WEATHER EVENT THAT CHANGED LIVES

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🖊 WIKIPEDIA 📸 NATIONAL WEATHER SERVICE

1993 STORM OF THE CENTURY

The 1993 Storm of the Century (also known as the 93 Superstorm, The No Name Storm, or the Great Blizzard of '93/1993) was a large cyclonic storm that formed over the Gulf of Mexico on March 12, 1993. The storm was unique and notable for its intensity, massive size, and wide-reaching effects; at its height, the storm stretched from Canada to Honduras. The cyclone moved through the Gulf of Mexico and then through the eastern United States before moving on to eastern Canada. The storm eventually dissipated in the North Atlantic Ocean on March 15.

Heavy snow was first reported in highland areas as far south as Alabama and northern Georgia, with Union County, Georgia reporting up to 35 inches (89 cm) of snow in the north Georgia mountains. Birmingham, Alabama, reported a rare 13 in (33 cm) of snow. The Florida Panhandle reported up to 4 in (10 cm) of snow, with hurricane-force wind gusts and record low barometric pressures. Between Louisiana and Cuba, the hurricane-force winds produced high storm surges across the big bend of Florida which, in combination with scattered tornadoes, killed dozens of people.

Record cold temperatures were seen across portions of the south and east of the US in the wake of this storm. In the United States, the storm was responsible for the loss of electric power to more than 10 million households. An estimated 40 percent of the country's population experienced the effects of the storm with a total of 208 fatalities.

METEOROLOGICAL HISTORY

During March 11 and 12, 1993, temperatures over much of the eastern United States began to drop as an arctic high pressure system built over the Midwest and Great Plains. Concurrently, an extratropical area of low pressure formed over Mexico along a stationary front draped west to east. By the afternoon of March 12, a defined airmass boundary was present along the deepening low. An initial burst of convective precipitation off the southern coast of Texas (facilitated by the transport of tropical moisture into the region) this presumably enabled initial intensification of the surface feature on March 12. Supported by a strong split-polar jet stream and a shortwave trough, the nascent system rapidly deepened. The system's central pressure fell to 991 mbar (29.26 inHg) by 00:00 UTC on March 13. A powerful low-level jet over eastern Cuba and the Gulf of Mexico enhanced a cold front extending from the low southward to the Isthmus of Tehuantepec. Furthermore, the subtropical jet stream was displaced unusually far south, reaching into the Pacific Ocean near Central America and extending toward Honduras and Jamaica. Intense ageostrophic flow was noted over the southern United States, with winds flowing perpendicular to isobars over Louisiana.

As the area of low pressure moved through the central Gulf of Mexico, a short wave trough in the northern branch of the jet stream fused with the system in the southern stream, which further strengthened the surface low. A squall line developed along the system's cold front, which moved rapidly across the eastern Gulf of Mexico through Florida and Cuba. The cyclone's center moved into north-west Florida early on the morning of March 13, with a significant storm surge in the northwestern Florida peninsula that drowned several people. This initially caused the storm to be a blizzard but also cyclonic.

Barometric pressures recorded during the storm were low. Readings of 976.0 millibars (28.82 inHg) were recorded in Tallahassee, Florida, and even lower readings of 960.0 millibars (28.35 inHg) were observed in New England. Low pressure records for March were set in areas of twelve states along the Eastern Seaboard, with all-time low pressure records set between Tallahassee and Washington, D.C. Snow began to spread over the eastern United States, and a large squall line moved from the Gulf of Mexico into Florida and Cuba. The storm system tracked up the East Coast during Saturday and into Canada by early Monday morning. In the storm's wake, unseasonably cold temperatures were recorded over the next day or two in the Southeast.

FORECASTING

The 1993 Storm of the Century marked a milestone in the weather forecasting of the United States. By March 8, 1993, several operational numerical weather prediction models and medium-range forecasters at the United States National Weather Service recognized the threat of a significant snowstorm. This marked the first time National Weather Service meteorologists were able to predict accurately a system's severity five days in advance. Official blizzard warnings were issued two days before the storm arrived, as shorter-range models began to confirm the predictions. Forecasters were finally confident enough of the computer-forecast models to support decisions by several northeastern states to declare a state of emergency even before the snow started to fall.

IMPACT

The storm complex was large and widespread, affecting at least 26 US states and much of eastern Canada. It brought in cold air along with heavy precipitation and hurricane-force winds which, ultimately, caused a blizzard over the affected area; this also included thundersnow from Georgia to Pennsylvania and widespread whiteout conditions. Snow flurries were seen in the air as far south as Jacksonville, Florida, and some areas of central Florida received a trace of snow. The storm severely impacted both ground and air travel. Airports were closed all along the eastern seaboard, and flights were cancelled or diverted, thus stranding many passengers along the way. Every airport from Halifax, Nova Scotia, to Tampa, was closed for some time because of the storm. Highways were also closed or restricted all across the affected region, even in states generally well prepared for snow emergencies.

Some affected areas in the Appalachian Mountain region saw 5 feet (1.5 m) of snow, and snowdrifts as high as 35 feet (11 m). Mount Le Conte, Tennessee recorded 60 inches (150 cm) of snowfall and Mount Mitchell, N.C. recorded 49 inches (120 cm). The volume of the storm's total snowfall was later computed to be 12.91 cubic miles (53.8 km3), an amount which would weigh (depending on the variable density of snow) between 5.4 and 27 billion tons.

The weight of the record snowfalls collapsed several factory roofs in the South; and snowdrifts on the windward sides of buildings caused a few decks with substandard anchoring to fall from homes. Though the storm was forecast to strike the snow-prone Appalachian Mountains, hundreds of people were nonetheless rescued from the Appalachians, many caught completely off guard on the Appalachian Trail or in cabins and lodges in remote locales. Snow drifts up to 14 feet (4.3 m) were observed at Mount Mitchell. Snowfall totals of between 2 and 3 feet (0.61 and 0.91 m) were widespread across northwestern North Carolina. Boone, North Carolina—in a high-elevation area accustomed to heavy snowfalls—was nonetheless caught off-guard by more than 30 inches (76 cm) of snow and 24 hours of temperatures below 11 °F (−12 °C). Boone's Appalachian State University closed that week, for the first time in its history. Stranded motorists at Deep Gap broke into Parkway Elementary School to survive, and National Guard helicopters dropped hay in fields to keep livestock from starving in northern N.C. mountain counties.

In Virginia, the LancerLot sports arena in Vinton collapsed due to the weight of the record snowfall, forcing the Virginia Lancers of the ECHL to relocate to nearby Roanoke and become the Roanoke Express. Also collapsing were the roofs of a Lowe's store in Christiansburg and the Dedmon Center, at Radford University. Thousands of travelers were stranded along interstate highways in Southwest Virginia. Electricity was not restored to many isolated rural areas for up to three weeks, with power outages occurring all over the east. Nearly 60,000 lightning strikes were recorded as the storm swept over the country for a total of 72 hours. As one of the most powerful, complex storms in recent history, this storm was described as the "Storm of the Century" by many of the areas affected.

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