Hurricane Olga (2001)

Infobox Hurricane
Name=Hurricane Olga
Type=hurricane
Year=2001
Basin=Atl
Image location=Hurricane Olga 27 nov 2001 1714Z.jpg


Formed=November 24, 2001
Dissipated=December 6, 2001
1-min winds=80
Pressure=973
Da

Inflated=
Fatalities=None
Areas=Bermuda, Bahamas, Cuba, Florida
Hurricane season=2001 Atlantic hurricane season

Hurricane Olga was a late season category 1 Atlantic hurricane that formed during the 2001 Atlantic hurricane season. The fifteenth named storm, ninth and final hurricane of the 2001 season, Olga formed as a subtropical cyclone on November 24 and meandered westward where it reached hurricane status on November 26. Olga’s winds peaked at 90 mph (150 km/h) before the storm turned southeastward and weakening back into a tropical storm. Olga then dissipated as a tropical cyclone on December 6 east of the Bahamas. Its damaging effects were limited to ships at sea. The cyclone's remnants produced heavy rainfall across the Bahamas and Florida.

Meteorological history

An extratropical low formed on November 22 between the Leeward Islands and Bermuda. The low strengthened and acquired characteristics of a subtropical cyclone on November 24.cite web|author=Lixion A. Avila|year=2001|title=NHC Report on Olga|publisher=NOAA|accessdate=2007-08-15|url=http://www.nhc.noaa.gov/2001olga.html] Embedded in a weak steering currentcite web|author=Lawrence|year=2001|title=NHC Discussion #1|publisher=NOAA|accessdate=2007-08-20|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.001.html] , the subtropical cyclone moved slowly northwest as the winds reached 60 mph. [cite web|author=Beven|year=2001|title=NHC Advisory #2|publisher=NOAA|accessdate=2007-08-20|url=http://www.nhc.noaa.gov/archive/2001/pub/al172001.public.002.html] By November 25 satellite imagery showed the structure of the storm becoming more tropical with the convection becoming more distinct at the center. Responding to a ridge of high pressure to the north, the storm moved westward.cite web|author=Stewart|year=2001|title=NHC Discussion #3|publisher=NOAA|accessdate=2007-08-24|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.003.html] On November 26, satellite data showed the convection continuing to organize around the center and prompted meteorologists at the National Hurricane Center to upgrade the system to tropical storm status and named it "Olga" from the 2001 list of hurricane names for the Atlantic basin.cite web|author=Beven|year=2001|title=Tropical Storm Olga Discussion #8|publisher=NOAA|accessdate=2007-08-28|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.008.html]

Tropical Storm Olga then moved northwest where satellite imagery showed the storm developing an eye. At 1200 UTC, Olga was upgraded to hurricane status by the National Hurricane Center. Despite sea surface temperatures of 73-75°F(23-24°C), [cite web|author=Pasch|year=2001|title=Hurricane Olga Discussion #10|publisher=NOAA|accessdate=2007-08-29|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.010.html] Olga’s winds continued to increase as the storm made a double loop in the central Atlantic Ocean. Olga’s winds peaked at 90 mph (150 km/h) and the barometric pressure dropped to 973 millibars (28.73 inches). After completing the second loop, the storm swung southwestward where it encountered increased amount of vertical wind shear on November 28. The wind shear caused the center of Olga to become disorganized resulting the storm to weaken back to a minimal Category 1 hurricane. [cite web|author=Pasch|year=2001|title=Hurricane Olga Discussion #18|publisher=NOAA|accessdate=2007-08-29|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.018.html] On November 29, Olga then weakened to a tropical storm as it continued southwestward. [cite web|author=Lawrence|year=2001|title=Tropical Storm Olga Discussion #19|publisher=NOAA|accessdate=2007-08-29|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.019.html] On November 30, increasing wind shear exposed much of the convection at the center [cite web|author=Lawrence|year=2001|title=Tropical Storm Olga Discussion #23|publisher=NOAA|accessdate=2007-08-30|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.023.html] causing storm to weaken to a tropical depression by 1200 UTC. By 4 pm (EST), the storm maintained convection at the center of the storm although the overall circulation was distorted by the wind shear. [cite web|author=Franklin|year=2001|title=Tropical Depression Olga Discussion #25|publisher=NOAA|accessdate=2007-08-31|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.025.html] By 0300 UTC, Quickscat and TRMM satellite data showed deep convection returned to the center of the storm as it moved into an area of weaker wind shear. At the same time, the ridge of high pressure to the north of Olga was beginning to weaken, which weakened steering near the cyclone causing it to slow down. [cite web|author=Pasch|year=2001|title=Tropical Depression Olga Discussion #26|publisher=NOAA|accessdate=2007-09-04|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.026.html] The following day, Olga continued to maintain convection in its eastern quadrant as it continued southwestward. [cite web|author=Beven|year=2001|title=Tropical Depression Olga Discussion #27|publisher=NOAA|accessdate=2007-09-04|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.027.html] On December 1, satellite imagery reveled that the deep convection had redeveloped at the center, prompting forecasters at the National Hurricane Center to upgrade Olga back to tropical storm status. [cite web|author=Stewart|year=2001|title=Tropical Storm Olga Discussion #30|publisher=NOAA|accessdate=2007-09-05|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.030.html] By that time, the storm turned northward as a result of the ridge of high pressure weakening to the north of the storm. [cite web|author=Franklin|year=2001|title=Tropical Storm Olga Discussion #31|publisher=NOAA|accessdate=2007-09-07|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.031.html] Olga then reached its second peak intensity of 50 mph (80 km/h) as the storm continued northward. As the storm headed north, it encountered increasing vertical wind shear caused by a trough moving off the eastern United States coast. [cite web|author=Pasch|year=2001|title=Tropical Storm Olga Discussion #34|publisher=NOAA|accessdate=2007-09-10|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.034.html]

The resulting wind shear caused by the incoming trough from the west had caused much of the deep convection to be removed from the center, which forced the storm to weaken back to tropical depression status for a second time. [cite web|author=Avila|year=2001|title=Tropical Depression Olga Discussion #38|publisher=NOAA|accessdate=2007-09-10|url=http://www.nhc.noaa.gov/archive/2001/dis/al172001.discus.038.html] In addition, the weakening storm made its second and final loop before it lost much of its circulation and deep convection. By December 5, the National Hurricane Center issued its final advisory on Olga as the storm dissipated 600 miles east of the Bahamas. The remnants of Olga then crossed the Bahamas and skirted northern Cuba before dissipating in the Gulf of Mexico.

Preparations, impact and naming

Forecasters at the National Hurricane Center began issuing advisories on Olga on November 24 anticipating that the storm would threaten shipping lanes in the Atlantic. [cite web|author=Lawrence|year=2001|title=Subtropical Storm 2 Advisory #1|publisher=NOAA|accessdate=2007-09-12|url=http://www.nhc.noaa.gov/archive/2001/pub/al172001.public.001.html] In Bermuda, the Bermuda Weather Service issued gale warnings and local marine warnings for boats and other small water craft. The approach of Olga also forced cancellation of the World Yacht regatta.cite web|author=The Royal Gazette|year=2002|title=Bermuda was affected by several Tropical Cyclones during the 2001 season.|accessdate=2007-09-17|url=http://www.theroyalgazette.com/siftology.royalgazette/Article/article.jsp?articleId=7d2620f3003002e&sectionId=49] As Olga reached hurricane strength, meteorologists at the National Hurricane Center forecast the storm to bring rough seas to Bermuda, East Coast of the United States, the Bahamas and the northern Caribbean.cite web|author=Franklin|year=2001|title=Hurricane Olga Advisory #11|publisher=NOAA|accessdate=2007-09-17|url=http://www.nhc.noaa.gov/archive/2001/pub/al172001.public.011.html]

Several ships and boats in the path of Olga reported seas 12 feet (3.7 meters) or higher. One boat the "Manana Tres" reported a barometric pressure of 989 millibars and sustained structural damage. In Bermuda, Olga brought winds of 35-45 mph (56-72 km/h) and waves 15-22 feet (3.7-6.7 meters) to the island for several days. Damage there if any was minimal. The remnants of Olga also produced heavy rainfall across the Bahamas, Cuba and south Florida.

This storm was the first to be named "Olga" for the Atlantic Basin. Olga was second name used in the Atlantic beginning with 'O' after Hurricane Opal in 1995. [cite web|author=Unknown|year=2007|title=History of Atlantic Hurricane Names|accessdate=2007-09-18|url=http://www.atwc.org/history.txt] The name Olga was not retired by the World Meteorological Organization [cite web|author=National Hurricane Center|year=2007|title=Worldwide Tropical Cyclone Names|publisher=NOAA|accessdate=2007-09-18|url=http://www.nhc.noaa.gov/aboutnames.shtml] and it was used again during the 2007 Atlantic hurricane season.

ee also

*tropical cyclone

References