The end-1998 1998 tornado eruption and derecho is a historic and derecho tornado epidemic that began on the afternoon of May 30 and extended throughout May 31, 1998, in most of the northern part of the State States and south of Ontario from southeastern Montana east and southeast to the Atlantic Ocean. Early tornado outbreaks, including the devastating Spencer tornado, struck southeast of South Dakota on the night of May 30. Spencer's tornado is the second most damaging and deadly tornado in South Dakota history. Eleven people were killed; 7 by tornado and 6 by derecho. More than two million people lose power, some up to 10 days.
Derecho was the harshest line of lightning storms observed on earth during the calendar year of 1998 according to a National Weather Service review shortly after the year ended. It is the culmination of a tremendously heavy derecho season in North-Central America and parts of neighboring Canada and the Northeast of the United States, and this storm combines the characteristics of the two main forms of derecho, progressive and serial derecho. At various points of his evolution, he displays textbooks or recording the manifestations of supercell and derecho-related phenomena such as the right-mover supercell, the evolution of supercells into a meso-scale linear feature that quickly becomes derecho, cumulonimbus with top overshooting and dome, arc echo, vorticity bookend , regular propagation and rotor, front gust, gustnado, rear inflows, classical derecho signatures, atmospheric infrasound and atmospheric effects, haboobs, and wind effects on aquatic bodies including seiches and exposure to water features featured by the wind. The disturbance that originally derecho eventually disappeared off the coast of Norway more than a week later.
Video Late-May 1998 tornado outbreak and derecho
30 Mei Acara Dakota Selatan
The first bad weather of the outbreak was reported at 12:30 noon. in southeast Montana. A few hours later a superkell storm produced 2.75 inches (7.0 cm) of hail in southeastern Montana, kicking out the plague in earnest. Many reports of enormous hail were received throughout the epidemic with the largest official report of 3.00 inches (10 inches) 10 miles (16 km) north of St Lawrence in south-central South Dakota. The hail itself produces thousands of dollars in damage. Many reports of wind and severe straight line damage were also reported. Many reports of storm followers indicate that significant adverse weather events also occur in the sparsely populated areas through which hurricanes pass.
That night, the supercell in southeast Dakota produced a series of tornadoes. The tornado family that crossed the Spencer area was observed by Doppler On Wheels (DOW) radar (Wurman et al. 1997, Wurman 2001). DOW observed tornadoes from before 8:04 am to 8:45 pm local time (01: 04-01: 45 UTC) (Alexander and Wurman 2005) and part of the destructive F4 tornado through Spencer itself from 8: 37-8: 38 (01: 37-01: 38 UTC). DOW measurements of tornadoes over the mostly devastated southern part of Spencer allow direct first (and only December 2006) comparison of measured winds with the rank of damage to the F (or EF) scale as reported in the above reference article. The observed peak Doppler wind near 115 m/s (260 mph) corresponds well with the documented F4 damage.
The DOW observations indicate that the tornado list comes from a damage survey only, and the F-scale rating of the damage, may be incomplete and underestimate the true intensity of the tornado (Wurman and Alexander 2005). A single tornado may be incorrectly characterized as multiple tornadoes due to damage to the observed damage. The DOW measurements show that the F4 tornado may have multiple-vortex structures when attacking Spencer.
Maps Late-May 1998 tornado outbreak and derecho
Confirmed tornado
Events May 30 (South Dakota)
Events May 30 (Derecho)
Spencer, South Dakota F4 tornado
The Spencer, South Dakota tornado is the second most destructive and deadliest tornado in the country's history. It is also the fifth deadliest tornado of the year. It started as a huge tornado, covered in dust in northwestern Farmer, South Dakota in Hanson County, along with the death of a "Fulton" tornado. Continuing east-southeast, he attacked several farmsteads before crossing the Hanson/McCook County line half a mile west-northwest of Spencer. At the moment, the tornado is being observed by the OU Doppler on Wheels crew, whose cellular Doppler radar data shows up to 220 mph of wind in a tornado just a few decades above the ground. It should be noted that while the tornado is rated F4, such wind speeds are consistent with the EF5 tornado on the Fujita Scale Improvement, which was then implemented in 2007.
The tornado carved a 3/8 km path across from the town of Spencer between 8:38 am and 8:44 am CDT, destroying or destroying all but a few homes on the northeast side of the city, and blowing water towers. Some of the houses in town were swept away from their foundations by tornadoes. The tornado killed six people, wounded more than a third of the city's inhabitants, and destroyed most of the city's 190 buildings. Many trees and power lines were destroyed, and vehicles were also destroyed. 5 of 6 casualties occurred in a collapsed apartment building. Damage is estimated at $ 18 million. The city population was reduced immediately after less than half of what was previously to the tornado, 315-145 in April 1999.
30-31 May Southern Great Lakes derecho
This derecho starts from a low-pressure developing system that moves to the Great Plains and Great Lakes in the north. Derecho is formed from the same storm system that spawned Spencer, South Dakota Tornado, which killed six people. The super thunderstorm that produced the tornado turned into a derecho that killed six others. It will be the most damaging natural disaster to reach the Upper Midwest in recent memory.
Minnesota
The biggest damage in Minnesota takes place in the northern end of Sibley and McLeod County. Winds range from 80-100 mph (130-160 km/h) in both districts.
After the derecho darted through Minnesota, tens of thousands of trees were blown up. There are 500,000 customers without electricity. More than 100 homes are destroyed or damaged and can not be repaired. Twenty-two people were injured. Derecho caused damage to $ 50 million in southern Minnesota and northern Wisconsin.
Wisconsin
Derecho ran across Wisconsin in just three hours killing one person in Washington County when a tree fell onto the roof and into his bed where he slept. It injured 37 people in Wisconsin. Many utility companies and emergency customers say that this is the most damaging storm events in 100 years. Five thousand homes and businesses were damaged and 24 destroyed.
The south-central, southeastern, and middle-eastern regions of Wisconsin reported winds of more than 100 mph (160 km/h) from this storm complex with an official official status record of 128 mph (206 km/h). ) 3 miles (4.8 km) northeast of Watertown in Dodge County. Like other derechos like the July 4, 1977 attacks in northern Wisconsin, there are other informal reports of higher winds and such forecasts, including 102 mph (164 km/h) winds maintained for several minutes and gusts of up to 140 mph (230 km/hour) also in Dodge County and/or the adjacent section of Fond du Lac County.
The roar of the derecho sounded as far as 30 miles (48 km) as the storm hit this area. Other road signs and metallic structures are found thrown and even roughly twisted in the 100 mph-plus winds of eastern Dane County through Dodge and Fond du Lac and Washington County - evidence of straight-line winds and widespread downburst rotor in this area as well as many other points along the path of the storm, and the sound of wind and possibly hail and the infrasound effects of some parts of the storm complex are also reported. In the latter case, some people report a feeling of strange pressure and dogs, cats, and raccoons become wild.
Derecho also caused a boating accident by producing a seiche in Lake Michigan that was reportedly about 10 feet (3.0 meters) tall as it first hit the Michigan Lake Michigan coastline further north in Muskegon County.
Central Great Lakes
The storm raced through Michigan in just two hours with an average speed of 70 mph (110 km/h). Four people died in Michigan, and 146 were injured. Total damage is estimated at $ 172 million (1998 dollars). 250 homes and 34 businesses were destroyed. At Grand Haven the Story & amp; Chimney Clark at Piano Factory Condominiums was destroyed when the force of strong winds caused it to collapse, and trees collapsed across the city, some falling to the roof. Damage in Spring Lake is worse, because the zones are heavily localized from higher winds. Mill Pointe Condominiums suffered serious damage, including the collapse of one unit. Others are then deleted. A factory loses its roof in a storm, and a number of businesses are badly damaged, which can not be fixed. Country Estates Mobile Home park also suffered serious damage. Widespread damage to Grandville (about 30 miles (48 km) inland causes the city to shut down, with no traffic allowed on the day after the derecho passage.A woman died in Pinconning, about 130 miles (210 km) north of Detroit, when a tree fell in his home.
Derecho will break the record for the biggest ever power outage in the state of Michigan (but then surpassed by the 2003 North American outage). 860,000 people lost strength, slightly more than the sum of Southern Great Lakes Derecho in 1991. It destroyed five 345-kilovolt transmission towers owned by Consumer Energy.
Thirteen districts in Central Lower Michigan are declared a federal disaster area.
One person drowned in Ontario when his ship was turned upside down by a strong crane wind. Buildings in Toronto lost many windows and significant damage was observed in areas such as Trenton, Napanee, Picton and Kingston. The activity of thunderstorms was also reported in Ottawa and Montreal, Quebec, but without damage.
This caused $ 300,000 damage in central New York before it was reformed into a tornado outbreak around 11am on the morning of May 31st.
Summary
Overall, the derecho traveled 975 miles (1,569 km) from southern Minnesota to central New York in 15 hours at an average speed of 65 mph (105 km/h). It became one of the most destructive derecho events in North American history, causing $ 300 million damage.
May 31 tornado New York and Pennsylvania
On Sunday, May 31, the cold front Friday, halted in southern Pennsylvania, began to move quickly back north as a warm front due to the strong low pressure approaching the Great Lakes. To the north of the warm front, most of the Hudson Valley and Western New England are under the cold and stable sea air mass, as a result of the southeast winds of the Atlantic Ocean. Around 8 am, the warm front lies approximately above the Mohawk River to the center and north of Massachusetts, producing a powerful thunderstorm. After a warm front, sunlight broke out and strong warming began in the Northeast with temperatures rising rapidly from the 50s to 70s to the 80s, and dew points skyrocketing from the 40s to 60s, an upper part. the surface winds start blowing from the southeast at about 30 mph, while the intermediate winds come from the southwest at 60 to 80 mph, and the jetstream winds still range from 120-150 mph from the west. A high degree of instability is also present. This creates a very highly cut environment in the Northeast.
The Hurricane Prediction Center issues High Risk for Severe Thunderstorms in Northern Pennsylvania, Most of New York, Western Massachusetts, and West Vermont. A High Risk has never been issued for the Northeast United States, and has not been since this incident. This shows a very dangerous weather situation for the region of the country, a more general situation in Plains State and Midwest.
At about 1 pm Michigan derecho moved to New York from Ontario and weakened rapidly. The rotting crust line broke into discrete convection over New York and Pennsylvania, which rapidly re-intensified into tornadic supercells.
The most damaging tornado of the day was the F3 that ripped through Mechanicville and neighboring Stillwater. This caused major damage to the old Mechanicville industrial part located on Routes 4 and 32 along the Hudson River. One of the two historical chimneys (visible from 2 miles away) was torn down by a tornado. In 2005, other chimneys and buildings that joined it were bulldozed. The tornado was rated F3 (wind estimated at 200 MPH at the time) on the Fujita scale, and a width of 970 yards (0.55 miles). In total, 70 homes and businesses were totally destroyed, and hundreds of others were damaged. Massive deforestation takes place along that path as well. 68 people were injured, but no casualties occurred. The pink insulation is reportedly falling from the sky ahead of the tornado, in Valley Falls, New York, 12 miles east of Mechanicville. Negative films from Mechanicville are reported to be found there as well.
Many other powerful tornadoes landed in northern New York and Pennsylvania that night, some of which reached the intensity of F2 to F3. One F3 caused major damage in the city of Binghamton. The other F3 caused major damage in the village of Windsor. This outbreak is probably the most intense, widespread, and long-lasting bad weather event in modern New York state history. The other less intense tornadoes touch in the surrounding countries.
Confirmed tornado
Events May 31
See also
- List of famous derecho events
References
External links
- "The Southern Great Lakes Derecho of 1998" (Center for Hurricane Prediction)
- "The Upper Midwest is hit by a hurricane storm" (CNN)
- Detailed SPC overview
- NWS overview
- CIMMS satellite imagery and meteorological analysis
- Spencer Doppler-on-wheel CSWR page
Source of the article : Wikipedia
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