Storm of the Century (1993)

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Storm of the Century (1993)

Satellite image by NASA of the superstorm on March 13, 1993, at 10:01 UTC.
Storm type:	Cyclonic blizzard, Nor'easter
Formed:	March 11, 1993
Dissipated:	March 15, 1993
Maximum amount1:	60 inches (152.4 cm) - Mt. Le Conte, TN
Lowest pressure:	960 mbar (hPa)
Damages:	$6-10 billion (2005 USD)[1]
Fatalities:	300 total
Areas affected:	Most of eastern and southern North America
1Maximum snowfall or ice accretion

The Storm of the Century, also known as the ’93 Superstorm, No-Name Hurricane, the White Hurricane, or the (Great) Blizzard of 1993, was a large cyclonic storm that occurred on March 12–March 15, 1993, on the East Coast of North America. It is unique for its intensity, massive size and wide-reaching effect. At its height the storm stretched from Canada to Central America, but its main impact was on the Eastern United States and Cuba. Areas as far south as central Alabama and Georgia received 4 to 6 inches of snow and areas such as Birmingham, Alabama, received up to 12 inches with isolated reports of 16 inches. Even the Florida Panhandle reported up to 2 inches, with hurricane-force wind gusts and record low barometric pressures. Between Florida and Cuba, hurricane-force winds produced extreme storm surges in the Gulf of Mexico, which along with scattered tornadoes killed dozens of people.

Contents 1 Formation 1.1 Forecasting 2 The storm 2.1 The blizzard 2.2 Subtropical derecho 2.3 Tornado table 2.4 Confirmed tornadoes 3 Impact 4 Storm amounts 5 See also 6 References 7 External links

[edit] Formation

A "disorganized area of low pressure" that formed in the Gulf of Mexico joined an arctic high pressure system in the Midwestern Great Plains, brought into the mid-latitudes by an unusually steep southward jet stream. These factors combined to produce unusually cold temperatures across the eastern half of the United States.

[edit] Forecasting

The 1993 Storm of the Century marked a milestone in U.S. weather forecasting. By March 8 (and by some accounts even earlier), several operational numerical weather prediction models and medium-range forecasters at the US National Weather Service recognized the threat of a significant snowstorm. By the 12th, many had reviewed the data and were convinced that a serious threat loomed overhead. This marked the first time that National Weather Service meteorologists were able to accurately predict 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 in the computer-forecasted models to support decisions by several Northeastern U.S. states to declare a State of Emergency before the snow even started to fall.^[2]
In the South, however, temperatures in the days prior to the storm were typical for early March. Although large fluctuations in temperature are not unusual in the deep south, many residents doubted that freezing temperatures could return so rapidly; nor that snow--which does not fall very often or very much there--would be just around the corner. Many local TV news stations were reluctant to even broadcast the forecasted models, due to the extreme numbers being predicted by the computers, but the models turned out to be right.

[edit] The storm

During Friday March 12, temperatures over much of the eastern United States began to fall quickly. The area of low pressure rapidly intensified during the day on Friday and moved into northwest Florida by early Saturday morning. As this happened snow began to spread over the eastern United States, and a large squall line moved from over the Gulf of Mexico into Florida and Cuba. The low tracked up the east coast during the day on Saturday and into Canada by early Monday morning.

[edit] The blizzard

Temperatures accompanying the storm were unseasonably cold for early spring: average daily maximum temperatures, in mid-March, are around 46°F (8°C) in Boston, 51°F (11°C) in Philadelphia, Pennsylvania, and 65°F (18°C) in Atlanta. During the 1993 storm, these places were all near or below freezing, and parts of New England saw daily maximum temperatures as low as 14°F (-10°C). Record low temperatures for March were recorded in much of the Southern U.S. Farther to the South, numerous supercells developed over the state of Florida, spawning eleven tornadoes and killing seven people.

This storm complex was massive, affecting at least 26 U.S. states and much of eastern Canada. Bringing cold air along with heavy precipitation and hurricane force winds, it caused a blizzard over much of the area it affected. The storm brought snow as far south as northern Florida, thundersnow from Texas to Pennsylvania, and whiteout conditions. Some affected areas saw more than 3.5 feet (1.1 m) of snow, and snowdrifts were as high as 35 feet (10.7 m). Central and Southern Florida saw no snow, but tornadoes and severe thunderstorms, resultant from the storm, occurred there and in Cuba. Responsible for 300 deaths and the loss of electric power to over 10 million, it is purported to have been directly experienced by over 130 million people in the United States, about half the country's population at that time. Every airport from Halifax, Nova Scotia to Atlanta, Georgia was closed for some time because of the storm. The volume of the storm's total snowfall was later computed to be 12.91 mi³ (53.96 km³), an amount which would weigh (depending on the variable density of snow) between 5.4 and 27 billion tonnes.

Barometric pressures recorded during the storm were also unusually low: readings of 28.35 inHg (960 mb or hPa) were observed in New England. Usually, such low readings are observed only in hurricanes (generally of Category 2 or 3 intensity on the Saffir-Simpson hurricane scale), which peak at almost the exact opposite time of year, or in other cyclonic storms far out to sea. It also pushed a storm surge ashore on the Florida panhandle, drowning a few people taken by surprise at the storm's ferocity. (This incident is featured occasionally on reruns of Storm Stories.)

As one of the most powerful storms in recent history, the storm has been described as the "Storm of the Century" by many of the areas affected. The last blizzard to have such an effect on the Southeast was the Great Blizzard of 1899.

[edit] Subtropical derecho

Besides producing record low barometric pressure across a swath of the Southeast and Mid-Atlantic states, and one of the nation's biggest snowstorms, the low produced a potent squall line ahead of its cold front. The squall line produced a serial derecho as it moved into Florida and Cuba around midnight on March 13. Straight-line winds gusted above 100 mph/85 kts (160 km/h) at many locations in Florida as the squall line moved through.

A substantial storm surge was also generated along the gulf coast from Appalachee Bay in the Florida panhandle all the way around to Southwest Florida. Especially hard hit was Hernando County north of Tampa, where the coast faces northwest; right into the teeth of the approaching squall (see map).

Storm surges there reached up to 12 feet; higher than many hurricanes. With little advanced warning of incoming severe conditions, some coastal residents were awakened in the early morning of March 13th to find the waters of the Gulf of Mexico rushing into their homes.^[3] Overall, the storm's surge, winds, and tornadoes damaged or destroyed 18,000 homes and killed at least 26 people in Florida.^[4]

The supercells in the derecho produced ten tornadoes in the United States. One tornado killed three people when it struck a home which later collapsed, pinning the occupants under a fallen wall.

In Cuba, wind gusts reached 100 mph (160 km/h) in the Havana area. A survey conducted by a research team from the Institute of Meteorology of Cuba suggests that the maximum winds could have been as high as 130 mph (210 km/h). It is the most damaging squall line ever recorded in Cuba.

There was widespread and significant damage in Cuba, with damages estimated as intense as F2.^[5] The squall line finally moved out of Cuba near sunrise, leaving 10 deaths and US$1 billion in damage on the island.

In the image above, measured gusts in mph are plotted (blue numbers). "+" symbols indicate the locations of wind damage or estimated wind gusts above severe limits (58 mph or greater). Red dots and paths indicate tornado events. Small red numbers indicate tornado intensities in F-scale. The approximate location of the squall line "gust front" is shown in two hour increments (curved purple lines).

[edit] Tornado table

Confirmed Total	Confirmed F0	Confirmed F1	Confirmed F2	Confirmed F3	Confirmed F4	Confirmed F5
11	5	3	3	0	0	0

[edit] Confirmed tornadoes

F#	Location	County	Time (UTC)	Path length	Damage
Florida
F2	NW of Chiefland	Levy	0438	1 miles (1.6 km)	3 deaths
F1	E of Crystal River	Citrus	0438	0.5 miles (0.8 km)
F0	Treasure Island area	Pinellas	0500	0.1 miles (0.16 km)
F0	New Port Richey area	Pasco	0504	0.1 miles (0.16 km)
F2	Ocala area	Marion	0520	15 miles (24 km)
F1	N of La Crosse	Alachua	0520	0.8 miles (1.3 km)	1 death
F2	NW of Howey Height to Alamonte Springs	Lake	0530	30 miles (48 km)	1 death
F0	Tampa area	Hillsborough	0530	0.1 miles (0.16 km)
F1	Jacksonville area (1st tornado)	Duval	0600	0.8 miles (1.3 km)
F0	Bartow area	Polk	0600	0.1 miles (0.16 km)
F0	Jacksonville area (2nd tornado)	Duval	0610	0.1 miles (0.16 km)
Sources: Tornado History Project Storm Data - March 12, 1993, Tornado History Project Storm Data - March 13, 1993

[edit] Impact

In the South, where public works facilities (in most areas) generally have no reason to be prepared for snow removal, the storm is vividly remembered because it resulted in a complete shutdown of that region for three days. Cities that usually receive little snowfall, such as Chattanooga, Tennessee, received anywhere from 2 to 4 feet of snow, causing some municipalities to adopt at least an emergency winter-weather plan for the future where one may not have existed before. Birmingham, Alabama, which normally receives 1 inch in a year, received 17 inches shattering the records for most snow in a single storm, a single month, and even a single season. The psychological impact in the Southern states, where average high temperatures in March tend to run into the 60s Fahrenheit (the upper teens Celsius), was magnified by the fact that it struck a week before spring. Two NASCAR weekends -- one at Atlanta Motor Speedway, where the Motorcraft 500 Winston Cup round was postponed six days, and the Slick 50 300 Busch Grand National Series event was postponed eight months, and the Miller 500 Classic weekend for the Busch Grand National cars and Late Models at Martinsville Speedway was postponed two months because of the aftereffects of the soggy grounds -- were called off because of the weather and its ensuing rain; Birmingham recorded a record low of 2 degrees Fahrenheit during the storm. Syracuse, New York, which is accustomed to heavy snowfall due to yearly lake-effect snow storms, received a record 43 inches from the storm, while snowfall totaled over 12 inches in New York City and 2 feet of snow fell in Hartford, Connecticut and Pittsburgh, Pennsylvania.

The weight of record snows collapsed many factory roofs in the South, and snowdrifts on the windward sides of buildings caused a few decks with substandard anchors 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 visiting cabins and lodges in remote locales. The heaviest snow recorded was at Newfound Gap, where U.S. 441 crosses the Tennessee and North Carolina border, with five feet (1.5 m);^{[citation needed]} drifts up to 14 feet (4.3 m) were observed at Mount Mitchell. Snowfall totals of between 2 and 3 feet were widespread across northwestern North Carolina. Boone, North Carolina — in a high-elevation area accustomed to heavy snowfalls — was nonetheless caught off guard by 24 hours of below zero Fahrenheit temperatures along with storm winds, which (according to NCDC storm summaries) gusted as high as 110 miles per hour. Electricity was not restored to many isolated rural areas for a week or more, 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 seventy-two hours, and many may remember their local news organizations touting the term "thundersnow."

Overall, the Blizzard of 1993 caused a total of $6.6 billion of damage.

Across the Northeastern states and eastern Canadian provinces, the storm put down an average of 15 inches (40 cm) of snow, which, though most certainly heavy, is not legendary by most local standards, but still somewhat unusual for mid-March, especially for the southernmost parts of the region such as the Baltimore-Washington area. New England residents tend to point to the Blizzard of 1978 as their "storm of the century," due largely to its unrelenting snowfall, which managed to incapacitate the weather-hardened region, while Mid-Atlantic residents tend to point to the Blizzard of 1996 for similar reasons. Based on widespread effects, barometric pressures, wind speeds and satellite images, however, there is little doubt that the storm of 1993 was the more remarkable.

[edit] Storm amounts

Storm Snow Totals Totals are for the main system only.
Mount Le Conte, TN	60 in (152.4 cm)[1]
Mount Mitchell, NC	50 in (127 cm)[1]
Snowshoe, WV	44 in (111.8 cm)[6]
Syracuse, NY	43 in (109.2 cm)[1]
Latrobe, PA	36 in (91.4 cm)[6]
Lincoln, NH	35 in (88.9 cm)[6]
Albany, NY	27 in (68.6 cm)[1]
Pittsburgh, PA	25 in (63.5 cm)[1]
Hartford, CT	24 in (61 cm)
London, KY	22 in (55.9 cm)[7]
Chattanooga, TN	20 in (50.8 cm)[6]
Asheville, NC	19 in (48.2 cm)[6]
Ottawa, ON	17.7 in (45 cm)[8]
Allentown, PA	17.6 in (44.7 cm)
Birmingham, AL	17 in (43 cm)[6]
Montreal, QC	16.1 in (41 cm)[9]
Washington, D.C.	13 in (33 cm)[6]
New York, NY	12 in (30.5 cm)
Atlanta, GA	4 in (10.1 cm)[6]
Mobile, AL	3 in (7.6 cm)[1]
Hammond, LA	2 in (5.1 cm)[1]

[edit] See also

• List of derecho events

[edit] References

[edit] External links

• NWS Service Assessment
• The Big One! A Review of the March 12-14, 1993 "Storm of the Century" (PDF)
• Summary of the Subtropical Derecho (NOAA)