Updated 06 October 2010

Early SeptemberWildfire in Colorado destroys 166 residences read more September 4thTropical Storm Earl makes landfall in Nova Scotia read more Mid SeptemberSeasonal rains displace affect 145,000 people in Chad read more Mid SeptemberThree hurricanes churn simultaneoulsy in the North Atlantic read more SeptemberLow Arctic sea ice extent leads thousands of walruses to migrate to Alaska's Arctic Ocean coast read more September 16thTwo tornadoes rip through New York City read more September 19th–20th&ndash21stTyphoon Fanapi hits Taiwan and mainland China read more September 16th–23stMassive storm batters parts of Australia and New Zealand read more September 27th–30thTwo storms systems drench the U.S. East Coast read more

Drought conditions

Under hot, dry, and windy conditions, a major wildfire broke out in Fourmile Canyon near Boulder, Colorado on September 6th. According to the U.S. Drought Monitor, abnormally dry conditions were present across this portion of the state and temperatures on the 5th and 6th reached 93°F and 94°F (33.9°C and 34.4°C), respectively, in nearby Denver. The fire scorched an estimated 6,400 acres (2,560 hectares) of land and destroyed 166 homes, including those of nine volunteer firefighters battling the blaze. With respect to the number of residences, this was the most destructive fire in Colorado history. On the 12th, a second blaze broke out 40 miles to the north in Loveland, destroying two homes and charring about 710 acres (287 hectares). Combined, the two fires cost more than 10 million U.S. dollars to fight.

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Extreme Temperatures

In the midst of a late-summer heat wave, downtown Los Angeles, California experienced its all-time warmest day since record keeping began in 1877. According to the National Weather Service, a temperature of 113°F (45°C) was recorded on September 27th, breaking the previous record of 112°F (44.4°C) set on June 26th, 1990. It is possible that the temperature was even higher, but the thermometer stopped working shortly after the record was set. Nearby, Long Beach tied its all-time maximum temperature record of 111°F (43.9°C). These records are even more noteworthy because the very warm temperatures came on the heels of one of the coolest meteorological summers (June, July, and August) in Los Angeles' record-keeping history. The average daily temperature for this period at the Los Angeles International Airport was 65.4°F (18.6°C), second only to the lowest average temperature of 65.0°F (18.3°C) in 1948. The average high temperature for the meteorological summer was 70.3°F (21.3°C), the lowest on record for that location. Just days before the heatwave began, record low temperatures were still being recorded across the area. On September 17th, the University of California at Los Angeles reported a low temperature of 53°F (11.7°C), breaking the old record of 55°F (12.8°C) for that date, previously set in 1973. The hot weather was brought on by a strong ridge of high pressure that anchored itself over Southern California, pushing out an upper level trough that had settled along the west coast for the past few months and contributed to the unusual coolness.

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Heavy rainfall and flooding

In the midst of its rainy season, heavy downpours affected an estimated 145,000 people in the African nation of Chad, leaving almost 70,000 people displaced, according to the U.N. Office for the Coordination of Humanitarian Affairs. Twenty-four deaths were directly associated with flooding events and another 46 were attributed to a related cholera outbreak. In total, about 700 people were suffering from cholera. About 77,000 acres (31,500 hectares) of cropland were destroyed. Oxfam reported that floods cut off access to villages that were waiting for emergency food rations. Chad's rainy season lasts from June through September; however, this year the rains began earlier and were heavy since the onset.

Heavier-than-normal monsoon rains continued in South Asia in September. The rains triggered flooding and landslides in the mountainous northern India state of Uttarakhand that killed at least 60 people on September 17th–19th. Thousands more were forced to flee their homes. According to the India Meteorological Department, rainfall across the country was 22 percent above average for the period September 1st–15th. In neighboring Bangladesh, monsoon rains caused rivers to overflow their banks, destroying 99,000 acres (40,000 hectares) of cropland and causing 140,000 residents to leave their homes.

An unusually moist storm system associated with the remnants of Hurricane Karl dumped four to eight inches (100–200 mm) of rain in some parts of southwest Wisconsin, southern Minnesota, and southeast South Dakota on September 22nd–23rd. In Arcadia, Wisconsin, almost half of the town's population of 2,400 residents were displaced as three-foot floodwaters submerged the downtown area. In Zumbro Falls, Minnesota, 180 people were forced to evacuate their homes. According to the National Weather Service, many towns set records for their wettest September day, including Zumbro Falls (6.37 inches, 162 mm) in southeast Minnesota and Alma Dam (5.15 inches, 131 mm) in western Wisconsin.

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Severe Storms

A macroburst—a sudden intense storm that produces straight-line winds—tore through New York City on September 16th, according to the National Weather Service. The macroburst had winds that reached 125 mph (201 km/hr), stretched for eight miles and was up to five miles wide. Two tornadoes—one in Brooklyn with winds up to 80 mph (129 km/hr) and one in Queens with winds hitting 100 mph (162 km/hr)—touched down in the city in the midst of the severe weather outbreak. This brought the total number of tornadoes in New York City this year to three, including one this past July. Prior to 2010, only seven tornadoes had been recorded in the city since 1950. The National Weather Service said that the macroburst was more destructive than the tornadoes. One person was killed, tens of thousands were left without power, an estimated 3,000 trees were uprooted, and rail services were delayed.

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Tropical Cyclones

Tropical Storm Earl developed in the North Atlantic on August 25th and was later classified as a major hurricane, earning Category 4 status on the Saffir-Simpson Hurricane Wind Scale on August 31st and reaching its peak on September 2nd with maximum sustained winds of 145 mph (233 km/hr). This was the strongest Atlantic hurricane since 2007. The storm's path took Earl north-northeastward parallel to the eastern U.S. seaboard where it remained offshore. Earl weakened and eventually made landfall as a tropical storm on September 4th in Nova Scotia, Canada, where one person was killed.

Kompasu, the Japanese word for compass, developed into a tropical storm in the East China Sea on August 28th. On August 31st, the storm—now Typhoon Kompasu—with maximum sustained winds of 90 mph (145 km/hr), passed over Japan's southern island of Okinawa. The storm strengthened to Category 3 status with maximum sustained winds of 115 mph (185 km/hr) as it took aim at the Korean Peninsula. Before reaching land again, Kompasu weakened back to a tropical storm and struck Ganghwa Island, near the South Korean capital city of Seoul, on September 2nd. At least five people were killed by the storm in South Korea—reported to be the strongest to hit the Seoul area in 15 years. The North Korean state media reported that dozens of people were killed in that country by the storm, although no specific numbers were provided. Additionally, 3,300 homes were lost, 74,000 acres (30,000 hectares) of cropland were washed away, and roads and railways were destroyed.

Tropical Depression 11-E formed quickly in the Eastern Pacific over the Gulf of Tehuantepec on September 3rd. The storm made landfall the next day near Salina Cruz, Mexico, located in the southern tip of the country. However, Guatemala reportedly sustained the most damage, as torrential downpours from the storm's rain bands led to flooding and at least 15 landslides in the mountainous terrain along the Pan-American Highway and other areas. At least 45 people were killed and 40,000 lost their homes. Over 65 miles (100 km) of the Pan-American Highway was closed and many other roads were blocked due to the slides. A bridge that was replaced after initially being destroyed by Tropical Storm Agatha in May was once again destroyed by this storm, cutting the main route to the southwestern portion of the country.

Hermine developed in the southwestern Gulf of Mexico's Bay of Campeche on September 5th and rapidly intensified to a tropical storm in just 21 hours. Tropical Depression 11-E contributed to Hermine's development. The storm had maximum sustained winds of 65 mph (105 km/hr) before making landfall over northeastern Mexico near the Texas border on the 6th. Hermine's strength dissipated to tropical depression status over land although heavy rain continued to fall as the storm moved northward over Texas toward Oklahoma and Kansas. At least eight people were killed. According to preliminary reports from the National Weather Service, Camp Mabry—located within Austin city limits—received 7.04 inches (179 mm) of rain on the 7th, shattering its daily record of 3.11 inches (79 mm), previously set in 1923. Average for the month of September at Camp Mabry is 2.91 inches (74 mm). Local reports stated that the highest rainfall totals of about 14 inches (356 mm) were recorded in an area stretching from Mansfield Dam to Georgetown. Additionally, the storm spawned several tornadoes in northern Texas near Dallas and in southern Oklahoma. In Mexico, the combined effects of Tropical Depression 11-E and Tropical Storm Hermine impacted more than 900,000 people. The states of Veracruz, Oaxaca, and Tabasco were hardest hit. In Veracruz, more than 200,000 residents were forced to flee their homes. In Tabasco, about 500,000 acres (200,000 hectares) of cropland were submerged, affecting the livelihood of about 20,000 farmers. The president of Mexico said that rains during July and August in the region were three and a half times higher than average. The rainy season in Mexico typically lasts from May to November.

Following Hermine, three more hurricanes quickly developed in the North Atlantic hurricane basin. Hurricanes Igor and Julia, which formed on September 8th and 12th, respectively, became simultaneous Category 4 storms on the 15th—the first time this feat has occurred in the North Atlantic since 1926 and only the second known time since 1900. While both storms were churning in the open waters of the Atlantic, Hurricane Karl formed a few hundred miles east of the Yucatan Peninsula on September 14th. A Category 1 Igor brushed the tiny island of Bermuda on the 19th, bringing heavy rains and strong winds, and leaving structural damages but no casualties. The storm made its way northward to Newfoundland, Canada where it made landfall with tropical storm-force winds. More than 7.9 inches (200 mm) of rainfall was reported along with wind gusts reaching up to 90 mph (145 km/hr). The storm quickly dissipated over land, but flooded roads, knocked down trees and power lines, and left at least one person missing in its wake. Hurricane Julia never made landfall, but did receive the distinction of becoming the easternmost Category 4 hurricane on record in the North Atlantic. Of the three hurricanes, Karl did the most damage, making landfall on September 17th in Mexico's state of Veracruz as a Category 3 storm with 115 mph (185 km/hr) winds, bringing heavy rains to both Mexico and Texas. Fifteen people were reportedly killed by the storm in Mexico as oil rigs were evacuated and the country's nuclear power facility was shut down. According to the governor of Veracruz, at least 500,000 people in that state were affected by Karl. In Texas, moisture from the storm led to heavy downpours. Corpus Christi received 7.16 inches (182 mm) of rain on the 19th—a daily record—adding to the 2.61 inches (66 mm) received the previous day. Several rivers surpassed flood stage and one person was killed after their car was swept away by raging waters.

In the western Pacific tropical cyclone basin, Typhoon Fanapi roared ashore over southern Taiwan on September 19th. A Category 2 storm at impact, with maximum sustained winds of 101 mph (162 km/hr), Fanapi dumped copious amounts of rain, including 42.5 inches (1080 mm) in Majia, a rural township in Pingtung County. Two people were killed, more than 100 were injured, and thousands were evacuated from their homes as the first storm to directly strike Taiwan this year moved across the island and headed for southeastern China. Fanapi was the 11th and strongest typhoon to strike mainland China to date in 2010, making landfall on September 20th in Fujian Province. The storm wreaked havoc in this region and in neighboring Guangdong Province, where winds up to 137 mph (220 km/hr) were reported and the heaviest rain in a century fell, according to China's Xinhua news agency. Shuangyao township in Yangchun City—the hardest hit area—reportedly received 21 inches (530 mm) of rainfall in a 24-hour period. The torrential rains triggered flooding and landslides, killing at least 70 people in Guangdong and leaving 65 others unaccounted for, according to media outlets. About 98,000 residents in low-lying areas were evacuated as more than 4,200 homes were destroyed and 120,300 acres (48,700 hectares) of cropland were submerged. In total, the storm was estimated to have caused more than 360 million U.S. dollars in damages and direct economic losses.

Tropical Storm Matthew formed on September 23rd, making landfall the next day near the Honduras-Nicaragua border, where it quickly lost strength and then stalled over land. According to multiple media outlets, at least one person in El Salvador, seven people in Venezuela, 10 people in Colombia, and 32 people in the southern Mexico states of Chiapas and Oaxaca were killed due to the heavy rains and flooding that triggered several major landslides. The remnants of the storm produced very heavy rainfall, with 10 to 20 inches estimated locally, and 30 inches (760 mm) in isolated areas.

A disturbance that formed in the Caribbean Sea on September 25th gradually became more developed and intensified. Tropical Storm Nicole was named on the 29th, but lost its tropical storm status just six hours later, making it the shortest lived named storm of the 2010 North Atlantic hurricane season. However, the remnants from Nicole produced very heavy rain and wreaked havoc across Jamaica, where 11 people were killed and another 11 were missing due to flash flooding, as well as Cuba, the Cayman Islands, the Bahamas, and southern Florida. More than eight inches of rain was reported in parts of Jamaica. The remnants also contributed to record torrential rains along the eastern U.S. seaboard from the Carolinas to Maine.

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Extratropical Cyclones

On September 27th, much of eastern North Carolina and eastern South Carolina received torrential rainfall due to the combination of a frontal boundary and moist, tropical air carried northward from the Caribbean. The hardest hit city was Wilmington, North Carolina, which received 10.33 inches (262 mm) of rain, making it the second wettest day in the city's period of record, which dates back to 1871. September 15th, 1999 saw 13.38 inches (340 mm) when Hurricane Floyd affected the area. However, the rain continued to fall in Wilmington as the remnants of Tropical Storm Nicole stretched northward. On September 29th, the extratropical system dumped 7.37 inches (187 mm) of rain, in addition to 1.96 inches (50 mm) received the previous day, bringing Wilmington's three-day rainfall total to 19.66 inches (499 mm). This was the city's all-time wettest three-day period on record. On the 30th, nearby Jacksonville, North Carolina received 12 inches (305 mm) of rain—about 25 percent of its annual average—in a six-hour period. At least five people were killed due to the flooding effects from the storm. Interestingly, much of North Carolina, along with large portions of the Southeast, was experiencing moderate to severe drought and record high temperatures prior to these storm events. Wilmington reported its warmest ever meteorological summer (June, July, August) in its 137-year period of record, including record average high maximum, average high minimum, and average daily temperatures.

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Severe winter weather

Heavy snow and ice wreaked havoc in parts of Australia's southern state of Tasmania on September 16th during a dangerous and unusual (austral) spring snow storm. According to the Bureau of Meteorology, Tasmania's capital city of Hobart recorded its coldest September day in 25 years. The maximum temperature for the day reached 47°F (8.5°C), which was 12°F (6.7°C) below the September average. Wind gusts of 88 mph (141 km/hr) were recorded at Cape Bruny. More than 12,000 residents lost power. The storm also generated enormous waves off the coast, including an 18.4 meter wave off Cape Sorrell, a possible record for Australia. The storm—described as 'the size of Australia'—made its way across the Tasman Sea toward New Zealand, striking the country on the 17th. Hurricane-force winds of up to 80 mph (130 km/hr) were recorded in some areas, including New Zealand's capital city of Wellington. Blizzard conditions that included high winds, snow, rain, hail, and sleet, persisted in parts of South Otago and Southland on New Zealand's South Island for six days in the midst of lamb birthing season. It was feared that up to one million lambs perished due to the extremely wet, cold conditions. According to a local meteorologist, the polar jet stream, which typically lies south of the country rose over the South Island and lower North Island, bringing high winds, heavy snow, and cold temperatures.

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Polar Events and Sea Ice

On September 19th, measured sea ice extent in the Arctic reached its minimum for the year (1.78 million square miles, or 4.60 million square kilometers). The melt season led to the third-lowest September average extent since the satellite record began in 1979. The average extent for September of 1.89 million square miles (4.90 million kilometers) was 30.4 percent less than the 1979–2000 average. Only 2007 and 2008 saw lower sea ice extents. Regarding the total amount of Arctic sea ice, according to the University of Washington's Polar Science Center (using a model that has compared well with observations), sea ice volume for September reached an all-time monthly low in 2010. The reported volume of 1,000 cubic miles (4,000 cubic kilometers) was 70 percent below the 1979–2009 September average of 3,200 cubic miles (13,400 cubic kilometers). Sea ice volume accounts for sea ice extent as well as the thickness of ice beneath the ocean's surface. The 2010 Arctic melt season allowed for two sailing expeditions—one Russian and one Norwegian—to successfully navigate both the Northern Sea Route and the Northwest Passage in a single season, the first time this feat has occurred in modern history.

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Ecosystems Impacts

In late summer 2010, for the third time in four years (also 2007 and 2009), walruses came ashore in Alaska—just north of Point Lay on the state's Arctic Ocean coast. Each of the three years the animals have migrated to this area reflect years with record or near-record low levels of Arctic sea ice; mid-September is typically when lowest levels are recorded for the year, and this year saw the third-lowest Arctic sea ice extent (behind 2007 and 2008) in the satellite record, which began in 1979. (2009 ranked as the fourth lowest.) The lack of sea ice in the eastern Chukchi Sea drove the animals by the thousands to congregate in this region, an area 50 miles (80 kilometers) farther south than they were previously observed in 2007 and 2009. Scientists from the U.S. Geological Survey (USGS) estimated that 10,000–20,000 animals came ashore. The most pressing concern was that the adult females—who weigh about a ton—would stampede and crush the younger, smaller walruses. Typical congregation numbers are up to about 500 animals, as opposed to the more than 10,000 in this group.

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Citing This Report

NOAA National Centers for Environmental Information, Global Hazards for September 2010, published online October 2010, retrieved on April 23, 2024 from https://www.ncei.noaa.gov/access/monitoring/monthly-report/hazards/201009.