Tropical Storm Bertha was a rapidly forming and short-lived off-season tropical storm that affected the

Eastern United States The Eastern United States, often abbreviated as simply the East, is a macroregion of the United States located to the east of the Mississippi River. It includes 17–26 states and Washington, D.C., the national capital. As of 2011, the Eastern ...

in late May 2020. The second

named storm Tropical cyclones and subtropical cyclones are named by various warning centers to simplify communication between forecasters and the general public regarding forecasts, watches and warnings. The names are intended to reduce confusion in the ...

of the very active

2020 Atlantic hurricane season The 2020 Atlantic hurricane season was the most active Atlantic hurricane season on record, in terms of the number of systems. It featured a total of 31 tropical and subtropical cyclones, with all but one cyclone becoming a named storm. ...

, Bertha originated from a

trough Trough may refer to: In science * Trough (geology), a long depression less steep than a trench * Trough (meteorology), an elongated region of low atmospheric pressure * Trough (physics), the lowest point on a wave * Trough level (medicine), the l ...

in the

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. The

National Hurricane Center The National Hurricane Center (NHC) is the division of the United States' NOAA/National Weather Service responsible for tracking and predicting tropical weather systems between the IERS Reference Meridian, Prime Meridian and the 140th meridian ...

(NHC) only anticipated slight development as the trough moved over southern

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

, bringing torrential rainfall. The system rapidly organized on May 27 after it emerged into the western

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

, developing a small, well-defined circulation. That day, the disturbance developed into Tropical Storm Bertha east of

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, and a few hours later it moved ashore near

Isle of Palms, South Carolina Isle of Palms is a city in Charleston County, South Carolina, Charleston County, South Carolina, United States. At the 2010 census, the population was 4,133. Isle of Palms is a barrier island on the South Carolina coast. The city is included with ...

with peak winds of . The storm weakened over land and dissipated late on May 28 over

West Virginia West Virginia is a mountainous U.S. state, state in the Southern United States, Southern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States.The United States Census Bureau, Census Bureau and the Association of American ...

. The storm and its precursor disturbance caused heavy rainfall and

flash flood A flash flood is a rapid flooding of low-lying areas: washes, rivers, dry lakes and depressions. It may be caused by heavy rain associated with a severe thunderstorm, hurricane, or tropical storm, or by meltwater from ice and snow. Flash f ...

ing in southern Florida, as well as spawning a brief

tornado A tornado is a violently rotating column of air that is in contact with the surface of Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. It is often referred to as a twister, whirlwind or cyclone, although the ...

. In South Carolina, Bertha produced above normal tides and locally heavy rainfall, causing minor flooding. As the storm moved into

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

, its remnants produced a brief

, while

rip current A rip current (or just rip) is a specific type of water current that can occur near beaches where waves break. A rip is a strong, localized, and narrow current of water that moves directly away from the shore by cutting through the lines of bre ...

s resulted in several water rescues in Surf City. According to the

National Centers for Environmental Information The National Centers for Environmental Information (NCEI) is a U.S. government agency that manages one of the world's largest archives of atmospheric, coastal, geophysical, and oceanic data. The current director is Deke Arndt. NCEI is operate ...

, Bertha caused $130,000 (2020

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) in damage.

Meteorological history

A trough, or elongated

low pressure area In meteorology, a low-pressure area (LPA), low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. It is the opposite of a high-pressure area. Low-pressure areas are commonly associated with inclem ...

, developed in the southeastern Gulf of Mexico on May 24. By that time, the trough extended across southern Florida into the western Atlantic Ocean, producing a widespread area of thunderstorms. The

(NHC) first mentioned the system in a special tropical weather outlook on May 25, assessing a 20% chance for tropical

cyclogenesis Cyclogenesis is the development or strengthening of Cyclonic rotation, cyclonic circulation in the atmosphere (a low-pressure area). Cyclogenesis is an umbrella term for at least three different processes, all of which result in the development of ...

, due to expected strong

wind shear Wind shear (; also written windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical ...

, the proximity to land, and dry air. By that time, the trough extended across southern Florida into the western Atlantic Ocean, producing a widespread area of thunderstorms. A weak surface low formed near

Orlando, Florida Orlando ( ) is a city in and the county seat of Orange County, Florida, United States. The city proper had a population of 307,573 at the 2020 census, making it the fourth-most populous city in Florida behind Jacksonville, Florida, Jacksonville ...

early on May 26, which moved northeast over water by early the following day. Subsequently, the NHC increased the system's development potential to 30%. Early on May 27, the system developed a well-defined center underneath an area of organized

thunderstorm A thunderstorm, also known as an electrical storm or a lightning storm, is a storm characterized by the presence of lightning and its acoustics, acoustic effect on the Earth's atmosphere, known as thunder. Relatively weak thunderstorm ...

s. In addition, an offshore buoy recorded tropical storm-force winds. The NHC estimated that the system developed into Tropical Storm Bertha at 06:00

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that day while located about east of

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. Operationally, it was not until 12:30 UTC that the NHC had initiated advisories on Bertha. The storm had characteristics of both a

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

and a

subtropical cyclone A subtropical cyclone is a weather system that has some characteristics of both tropical cyclone, tropical and extratropical cyclones. As early as the 1950s, meteorologists were uncertain whether they should be characterized as Tropical cyclone ...

, but the NHC designated it as tropical due to the storm's small

radius of maximum wind The radius of maximum wind (RMW) is the distance between the center of a cyclone and its band of strongest winds. It is a parameter in atmospheric dynamics and tropical cyclone forecasting. The highest rainfall rates occur near the RMW of tropi ...

s. Upon its formation, Bertha was moving northwestward around the western side of a

ridge A ridge is a long, narrow, elevated geomorphologic landform, structural feature, or a combination of both separated from the surrounding terrain by steep sides. The sides of a ridge slope away from a narrow top, the crest or ridgecrest, wi ...

over the western Atlantic. At 12:00 UTC, the storm had reached peak winds of ; this was based on observations from buoys and the storm's well-defined curved

rainband A rainband is a cloud and precipitation structure associated with an area of rainfall which is significantly elongated. Rainbands in tropical cyclones can be either stratiform or convective and are curved in shape. They consist of showers and th ...

s near the center. Its gale-force winds extended only from the center. At 13:00 UTC on May 27, 2020, Bertha made

landfall Landfall is the event of a storm moving over land after being over water. More broadly, and in relation to human travel, it refers to 'the first land that is reached or seen at the end of a journey across the sea or through the air, or the fact ...

near

while at peak intensity. The storm quickly weakened as it progressed inland, falling to tropical depression status within a few hours of moving ashore. The depression turned toward the north, moving through western North Carolina and into western Virginia. Early on May 28, Bertha transitioned into an

extratropical cyclone Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of p ...

, which persisted another 12 hours before dissipating over northern West Virginia.

Preparations and impact

Florida

The precursor disturbance to Tropical Storm Bertha caused a significant, multi-day rainfall event across South Florida, reaching across several locations. The peak 72–hour accumulation was , recorded in

Miami Miami is a East Coast of the United States, coastal city in the U.S. state of Florida and the county seat of Miami-Dade County, Florida, Miami-Dade County in South Florida. It is the core of the Miami metropolitan area, which, with a populat ...

. Rainfall rates of an hour contributed to a 24-hour total of there, more than doubling the previous daily rainfall record and resulting in the city's most significant rain event in eight years. The precursor disturbance spawned an EF1 tornado in Aladdin City, which produced winds of and was on the ground for . The tornado damaged trees and fences, and overturned several campers. Thunderstorms produced

hail Hail is a form of solid Precipitation (meteorology), precipitation. It is distinct from ice pellets (American English "sleet"), though the two are often confused. It consists of balls or irregular lumps of ice, each of which is called a hailsto ...

up to in diameter near

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, as well as wind gusts estimated up to . In and around Miami, the rains flooded homes and roadways, especially in close proximity to canals. Some homes even reported partial roof collapses throughout Hallandale Beach and Hollywood as a result of the heavy precipitation. Local police in El Portal asked that the South Florida Water Management District open floodgates to relieve flooding in those canals. Floodwaters entered vehicles and buildings in

Miami Beach Miami Beach is a coastal resort city in Miami-Dade County, Florida, United States. It is part of the Miami metropolitan area of South Florida. The municipality is located on natural and human-made barrier islands between the Atlantic Ocean an ...

and

Hialeah Hialeah ( ; ) is a city in Miami-Dade County, Florida, United States. With a population of 223,109 as of the 2020 census, it is the sixth-largest city in Florida. It is the second largest city by population in Miami-Dade County in the Miami met ...

, prompting several water rescues. Hialeah's mayor asked residents to remain indoors accordingly. Days of heavy rainfall prompted local National Weather Service offices to issue flash flood warnings, and sporadic severe thunderstorms prompted additional advisories. Strong wind gusts uprooted a tree onto

Route A1A State Road A1A (SR A1A) is a major north–south Florida State Road consisting of seven separate sections running a total of along the Atlantic Ocean, from Key West at the southern tip of Florida, to Fernandina Beach, Florida, Fernandina ...

. As the low associated with Bertha moved northeastward, it also produced minor flooding near

St. Augustine Augustine of Hippo ( , ; ; 13 November 354 – 28 August 430) was a theologian and philosopher of Berber origin and the bishop of Hippo Regius in Numidia, Roman North Africa. His writings deeply influenced the development of Western philosop ...

due to heavy rainfall. Unsettled weather related to Bertha forced the cancellation of the planned Crew Dragon Demo-2 launch on May 27 from

Cape Canaveral Cape Canaveral () is a cape (geography), cape in Brevard County, Florida, in the United States, near the center of the state's Atlantic Ocean, Atlantic coast. Officially Cape Kennedy from 1963 to 1973, it lies east of Merritt Island, separated ...

. Damage across the state was estimated at $71,000.

Carolinas

Ahead of Bertha's development, the NHC warned of the potential that the system could cause flash flooding, dangerous marine conditions, life-threatening surf and rip currents. Upon Bertha's development, the NHC issued a

tropical storm warning Tropical cyclone warnings and watches are alerts issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of tropical storm or hurricane intensity. They are notices to the local pop ...

for the South Carolina coastline from Edisto Beach to South Santee River, only an hour before landfall. The National Hurricane Center warned that given very saturated antecedent conditions, rainfall from Bertha could produce life-threatening flash flooding and river flooding. The 2020 Alsco Uniforms 500, held in Charlotte, North Carolina, was also postponed a day due to the possibility of bad weather. Upon moving ashore, Bertha produced a small

storm surge A storm surge, storm flood, tidal surge, or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low-pressure weather systems, such as cyclones. It is measured as the rise in water level above the ...

, causing some

coastal flooding Coastal flooding occurs when dry and low-lying land is submerged (flooded) by seawater. The range of a coastal Flood, flooding is a result of the elevation of floodwater that penetrates the inland which is controlled by the topography of the coas ...

Wrightsville Beach, North Carolina Wrightsville Beach is a town in New Hanover County, North Carolina, United States. Wrightsville Beach is just east of Wilmington, North Carolina, Wilmington and is part of the Wilmington metropolitan area. The population was 2,477 at the 2010 Uni ...

recorded water levels above normal, the highest tides related to the storm. Bertha also dropped rainfall across South Carolina, reaching in some locations. Wind gusts on land reached in

Winyah Bay Winyah Bay is a coastal estuary that is the confluence of the Waccamaw River, the Pee Dee River, the Black River, and the Sampit River in Georgetown County, in eastern South Carolina. Its name comes from the Winyah people, who inhabited th ...

. Floods in

Charleston, South Carolina Charleston is the List of municipalities in South Carolina, most populous city in the U.S. state of South Carolina. The city lies just south of the geographical midpoint of South Carolina's coastline on Charleston Harbor, an inlet of the Atla ...

inundated streets and cars. A few streams exceeded their banks in Lancaster County, flooding some bridges. Minor power outages occurred throughout South Carolina. A drowning was reported in

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due to rip currents from Bertha after the storm made landfall. Heavy rainfall in North Carolina flooded roads and streams near Charlotte. The storm's remnants spawned a brief

EF0 The Enhanced Fujita scale (abbreviated EF-Scale) is a scale that rates tornado intensity based on the severity of the damage a tornado causes. It is used in the United States and France, among other countries. The EF scale is also unofficially ...

in northern Warren County, which destroyed a building and uprooted a few trees. Damage caused by tornado was estimated at $50,000, although it was not considered to be directly associated with Bertha. At least ten people required rescue in Surf City from rip currents.

Elsewhere

The remnants of Bertha later brought rainfall to West Virginia, resulting in flash flooding in Kanawha County that inundated some roads. Statewide damage was estimated at $16,000. Rainfall from Bertha extended into northeastern Ohio, where it was the earliest former tropical cyclone to affect the state on record.

Pittsburgh Pittsburgh ( ) is a city in Allegheny County, Pennsylvania, United States, and its county seat. It is the List of municipalities in Pennsylvania#Municipalities, second-most populous city in Pennsylvania (after Philadelphia) and the List of Un ...

, Pennsylvania recorded of rainfall related to the storm.

References

External links

*The NHC'
advisory archive on Tropical Storm Bertha
{{DEFAULTSORT:Bertha Bertha (2020) Hurricanes in Canada Hurricanes in Florida Hurricanes in New York (state) Hurricanes in North Carolina Hurricanes in Ohio Hurricanes in Pennsylvania Hurricanes in South Carolina Hurricanes in Virginia 2020 Atlantic hurricane season Bertha (2020) Tropical cyclones in 2020 Hurricanes in West Virginia