-force winds.

When the area of low pressure was upgraded to Tropical Storm Karina on September 2, it was the first use of the name "Karina" for a tropical cyclone. It was used to replace "Kenna" which was retired in 2002 Pacific hurricane season due to the storm's impact in Mexico. [cite web|author=James L. Franklin|title=Hurricane Kenna (2002) Tropical Cyclone Report|year=2002|publisher=National Hurricane Center|accessdate=2008-10-05|url=http://www.nhc.noaa.gov/2002kenna.shtml] [cite web|author=NHC|title=Eastern Pacific Best Tracks, 1949-2007|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=http://www.nhc.noaa.gov/tracks1949to2007_epa.txt]

Since Karina was a short lived storm, it produced an Accumulated Cyclone Energy (ACE) of 0.1225. This value—an approximation of the kinetic energy used by a tropical system throughout its existence—is, so far, the lowest of the season. However, it is possible that Karina never reached tropical storm status as it is not noted in the season summary supplied by the National Climatic Data Center. [cite web|author=National Climatic Data Center|title=2008 Eastern North Pacific Ocean Tropical Cyclones|year=2008|publisher=NCDC|accessdate=2008-10-05|url=http://www.ncdc.noaa.gov/oa/climate/research/2008/2008-ne-pacific-trop-cyclones.html] The brevity of the storm was mirrored in the month of September as a whole. It was one of only two storms to form in the month, the other being Tropical Storm Lowell. Since there were only two storms in September for 2008, it was the least active September on record for the Eastern Pacific basin, using Accumulated Cyclone Energy as a measure. [cite web|author=Hurricane Specialists Unit|title=September 2008 Monthly Summary for the Eastern Pacific|year=2008|publisher=National Hurricane Center|accessdate=2008-10-05|url=http://www.nhc.noaa.gov/archive/2008/tws/MIATWSEP_sep.shtml?]

ee also

*2008 Pacific hurricane season
*

References

External links

* [http://www.nhc.noaa.gov/archive/2008/KARINA.shtml The NHC's archive] on Tropical Storm Karina.
* [http://www.nhc.noaa.gov/gtwo_epac.shtml The NHC's Tropical Cyclone Outlook] for the Eastern Pacific.