Tropical Storm Olga (2007)

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Infobox Hurricane
Name=Tropical Storm Olga
Type=Tropical storm
Year=2007
Basin=Atl
Image location=Olgacolor.jpg


Formed=December 11, 2007
Dissipated=December 13, 2007
1-min winds=50
Pressure=1003
Da

Fatalities=40 direct
Areas=Puerto Rico, Hispaniola, central Florida
Hurricane season=2007 Atlantic hurricane season

Tropical Storm Olga was the fifteenth named storm of the 2007 Atlantic hurricane season. In the second week of December, after the official end of the hurricane season, a low developed east of the northernmost Lesser Antilles. It slowly acquired tropical characteristics, and late on December 10, the NHC declared it Subtropical Storm Olga while just north of Puerto Rico. It is the first post-season storm since Tropical Storm Zeta in the 2005 season, making the 2007 season one of the few with activity both before and after the official bounds of the hurricane season. Olga was only one of a few out of season landfalls, and was the deadliest post-season storm in the Atlantic Basin, with 40 deaths. The storm made landfall on December 11 on the eastern tip of the Dominican Republic. Later that evening, Olga transitioned into a tropical storm just after making landfall. Olga tracked over Hispaniola and emerged in the Caribbean Sea. Strong wind shear and dry air caused Olga to weaken into a remnant low early on December 13.

The storm impacted many areas affected by Tropical Storm Noel a month earlier. In Puerto Rico, moderate rainfall caused one death. 37 fatalities were confirmed in the Dominican Republic, including twenty deaths due to the release of floodgates at a dam in Santiago Province. Two deaths were also reported in Haiti.

Meteorological history

In the first week of December, a westward-moving upper-level low led to the formation of a broad surface trough well to the east of the northern Lesser Antilles. With a strong ridge to its northeast, the trough tracked slowly westward, producing scattered convection and some cyclonic turning.cite web|author=Gladys Rubio|year=2007|title=December 7 Tropical Weather Discussion|publisher=National Hurricane Center|accessdate=2007-12-11|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Atl-Dis/2007120717.AXNT20] On December 8 convection began to persist in association with the trough and an upper-level low. [cite web|author=Patricia Wallace|year=2007|title=December 8 Tropical Weather Discussion|publisher=National Hurricane Center|accessdate=2007-12-11|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Atl-Dis/2007120823.AXNT20] Early on December 9, officials at the Tropical Prediction Center began classifying the system using the Hebert-Poteat technique, [cite web|author=Mike Tichacek|year=2007|title=December 9 Tropical Weather Discussion|publisher=National Hurricane Center|accessdate=2007-12-11|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Atl-Dis/2007120906.AXNT20] and several tropical cyclone forecast models anticipated its development of tropical characteristics. [cite web|author=Mike Formosa|year=2007|title=December 9 Tropical Weather Discussion|publisher=National Hurricane Center|accessdate=2007-12-11|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Atl-Dis/2007120917.AXNT20] The system, which consisted of a sharp trough with an area of gale force winds to its north, continued westward through an area of moderately warm sea surface temperatures. [cite web|author=James Franklin|year=2007|title=December 9 Special Tropical Disturbance Statement|publisher=National Hurricane Center|accessdate=2007-12-11|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Disturbance/2007120921.WONT41] On December 10 a low-level circulation developed within the system, though its convection had become disorganized and well-removed from the center. [cite web|author=James Franklin|year=2007|title=December 10 Special Tropical Disturbance Statement|publisher=National Hurricane Center|accessdate=2007-12-12|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Disturbance/2007121015.WONT41] Southerly wind shear left the structure asymmetric,cite web|author=John Cangialosi|year=2007|title=December 10 Tropical Weather Discussion|publisher=National Hurricane Center|accessdate=2007-12-12|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Atl-Dis/2007121017.AXNT20] and convection steadily increased closer to the center. With an upper-level low situated just south of the center, the National Hurricane Center classified it as Subtropical Storm Olga at 0300 UTC on December 11 while located about 55 miles (85 km) east of San Juan, Puerto Rico.cite web|author=Beven|year=2007|title=Subtropical Storm Olga Discussion One|publisher=National Hurricane Center|accessdate=2007-12-12|url=http://www.nhc.noaa.gov/archive/2007/al17/al172007.discus.001.shtml?] Upon being classified as a subtropical cyclone, Olga maintained well-defined outflow, and located to the southeast of a strong ridge over the western Atlantic Ocean, the cyclone tracked west-southwestward. The storm strengthened slightly while paralleling the north coast of Puerto Rico,cite web|author=Knabb & Mainelli|year=2007|title=Subtropical Storm Olga Discussion Two|publisher=National Hurricane Center|accessdate=2007-12-12|url=http://www.nhc.noaa.gov/archive/2007/al17/al172007.discus.002.shtml?] and after an increase in convection near the center, Olga made landfall near Punta Cana, Dominican Republic at 1800 UTC on December 11.cite web|author=Franklin|year=2007|title=Subtropical Storm Olga Discussion Four|publisher=National Hurricane Center|accessdate=2007-12-12|url=http://www.nhc.noaa.gov/archive/2007/al17/al172007.discus.004.shtml?] A Hurricane Hunters flight into the storm reported a tighter wind gradient and peak winds of 60 mph (95 km/h), and at 0000 UTC on December 12 the National Hurricane Center reclassified Olga as a tropical cyclone while it was still inland.cite web|author=Avila|year=2007|title=Tropical Storm Olga Public Advisory Four-A|publisher=National Hurricane Center|accessdate=2007-12-12|url=http://www.nhc.noaa.gov/archive/2007/al17/al172007.public_a.004.shtml?] Convection rapidly weakened as the storm crossed central Hispaniola, and upon reaching the Caribbean Sea the system lacked the convection required for the classification of a tropical cyclone; rainbands well to its northeast maintained stronger winds, though the center became ill-defined with dry air and strong wind shear.cite web|author=Franklin & Mainelli|year=2007|title=Tropical Storm Olga Discussion Seven|publisher=National Hurricane Center|accessdate=2007-12-12|url=http://www.nhc.noaa.gov/archive/2007/al17/al172007.discus.007.shtml?] Late on December 12, convection increased slightly over the center, though by that time the cyclone weakened to tropical depression status.cite web|author=Franklin & Mainelli|year=2007|title=Tropical Storm Olga Discussion Eight|publisher=National Hurricane Center|accessdate=2007-12-12|url=http://www.nhc.noaa.gov/archive/2007/al17/al172007.discus.008.shtml?] As significant convection failed to persist, the National Hurricane Center discontinued advisories on Olga earlier on December 13 while located about 80 miles (130 km) northwest of Kingston.cite web|author=Avila|year=2007|title=Tropical Depression Olga Discussion Nine|publisher=National Hurricane Center|accessdate=2007-12-13|url=http://www.nhc.noaa.gov/archive/2007/al17/al172007.public.009.shtml?]

Its remnants continued west-northwestward with a clear low-level circulation, producing scattered thunderstorms over Cuba and the Cayman Islands with its moisture extending northward into southern Florida. [cite web|author=Gladys Rubio|year=2007|title=December 13 Tropical Weather Discussion|publisher=National Hurricane Center|accessdate=2007-12-13|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Atl-Dis/2007121323.AXNT20] A small cluster of deep convection developed just east of the center, and the low-level circulation remained well-defined as it approached the coast of the Yucatán Peninsula. [cite web|author=Gladys Rubio|year=2007|title=December 14 Tropical Weather Discussion|publisher=National Hurricane Center|accessdate=2007-12-13|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Atl-Dis/2007121423.AXNT20] The remnants of Olga turned northward into the Gulf of Mexico as a cold front approached the center from the northwest. [cite web|author=Mike Tichacek|year=2007|title=December 15 Tropical Weather Discussion|publisher=National Hurricane Center|accessdate=2007-12-13|url=ftp://ftp.met.fsu.edu/pub/weather/tropical/Atl-Dis/2007121518.AXNT20] Late on December 16 and early on December 17, the low intensified as it approached the west coast of Florida, with sustained winds of tropical storm force, and gusts to hurricane force, being reported at Clearwater Beach. Ultimately, the approaching cold front absorbed the low as it moved across the Florida peninsula. The cold front was associated with a powerful winter storm that affected much of Eastern America during that weekend and killed at least 25 across six US states and three Canadian provinces tapped Olga's moisture, drawing it northeastward mainly offshore the East Coast.

Preparations

On December 10, the Tropical Prediction Center issued a gale warning for waters north of the Lesser Antilles, Puerto Rico, and the Dominican Republic, in association with the precursor disturbance to Olga. Upon it being classified as a subtropical cyclone, the government of the Dominican Republic issued a tropical storm warning from Cabo Engaño along the north coast to its border with Haiti; a tropical storm watch was also issued along the southern coastline to near Santo Domingo. [cite web|author=Beven|year=2007|title=Subtropical Storm Olga Public Advisory One|accessdate=2007-12-12|url=http://www.nhc.noaa.gov/archive/2007/al17/al172007.public.001.shtml?] Because winds were well to the north of its center, a tropical storm warning was not issued for Puerto Rico. Prior to it moving ashore, the government of Haiti issued a tropical storm warning for its northern coastline, [cite web|author=Franklin & Brown|year=2007|title=Subtropical Storm Olga Public Advisory Three|accessdate=2007-12-12|url=http://www.nhc.noaa.gov/archive/2007/al17/al172007.public.003.shtml?] and later a tropical storm warning was issued for the Turks and Caicos Islands, as well as the southeastern Bahamas. [cite web|author=Franklin & Brown|year=2007|title=Subtropical Storm Olga Public Advisory Four|accessdate=2007-12-12|url=http://www.nhc.noaa.gov/archive/2007/al17/al172007.public.004.shtml?]

The San Juan National Weather Service office issued a flood watch for all of Puerto Rico, including the islands of Culebra and Vieques. Extended periods of heavy rainfall also resulted in flash flood warnings for portions across the island.cite web|author=Puerto Rico National Weather Service|year=2007|title=Watches, Warnings, and Advisories for Tropical Storm Olga in Puerto Rico|accessdate=2007-12-13|url=http://www.webcitation.org/5U1Ss8vdV] Ferry service between Fajardo and the islands of Culebra and Vieques was temporarily suspended during the passage of the storm. [cite news|author=Associated Press|date=2007-12-11|title=Domestic News by State/Province|accessdate=2007-12-13] In the Dominican Republic, officials opened shelters in 15 provinces, with citizens in low-lying areas recommended to stay elsewhere during the passage of the storm; [cite news|author=Michael Melia|date=2007-12-11|title=Subtropical Storm Olga spreads heavy rains across Puerto Rico|accessdate=2007-12-13|publisher=Associated Press] citizens in 22 communities were evacuated.cite news|author=Ramon Almanzar|date=2007-12-11|title=Subtropical Storm Olga forces evacuations in Dominican Republic|accessdate=2007-12-13|publisher=Associated Press]

Impact

The cyclone dropped light to moderate precipitation across Puerto Rico, peaking at 11.13 inches (283 mm) near Ponce.cite web|author=David Roth|year=2007|title=Rainfall Summary for Tropical Storm Olga|publisher=Hydrometeorological Prediction Center|accessdate=2007-12-20|url=http://www.hpc.ncep.noaa.gov/tropical/rain/olga2007.html] The rainfall increased levels along several rivers across the island, including the Arecibo Big River which was reported at several feet above flood stage. Its passage left about 79,000 people without power and 144,000 without water. In the northern portion of the island, the rainfall caused a mudslides that buried an automobile, which killed its driver. [cite news
author=Ramon Almanzar
date=2007-12-12
title="Tropical Storm Olga forces evacuations in Dominican Republic; one killed in Puerto Rico"
publisher=Associated Press
url=http://www.pr-inside.com/tropical-storm-olga-forces-evacuations-in-r344416.htm
accessdate=2007-12-13]

Heavy rainfall fell across the Dominican Republic, with isolated totals of 10 inches (250 mm) expected. The rainfall caused flooding along the Yaque del Norte River, and initially there appeared to be a threat that the Tavera Dam along the river would fail, potentially killing thousands in Santiago Province. Officials instead opted to open all six floodgates at 0400 UTC on December 12, which released about 1.6 million gallons (6.1 million liters) of water into the river every second. The deluge created a 66 foot (20 m) wave of water that caught many off guard due to the time of night and only about 15 minutes to prepare, according to eyewitnesses who criticized the decision; the flooding killed at least 35 peoplecite news
date=2007-12-15
title=40 dead in Caribbean tropical storm
publisher=Agence France-Press/News.com.au
accessdate=2007-12-16
url=http://www.news.com.au/story/0,23599,22928524-1702,00.html?from=public_rss] and left homes in seven towns flooded.cite news|author=Los Angeles Times|date=2007-12-13|title=Tropical storm leaves 14 dead|accessdate=2007-12-13] Two other deaths were reported elsewhere in the country, and more than 34,000 people fled their homes due to the storm; more than 7,500 houses were damaged.cite news|author=Associated Press|date=2007-12-15
title=Dominican officials say Tropical Storm Olga causes major crop losses|accessdate=2007-12-20] Damage in the country was estimated at $1.5 billion (2007 DOP, $45 million 2007 USD). [ [http://www.reliefweb.int/rw/rwb.nsf/db900sid/MUMA-7A48PY?OpenDocument Situation Reports: Caribbean: Tropical Storm Olga - Dec 2007, Dominican Republic: Tropical Storm Olga OCHA Situation Report No. 3 ] ] In neighboring Haiti, two deaths were reported in the northern portion of the country.cite news|author=Associated Press|date=2007-12-18|title=Dominican president orders probe into opening of dam during Tropical Storm Olga|accessdate=2007-12-20|url=http://www.signonsandiego.com/news/world/20071218-1002-dominican-olga.html] On December 11, a station in the Turks and Caicos Islands recorded sustained winds of 36 mph (58 km/h).

While still moving through the western Caribbean sea, heavy rains fell along a trough in its northeast quadrant beginning on December 14, with a total of 7.08 inches/179.8 mm falling at Nettles Island, Florida. The remnant low intensified due to occasional convection forming near and northeast of the center as it approached the Sunshine State. Clearwater Beach recorded a pressure as low as 1002 mb as well as sustained winds reaching 45 mph (72 km/h), with gusts to 78 mph (126 km/h) between 4 and 5 on the morning of December 16. As a cold front approached, the low pressure area became ill-defined and dissipated before reaching Florida's Space Coast.

Despite the death toll from Tropical Storm Olga, the name was not retired and is included on the list of names for the 2013 Atlantic hurricane season.

References