Hurricane Alma (1970)
Encyclopedia
Hurricane Alma was one of only four Atlantic tropical cyclones to reach hurricane status in May. It developed on May 17 north of Panama
, and rapidly intensified on May 20 to peak winds of 80 mph (128.7 km/h), near Jamaica
and the Cayman Islands
. It stalled south of Cuba
and deteriorated due to wind shear, and by May 22 it weakened to tropical depression status. After progressing northwestward and crossing western Cuba, Alma reorganized in the Gulf of Mexico
, although continued shear prevented strengthening. It moved across Florida
on May 25, and on May 27 it dissipated off the coast of Virginia
.
The storm first brought gusty winds and heavy rainfall to Jamaica and the Cayman Islands. While it was weakening, Alma produced flooding in central and eastern Cuba, causing seven deaths and forcing 3,000 people to evacuate. Moderate precipitation spread across Florida, while thunderstorms from the storm caused light damage and killed one girl. Moisture from the storm spread up the Atlantic coast.
, reported that a tropical depression had formed about 470 miles (756.4 km) to the southeast of Kingston
, Jamaica
. Over the next couple of days, the depression became better organized as it moved towards the northwest; on May 19 it entered an area of favorable environmental conditions, which enabled the depression to rapidly intensify. On May 20 it strengthened into a tropical storm, at which point it was given the name Alma. That day, it rapidly strengthened under favorable developmental conditions, which included low wind shear
, strong upper-level outflow
, and apparent eastward inflow
. Later on May 20, a Navy reconnaissance plane recorded winds of 80 mph (128.7 km/h), which proved to be the peak intensity of Alma. It became one of only four Atlantic hurricanes on record in the month of May.
Subsequent to its peak intensity, increasing westerly shear disrupted the storm's circulation and thermal pattern, which caused rapid weakening to tropical storm strength and later tropical depression status. By May 22, the low pressure area became poorly defined after stalling south of Cuba
; with only a few squalls and showers, advisories were discontinued on Alma. The remnants of Alma continued westward near the Cayman Islands, and later turned to the north, passing over western Cuba.
On May 24, the low pressure area reorganized as spiral rainbands became more evident on radar, and Alma was re-classified as a tropical depression. As the depression approached the Florida coast, radar imagery indicated the system remained well-organized, with a spiral band structure around an eye
feature; however, wind shear limited convection and strength, and Alma moved ashore as a depression near Cedar Key on May 25. It turned northeastward and moved across the southeastern United States, becoming extratropical in North Carolina
on May 27. After moving off the coast of Virginia, the remnants of Alma were absorbed by an approaching cold front
.
on May 21, where winds of up to 65 mph (104.6 km/h) were recorded. Gale force winds and heavy rainfall also occurred in Jamaica. Heavy rains ahead of the storm caused flash flooding in central and eastern Cuba. Seven people died as a result, and several homes were destroyed. The flooding forced the evacuation of 3,000 people in Oriente Province. Inclement weather closed 16 sugar mills, which stalled harvesting that was already behind schedule in the country.
In Florida, the remnants of Alma brought rainfall across most of the state, with some isolated areas experiencing 5 inches (12.7 cm) or more. The highest rainfall from the storm was near Miami, Florida
, with 6.66 inches (16.92 cm) of rain. The rainfall was beneficial in alleviating drought conditions, although thunderstorms caused hazardous driving conditions in the Florida Keys
and elsewhere in the state. Small craft warnings were posted along the coast. One girl died from lightning in Miami, and a thunderstorm near Fort Myers damaged some roofs and outbuildings. In Saint Petersburg, flooding disrupted phonelines in about 400 households. Merritt Island
experienced 45 mph (72.4 km/h) wind gusts. In Georgia
, South Carolina
, North Carolina
, Virginia
, and Maryland
, Alma dropped moderate rainfall, with some isolated areas receiving up to 3 inches (7.62 cm). Near Columbia, South Carolina
, the remnants of Alma spawned a tornado which destroyed a roof.
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
, and rapidly intensified on May 20 to peak winds of 80 mph (128.7 km/h), near Jamaica
Jamaica
Jamaica is an island nation of the Greater Antilles, in length, up to in width and 10,990 square kilometres in area. It is situated in the Caribbean Sea, about south of Cuba, and west of Hispaniola, the island harbouring the nation-states Haiti and the Dominican Republic...
and the Cayman Islands
Cayman Islands
The Cayman Islands is a British Overseas Territory and overseas territory of the European Union located in the western Caribbean Sea. The territory comprises the three islands of Grand Cayman, Cayman Brac, and Little Cayman, located south of Cuba and northwest of Jamaica...
. It stalled south of Cuba
Cuba
The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...
and deteriorated due to wind shear, and by May 22 it weakened to tropical depression status. After progressing northwestward and crossing western Cuba, Alma reorganized in the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
, although continued shear prevented strengthening. It moved across Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
on May 25, and on May 27 it dissipated off the coast of Virginia
Virginia
The Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there...
.
The storm first brought gusty winds and heavy rainfall to Jamaica and the Cayman Islands. While it was weakening, Alma produced flooding in central and eastern Cuba, causing seven deaths and forcing 3,000 people to evacuate. Moderate precipitation spread across Florida, while thunderstorms from the storm caused light damage and killed one girl. Moisture from the storm spread up the Atlantic coast.
Meteorological history
Late on May 17, the US National Hurricane CenterNational Hurricane Center
The National Hurricane Center , located at Florida International University in Miami, Florida, is the division of the National Weather Service responsible for tracking and predicting weather systems within the tropics between the Prime Meridian and the 140th meridian west poleward to the 30th...
, reported that a tropical depression had formed about 470 miles (756.4 km) to the southeast of Kingston
Kingston, Jamaica
Kingston is the capital and largest city of Jamaica, located on the southeastern coast of the island. It faces a natural harbour protected by the Palisadoes, a long sand spit which connects the town of Port Royal and the Norman Manley International Airport to the rest of the island...
, Jamaica
Jamaica
Jamaica is an island nation of the Greater Antilles, in length, up to in width and 10,990 square kilometres in area. It is situated in the Caribbean Sea, about south of Cuba, and west of Hispaniola, the island harbouring the nation-states Haiti and the Dominican Republic...
. Over the next couple of days, the depression became better organized as it moved towards the northwest; on May 19 it entered an area of favorable environmental conditions, which enabled the depression to rapidly intensify. On May 20 it strengthened into a tropical storm, at which point it was given the name Alma. That day, it rapidly strengthened under favorable developmental conditions, which included low wind shear
Wind shear
Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...
, strong upper-level outflow
Outflow (meteorology)
Outflow, in meteorology, is air that flows outwards from a storm system. It is associated with ridging, or anticyclonic flow. In the low levels of the troposphere, outflow radiates from thunderstorms in the form of a wedge of rain-cooled air, which is visible as a thin rope-like cloud on weather...
, and apparent eastward inflow
Inflow (meteorology)
Inflow is the flow of a fluid into a large collection of that fluid. Within meteorology, inflow normally refers to the influx of warmth and moisture from air within the Earth's atmosphere into storm systems. Extratropical cyclones are fed by inflow focused along their cold front and warm fronts...
. Later on May 20, a Navy reconnaissance plane recorded winds of 80 mph (128.7 km/h), which proved to be the peak intensity of Alma. It became one of only four Atlantic hurricanes on record in the month of May.
Subsequent to its peak intensity, increasing westerly shear disrupted the storm's circulation and thermal pattern, which caused rapid weakening to tropical storm strength and later tropical depression status. By May 22, the low pressure area became poorly defined after stalling south of Cuba
Cuba
The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...
; with only a few squalls and showers, advisories were discontinued on Alma. The remnants of Alma continued westward near the Cayman Islands, and later turned to the north, passing over western Cuba.
On May 24, the low pressure area reorganized as spiral rainbands became more evident on radar, and Alma was re-classified as a tropical depression. As the depression approached the Florida coast, radar imagery indicated the system remained well-organized, with a spiral band structure around an eye
Eye (cyclone)
The eye is a region of mostly calm weather found at the center of strong tropical cyclones. The eye of a storm is a roughly circular area and typically 30–65 km in diameter. It is surrounded by the eyewall, a ring of towering thunderstorms where the second most severe weather of a cyclone...
feature; however, wind shear limited convection and strength, and Alma moved ashore as a depression near Cedar Key on May 25. It turned northeastward and moved across the southeastern United States, becoming extratropical in North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
on May 27. After moving off the coast of Virginia, the remnants of Alma were absorbed by an approaching cold front
Cold front
A cold front is defined as the leading edge of a cooler mass of air, replacing a warmer mass of air.-Development of cold front:The cooler and denser air wedges under the less-dense warmer air, lifting it...
.
Impact
After Alma weakened from hurricane status, it passed near the Cayman IslandsCayman Islands
The Cayman Islands is a British Overseas Territory and overseas territory of the European Union located in the western Caribbean Sea. The territory comprises the three islands of Grand Cayman, Cayman Brac, and Little Cayman, located south of Cuba and northwest of Jamaica...
on May 21, where winds of up to 65 mph (104.6 km/h) were recorded. Gale force winds and heavy rainfall also occurred in Jamaica. Heavy rains ahead of the storm caused flash flooding in central and eastern Cuba. Seven people died as a result, and several homes were destroyed. The flooding forced the evacuation of 3,000 people in Oriente Province. Inclement weather closed 16 sugar mills, which stalled harvesting that was already behind schedule in the country.
In Florida, the remnants of Alma brought rainfall across most of the state, with some isolated areas experiencing 5 inches (12.7 cm) or more. The highest rainfall from the storm was near Miami, Florida
Miami, Florida
Miami is a city located on the Atlantic coast in southeastern Florida and the county seat of Miami-Dade County, the most populous county in Florida and the eighth-most populous county in the United States with a population of 2,500,625...
, with 6.66 inches (16.92 cm) of rain. The rainfall was beneficial in alleviating drought conditions, although thunderstorms caused hazardous driving conditions in the Florida Keys
Florida Keys
The Florida Keys are a coral archipelago in southeast United States. They begin at the southeastern tip of the Florida peninsula, about south of Miami, and extend in a gentle arc south-southwest and then westward to Key West, the westernmost of the inhabited islands, and on to the uninhabited Dry...
and elsewhere in the state. Small craft warnings were posted along the coast. One girl died from lightning in Miami, and a thunderstorm near Fort Myers damaged some roofs and outbuildings. In Saint Petersburg, flooding disrupted phonelines in about 400 households. Merritt Island
Merritt Island, Florida
Merritt Island is a census-designated place in Brevard County, Florida, United States. It is located on the east coast of the state on the Atlantic Ocean. As of the 2000 census, the population was 36,090. It is part of the Palm Bay – Melbourne – Titusville, Florida Metropolitan Statistical Area...
experienced 45 mph (72.4 km/h) wind gusts. In Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
, South Carolina
South Carolina
South Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...
, North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
, Virginia
Virginia
The Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there...
, and Maryland
Maryland
Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...
, Alma dropped moderate rainfall, with some isolated areas receiving up to 3 inches (7.62 cm). Near Columbia, South Carolina
Columbia, South Carolina
Columbia is the state capital and largest city in the U.S. state of South Carolina. The population was 129,272 according to the 2010 census. Columbia is the county seat of Richland County, but a portion of the city extends into neighboring Lexington County. The city is the center of a metropolitan...
, the remnants of Alma spawned a tornado which destroyed a roof.
See also
- List of tropical cyclones
- List of Atlantic hurricanes
- 1970 Atlantic hurricane season1970 Atlantic hurricane seasonThe 1970 Atlantic hurricane season officially began on June 1, 1970, and lasted until November 30, 1970. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin...