Tropical Storm Patricia (2009)

Tropical Storm Patricia was a short-lived tropical cyclone that briefly affected parts of Baja California Sur before rapidly degenerating over water. Developing from a tropical wave that traversed the Atlantic Ocean during September 2009, Patricia was first classified as a tropical depression on October 11 several hundred miles south of the Baja California Peninsula. The system quickly intensified into a tropical storm as it tracked in a general northward direction. By October 12, Patricia attained its peak intensity with winds of 60 mph (95 km/h) and a minimum barometric pressure of 996 mbar (hPa; 29.41 inHg). The following day, increasing wind shear and unfavorable conditions caused the storm to rapidly weaken. By the morning of October 14, Patricia had degenerated into a non-convective remnant low near the southern coastline of Baja California Sur. The remnants of the storm persisted until October 15, at which time they dissipated over open waters.

Tropical Storm Patricia
Tropical Storm Patricia at peak intensity on October 13
Meteorological history
FormedOctober 11, 2009
Remnant lowOctober 14, 2009
DissipatedOctober 15, 2009
Tropical storm
1-minute sustained (SSHWS/NWS)
Highest winds60 mph (95 km/h)
Lowest pressure996 mbar (hPa); 29.41 inHg
Overall effects
FatalitiesNone reported
Areas affectedBaja California Sur, Sinaloa, Sonora and Chihuahua
IBTrACSEdit this at Wikidata

Part of the 2009 Pacific hurricane season

Although the center of Patricia did not impact land, the outer bands caused significant rainfall in portions of western Mexico. In Sonora, up to 240 mm (9.4 in) of rain fell, leading to significant flooding that left 600 people homeless. Other Mexican states received similar impact. Overall, the effects of Patricia were minor and resulted in no loss of life.

Meteorological history

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Map plotting the storm's track and intensity, according to the Saffir–Simpson scale
Map key
  Tropical depression (≤38 mph, ≤62 km/h)
  Tropical storm (39–73 mph, 63–118 km/h)
  Category 1 (74–95 mph, 119–153 km/h)
  Category 2 (96–110 mph, 154–177 km/h)
  Category 3 (111–129 mph, 178–208 km/h)
  Category 4 (130–156 mph, 209–251 km/h)
  Category 5 (≥157 mph, ≥252 km/h)
  Unknown
Storm type
  Extratropical cyclone, remnant low, tropical disturbance, or monsoon depression

Tropical Storm Patricia originated from a tropical wave that moved off the west coast of Africa on September 23. Two days later, Tropical Depression Eight developed from the wave over the eastern Atlantic Ocean.[1] The depression tracked northwestward,[2] while the wave continued a steady westward track. By October 6, the system crossed Central America and entered the eastern Pacific Ocean. Gradual development took place over the following several days with widespread, scattered convection consolidating around a developing area of low pressure. On October 11, a well-defined circulation had formed and the National Hurricane Center (NHC) estimated that it developed into a tropical depression roughly 405 mi (650 km) south-southeast of the southern tip of Baja California Sur.[1]

Several hours later, the system further strengthened into a tropical storm and was named Patricia.[1] The low-level circulation became embedded within very deep convection and further intensification was anticipated. Patricia tracked north-northwest in a region of low to moderate wind shear, under the steering currents of a strong ridge of high pressure to the east and a trough located northwest. Although over warm sea surface temperatures, relatively stable air aloft prevented substantial intensification.[3] By the late morning of October 12, the overall extent of cloud cover had increased but the center became less defined.[4] Later that day, Patricia attained its peak intensity as a moderately strong tropical storm with winds of 60 mph (95 km/h) and a minimum barometric pressure of 996 mbar (hPa; 29.41 inHg).[1]

The storm maintained this intensity for several hours as its central dense overcast remained intact despite increasing wind shear. However, the NHC stated that there was a 20% chance of the storm becoming a hurricane within 24 hours based on climatological factors and the average forecast intensity errors.[5] However, this did not take place. The combination of moderate wind shear and a stable environment caused Patricia to rapidly weaken on October 13.[1] The storm's cirrus outflow became weak in all directions and convection diminished.[6] Later that day, convective developed ceased to occur as the storm neared the south tip of Baja California Sur. Early on October 14, Patricia degenerated into a remnant low pressure area, bypassing tropical depression status, roughly 30 mi (50 km) south of the Baja California Peninsula. The remnant low turned westward and tracked over open waters before dissipating on October 15.[1]

Preparations and impact

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Several hours after Patricia was classified as a tropical storm on October 12, the National Hurricane Center issued a tropical storm watch for areas along Baja California Sur between La Paz and Santa Fe. The following day, the watch was upgraded to a tropical storm warning for areas between Buenavista and Agua Blanca. However, the storm's rapid decay on October 14 allowed the watches and warnings to be discontinued.[1] Officials in the threatened region began preparing by closing schools and opening 159 shelters on October 12. The Civil Protection Department was prepared to evacuate residents in low-lying area if necessary. Resorts and hotels cancelled all outdoor activities and brought all loose objects indoors.[7] The city of Los Cabos was placed under a state of emergency as flooding rains were forecast to impact the area.[8] Ports in the region were also shut down due to rough seas.[9]

The storm's quick deterioration led to significantly less impact than anticipated.[1] High waves affected the coastlines of Baja California Sur, Sinaloa and Nayarit.[10] Parts of Sinaloa also recorded heavy rainfall from Patricia, peaking at 184.5 mm (7.26 in) in Higuera de Zaragoza.[11] Subsequent flooding was reported in 12 municipalities in the state, resulting in the evacuation of 3,000 people. Officials also closed elementary schools throughout the affected area due to the anticipation of flood waters.[12] In southern Sonora, rainfall up to 240 mm (9.4 in)[13] led to widespread flooding. Officials reported that 181 people sought refuge in shelters. Additionally, relief agencies supplied 500 people with food during the storm.[14] A total of 2,272 hectares (5,614 acres) of agricultural land was inundated by flood waters. Roughly 815 people were left homeless in the wake of the storm, 600 of whom were in Sonora.[15][16]

See also

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References

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  1. ^ a b c d e f g h Christopher W. Landsea and Richard J. Pasch (November 10, 2009). "Tropical Storm Patricia Tropical Cyclone Report" (PDF). National Hurricane Center. Retrieved January 4, 2010.
  2. ^ Todd B. Kimberlain (October 23, 2009). "Tropical Depression Eight Tropical Cyclone Report" (PDF). National Hurricane Center. Retrieved January 5, 2010.
  3. ^ Chris Landsea and Richard Pasch (October 11, 2009). "Tropical Storm Patricia Discussion Two". National Hurricane Center. Retrieved January 6, 2010.
  4. ^ Todd Kimberlain (October 12, 2009). "Tropical Storm Patricia Discussion Four". National Hurricane Center. Retrieved January 6, 2010.
  5. ^ Chris Landsea and Richard Pasch (October 12, 2009). "Tropical Storm Patricia Discussion Six". National Hurricane Center. Retrieved January 6, 2010.
  6. ^ Jack Beven (October 13, 2009). "Tropical Storm Patricia Discussion Eight". National Hurricane Center. Retrieved January 6, 2010.
  7. ^ "Weakening Tropical Storm Patricia nears Mexico". The Mercury News. Associated Press. October 12, 2009. Retrieved January 4, 2010. [dead link]
  8. ^ "Pacific storm Rick strengthens to hurricane". The Inquirer. Associated Press. October 16, 2009. Archived from the original on October 19, 2009. Retrieved January 4, 2010.
  9. ^ "Pide BCS declaratoria de emergencia por 'Patricia'". El Siglo de Torreón (in Spanish). El Universal. October 12, 2009. Retrieved January 4, 2010.
  10. ^ "Afectará a tres estados la tormenta tropical "Patricia"". Editorial Noroeste (in Spanish). October 13, 2009. Archived from the original on July 22, 2011. Retrieved January 4, 2010.
  11. ^ Alberto Hdz.Unzón y MG Cirilo Bravo Lujano (2009). Reseña de la tormenta tropical "Patricia" (PDF) (Report) (in Spanish). Servicio Meteorológico Nacional. Archived from the original (PDF) on February 16, 2010. Retrieved January 4, 2010.
  12. ^ "Alerta en Sonora por lluvias de Patricia". El Universal (in Spanish). October 12, 2009. Retrieved January 4, 2010.
  13. ^ Sintesis Agropecuaria De Sonora (Report) (in Spanish). Sonora de la Secretaría de Agricultura. 2009. Archived from the original (PDF) on July 22, 2011. Retrieved January 4, 2010.
  14. ^ El Comité de Operaciones de Emergencia hizo un llamado a los habitantes del sur y de la sierra alta de Sonora a extremar precauciones y estar atentos al seguimiento de la tormenta tropical "Patricia" (Report) (in Spanish). Government of Sonora. October 13, 2009. Retrieved January 4, 2010.[permanent dead link]
  15. ^ "Destruye 'Patricia' 815 has. en agro". Noroeste (in Spanish). October 15, 2009. Archived from the original on August 19, 2011. Retrieved January 5, 2010.
  16. ^ "Patricia deja sin vivienda a 600 familias". La Jordana (in Spanish). October 15, 2009. Retrieved January 4, 2010.
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