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June 2012 North American derecho

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June 2012 Derecho
Composite radar image as the storm moved from Indiana to Virginia
Duration~18 hours (10:00 AM-4:00 AM)
Tornadoes
confirmed		1 reported (Newcomerstown, Ohio)
Max. rating1unrated tornado
Largest hail2.75 Inches (Bismarck, Illinois)[1]
Fatalities22
DamageUncalculated (estimated in the hundreds of millions of dollars)
Areas affectedUnited States Midwest, United States Mid-Atlantic
1Most severe tornado damage; see Enhanced Fujita scale

The June 2012 Mid-Atlantic and Midwest derecho was one of the most destructive and deadly fast-moving severe thunderstorms in North American history. The progressive derecho tracked across a large section of the Midwestern United States and across the central Appalachians into the Mid-Atlantic States on the afternoon and evening of June 29, 2012, and into the early morning of June 30, 2012. It resulted in 22 deaths, widespread damage and millions of power outages across the entire affected region. The storm prompted the issuance of four separate severe thunderstorm watches by the Storm Prediction Center. A second storm in the late afternoon caused another watch to be issued.

Storm overview

Severe weather reports from the Storm Prediction Center on June 29

The beginnings

Warnings from the NWS on June 29-30. Red are tornado warnings, yellow are severe thunderstorm warnings, green are flash flood warnings, and purple are special marine warnings.

The storm started as a small thunderstorm cell in central Iowa and continued into Illinois, developing into a mesoscale convective system (MCS) while mostly below severe limits at the time. Due to an extremely hot and highly unstable atmosphere with CAPE values in excess of 5,000 J/kg and temperatures on the south side of a stationary front well in excess of 100°F (37.8°C) prompting widespread excessive heat warnings[3], it quickly intensified, and the storm complex became fully severe as it crossed over the Chicago metropolitan area early in the afternoon of June 29 for the Chicago area and much of northern Indiana. The first severe thunderstorm watch of the afternoon was issued at 11:50 a.m. CDT (1650 UTC) just before the storm crossed over Chicagoland.[4]

The MCS becomes a derecho

A moderate risk area was issued by the SPC for the areas downstream of the derecho. It was later expanded eastward.

As the storm tracked eastward into Indiana, it became a derecho and wind gusts increased substantially, peaking as high as 91 mph (147 km/h) in Fort Wayne, equivalent to a Category 1 hurricane, at least in gusts. By that time, the system had taken on a well-defined bow echo shape, the classic indicator of a derecho.[5] A severe thunderstorm watch, with high wind probabilities (although not a PDS watch) was issued for the majority of Ohio, much of West Virginia, and parts of Indiana and Kentucky at 3:05 p.m. EDT (1905 UTC) as the storm traversed north-central Indiana.[6] Moving southeastward to east-southeastward at about 60 mph (95 km/h)—a speed and trajectory that the derecho maintained for its entire lifespan—it followed the stationary front and increased in size as it entered Ohio in the mid-afternoon hours, affecting a large portion of the state. Since the derecho was clearly underway and expected to last a long time, the SPC increased the threat level to a moderate risk of severe weather at 3:37 p.m. EDT (1937 UTC) across Ohio, West Virginia and small portions of neighboring states, warning of the extreme wind threat.[7]It crossed over the Columbus area at approximately 5:00 p.m. EDT, with winds reported to 82 mph (132 km/h) there, and caused severe damage to the power grid in Franklin, Delaware, and Licking Counties. Winds were in excess of 80 mph (128 km/h) as well reported at many other locations across the state.[1] It maintained its intensity as it reached the Ohio River early in the evening, and the only reported (but unconfirmed) tornado associated with the system occurred in association with the derecho's bookend vortex, and did minimal damage in comparison near Newcomerstown, Ohio, at 6:20 p.m. EDT.[1] As the derecho reached the Ohio-West Virginia border, the SPC issued another severe thunderstorm watch at 6:35 p.m. EDT (2235 UTC), also with high wind probabilities, for the remainder of West Virginia, much of Virginia and Maryland, parts of Kentucky and Pennsylvania, and the District of Columbia.[8] The derecho crossed the mountains of West Virginia, leaving destruction in its wake, as well as parts of southwestern Pennsylvania and eastern Kentucky through the early evening hours.[citation needed]

File:Lighting over dc.tiff
Lightning strike over Washington, D.C.

The derecho continues into the night

Despite the mountainous terrain and loss of daytime heating, the hot, humid air mass and high instability allowed the storms to maintain their high intensity throughout, even though the amount of convective energy decreased slightly (to a still-extreme 3,500 J/kg).[9] They emerged into Virginia and Maryland later in the evening, where an even more unstable air mass awaited with CAPE values as high as 5,500 J/kg.[citation needed] As the derecho failed to weaken over the mountains, the moderate risk was expanded eastward by the SPC at 9:00 p.m. EDT (0100 UTC) into the mid-Atlantic region.[10] At 10:10 p.m., the SPC issued the final severe thunderstorm watch for the derecho for all of Delaware, the remainder of Maryland, the remainder of eastern Virginia, southern New Jersey, the Chesapeake Bay, and the Mid-Atlantic coastal waters.[11] The derecho continued to expand as it crossed the Mid-Atlantic states late in the evening, impacting nearly all of Maryland, Virginia, and Washington, D.C. The most severe winds—reported as high as 87 mph (140 km/h)—were focused in the Baltimore-Washington metropolitan area and southward towards Richmond. Widespread wind gusts over 70 mph (112 km/h), with some significantly higher, were reported across the large and heavily populated region.[1]

File:Derecho-radar-max.png
Maximum radar reflectivities over the entire affected area. The heavy precipitation in Iowa and Illinois was largely caused by the second storm.

Overnight at sea and dissipation

The damaging winds continued eastward across the Chesapeake Bay towards the Atlantic Ocean, losing little strength despite the cooler marine layer.[12] The derecho emerged into the Atlantic Ocean shortly before 2:00 a.m. EDT (0600 UTC) on June 30, while still producing winds as high as 81 mph (130 km/h) right at the coast in New Jersey and strong and damaging winds on the Delmarva Peninsula.[1] Numerous special marine warnings were issued for the coastal waters of affected states by the NWS as the derecho moved out to sea.[13] The storm dissipated around 4:00 AM over the Atlantic south of Long Island, New York[citation needed]

Second storm tries to develop

As the derecho moved through Ohio, a second storm developed in Iowa and tracked into northern Illinois. The derecho had used up most of the convective energy in the atmosphere, so this second storm did not become another derecho. Nonetheless, a small MCS with a bow echo developed and became severe as it moved along this track. Its formation prompted the SPC to issue another severe thunderstorm watch, the second of the day for much of the region, for the areas in its path including parts of Iowa and Illinois.[14] However, the storm reached the cold pool left behind by the derecho, and dissipated in the cool, weakly unstable air. Along its much shorter track, the second storm produced a maximum wind gust of 90 mph (145 km/h) in Marengo, Iowa. This second storm was responsible for the majority of the warnings issued and damage done west of the Chicago area during the event.[citation needed]

Impacts

Damage was widespread and extensive along the entire path of the derecho, especially in northern Indiana, central and western Ohio, northeastern Kentucky, southwestern Pennsylvania, West Virginia, northern, central, and southwestern Virginia,[15] Maryland, Washington, D.C., Delaware and southern New Jersey. In all the mentioned areas, many trees were uprooted or snapped, roofs were damaged, tents deployed to sell fireworks leading up to the 4th of July Holiday were collapsed, and power outages were extensive, with over 3.7 million customers losing power as a result.[16] An Appalachian Power representative described the power outage as the worst the company had ever seen.[15] In total, 22 people were killed across seven states and the District of Columbia.[17] At least six and possibly seven of those deaths were in Virginia, all of them due to fallen trees.[15] Two of the deaths were in New Jersey, after two children were killed by falling trees at a campground at Parvin State Park, three deaths were reported in Maryland and one death was reported in Ohio after the storm.[18] The fact that it occurred in the midst of the record Summer 2012 North American heat wave made conditions especially problematic, particularly for seniors and vulnerable people. Scattered structural damage also occurred along the path of the derecho, from both falling trees and the winds themselves. Some of the damage included siding torn off houses, roofs removed from houses, businesses and apartment buildings, mobile homes heavily damaged, barns and garages destroyed and airplanes flipped.[1]


File:2012 derecho outages.png
AEP Ohio power outages caused by the derecho

Ohio

Over 1 million customers lost power in Ohio, with power outages widespread across roughly two-thirds of the state. Saturday afternoon, Ohio Governor John Kasich declared a state of emergency due to widespread power loss, damages, and the ongoing heat wave.[19][20] On Sunday afternoon, President Obama declared Ohio a federal disaster area, allowing FEMA money and resources to be used in the area.[21] The storm was more damaging to the power grid and more severe in terms of wind gusts than Tropical Storm Ike, which hit the area in September 2008 with 60 mph (97 km/h) sustained winds and 80 mph (130 km/h) gusts after slightly re-intensifying over Indiana, making it both the largest power outage and the largest power outage not related to a hurricane in AEP Ohio history. Wind gusts with this derecho were closer to 85 mph (137 km/h), and, though of a significantly shorter duration, caused more damage to trees and power lines than Ike.[22] In fact, this derecho was so destructive that Accuweather compared its destruction to that of Hurricane Irene, and The Weather Channel compared it to hurricane damage in general.[23]

File:Derecho-crushed-car.jpg
Crushed car and downed tree in Huntington, West Virginia

West Virginia

In West Virginia, about 672,000 customers lost electricity.[24] Governor Earl Ray Tomblin of West Virginia declared a state of emergency after the storm. All but two of the state's 55 counties sustained some damage or loss of power. At peak, more than half of the state's customers were without power. Around 70 high voltage power lines were downed.[25] The derecho's aftermath was arguably more difficult in West Virginia than anywhere else. Power restoration was very slow and outages extremely long, as a result of the sparse and scattered population, mountainous terrain, difficult conditions in extreme heat and need for crews over a large area. The American Red Cross shipped tens of thousands of meals to the state, along with large quantities of water to residents in entire communities that were isolated as a result.[26]

The derecho's bookend vortex near Pittsburgh, Pennsylvania

Pennsylvania

Across Pennsylvania, 32,500 customers lost power.[16] Storm debris delayed trains at 30th Street Station in Philadelphia.[27]

File:Virginia-derecho-damage.jpg
Downed tree in Fairfax, Virginia

Virginia

About 1 million customers lost power in Virginia, which was the largest outage in the state's history not related to a hurricane, and third largest outage including hurricanes, after Hurricane Isabel in 2003 and Hurricane Irene in 2011.[28] The outages also affected the Amazon Elastic Compute Cloud datacenter in northern Virginia, which caused Instagram, Pinterest, and Netflix to experience significant outages.[29] In Franklin County, Virginia, southeast of Roanoke, a volunteer firefighter was killed by a falling tree while responding to an emergency.[15] Two people in Big Island were killed in a storm-related house fire during the night of June 29[30] In the Roanoke Valley area, upwards of 65,000 residents in Roanoke, Lynchburg, and Danville lost power.[15] Governor Bob McDonnell of Virginia declared a state of emergency after the storm.[31]

Tree and power lines down in Washington, DC

Washington, D.C., and Maryland

The storm left about 68,000 customers without power in Washington, D.C., and in Maryland, there were about 900,000 customers without power, including some in each of the state's counties.[16] Water restrictions were also in place afterward in Montgomery County and Prince George's County in Maryland after the water supplies in those heavily populated suburban counties lost power. A Washington, D.C., man was shocked to death and his wife critically injured when they went outside to check the damage to their house from a fallen tree.[32] The AT&T National golf tournament at Congressional Country Club was also slowed due to severe tree damage on the course.[19] Governor Martin O'Malley of Maryland declared a state of emergency after the storm. As of July 6th, over 4800 tons of storm debris had been collected in Montgomery County, Maryland, with collection ongoing.[33]


Downed tree in Ocean City, New Jersey

New Jersey

In South Jersey, Atlantic City Electric reported that 206,000 customers lost power from downed trees. Most of the outages were in Atlantic County, which prompted a county-wide state of emergency. Near Atlantic City, a boater died while trying to bring his vessel ashore. Officials believed that lightning struck a 104-year-old church in Longport and caused a fire that damaged the building.[34] An elderly couple was killed when a tree fell on their house. In Vineland, damage was preliminarily estimated at $125 million.[35]

See also

References

  1. ^ a b c d e f "120629's Storm Reports (1200 UTC - 1159 UTC)". Storm Prediction Center. National Oceanic and Atmospheric Administration. June 29, 2012. Retrieved June 30, 2012.
  2. ^ "Downburst Crosses KLOT Doppler Radar 6/29/2012". National Weather Service. June 30, 2012. Retrieved July 5, 2012. {{cite web}}: Check |url= value (help)
  3. ^ http://mesonet.agron.iastate.edu/vtec/#2012-O-NEW-KIWX-EH-W-0001/USCOMP-N0Q-201206281500
  4. ^ Racy (June 29, 2012). "Severe Thunderstorm Watch 435". Storm Prediction Center. National Oceanic and Atmospheric Administration. Retrieved June 30, 2012.
  5. ^ Pydynowski, Kristina (June 30, 2012). "Deadly Super Derecho Strikes Midwest, Mid-Atlantic". AccuWeather. Retrieved June 30, 2012.
  6. ^ Thompson (June 29, 2012). "Severe Thunderstorm Watch 436". Storm Prediction Center. National Oceanic and Atmospheric Administration. Retrieved July 5, 2012.
  7. ^ Jewell (June 29, 2012). "Jun 29, 2012 2000 UTC Day 1 Convective Outlook". Storm Prediction Center. National Oceanic and Atmospheric Administration. Retrieved June 30, 2012.
  8. ^ Hart (June 29, 2012). "Severe Thunderstorm Watch 438". Storm Prediction Center. National Oceanic and Atmospheric Administration. Retrieved July 5, 2012.
  9. ^ Goss (June 29, 2012). "Mesoscale Discussion 1314". Storm Prediction Center. National Oceanic and Atmospheric Administration. Retrieved June 30, 2012.
  10. ^ Edwards (June 30, 2012). "Jun 30, 2012 0100 UTC Day 1 Convective Outlook". Storm Prediction Center. National Oceanic and Atmospheric Administration. Retrieved June 30, 2012.
  11. ^ Goss (June 29, 2012). "Severe Thunderstorm Watch 439". Storm Prediction Center. National Oceanic and Atmospheric Administration. Retrieved July 5, 2012.
  12. ^ Goss (June 29, 2012). "Mesoscale Discussion 1316". Storm Prediction Center. National Oceanic and Atmospheric Administration. Retrieved June 30, 2012.
  13. ^ http://mesonet.agron.iastate.edu/lsr/#/201206290400/201206300900/0010
  14. ^ Thompson (June 29, 2012). "Severe Thunderstorm Watch 437". Storm Prediction Center. National Oceanic and Atmospheric Administration. Retrieved July 5, 2012.
  15. ^ a b c d e "Some in Roanoke could be without power until Saturday - wdbj7.com". WDBJ7.com. Roanoke, Virginia: WDBJ Television Inc. 30 June 2012. Retrieved 2 July 2012.
  16. ^ a b c Ian Simpson (2012-06-30). "Storms leave 3.4 million without power in eastern U.S." Chicago Tribune. Reuters. Retrieved 2012-06-30.
  17. ^ "Easy Fix Eludes Power Outage Problems In US". Associated Press. July 3, 2012. Retrieved July 3, 2012.
  18. ^ "States declare emergency after storms leave over a dozen dead and millions without power". Fox News. 1 July 2012. Retrieved 5 July 2012.
  19. ^ a b MSNBC staff (June 30, 2012). "Triple-digit temps as millions suffer storm power outages". MSNBC. NBC Universal. Retrieved June 30, 2012.
  20. ^ Bassu, Moni (June 30, 2012). "3 states declare emergencies as heat, deadly storms bring misery to millions". CNN. Retrieved June 30, 2012.
  21. ^ "President Obama Signs Ohio Disaster Declaration". The White House. 13 July 2011. Retrieved 5 July 2012.
  22. ^ http://www.bizjournals.com/columbus/news/2012/07/03/16-hour-days-more-workers-mark-aep.html
  23. ^ Jon Erdman and Stu Ostro (3 July 2012). "5 Extraordinary Derecho Events". The Weather Channel. Retrieved 5 July 2012.
  24. ^ "UPDATE 5-Storms leave 3.5 mln without power in eastern U.S." Chicago Tribune. Reuters. 30 June 2012. Retrieved 5 July 2012.
  25. ^ Hoppy Kercheval (2 July 2012). "Hoppy's Commentary on the Storm". MetroNews. Retrieved 5 July 2012.
  26. ^ Brian Todd; et al. (5 July 2012). "In West Virginia, mass feedings planned in wake of storms, heat wave". CNN. Retrieved 5 July 2012. {{cite web}}: Explicit use of et al. in: |author= (help)
  27. ^ George Anastasia, Amy Rosenberg, and Linda Loyd (July 1, 2012). "Atlantic County hardest hit by storm". Philadelphia Inquirer. Retrieved July 5, 2012.{{cite web}}: CS1 maint: multiple names: authors list (link)
  28. ^ http://wtkr.com/2012/07/01/dominion-power-outages-third-largest-after-hurricanes-isabel-and-irene/
  29. ^ http://venturebeat.com/2012/06/29/amazon-outage-netflix-instagram-pinterest/
  30. ^ "Two people killed in Big Island as a result of Friday's Storm - wdbj7.com". WDBJ7.com. Roanoke, Virginia: WDBJ Television Inc. 30 June 2012. Retrieved 3 July 2012.
  31. ^ "Va. Gov. Issues State Of Emergency Declaration After Storm". CBS Local. June 30, 2012. Retrieved July 5, 2012.
  32. ^ D.C. storm 2012: Power out for thousands, nine killed in region, WJLA Retrieved June 30th, 2012.
  33. ^ Montgomery County collecting tons of storm debris, WTOP Retrieved July 6th, 2012.
  34. ^ George Anastasia; Amy Rosenberg; Jackie Urgo; Frank Kummer (2012-06-30). "Atlantic County hardest hit by storm". Philadelphia Inquirer. Retrieved 2012-06-30.
  35. ^ "Damage could top $100 million". The Daily Journal. 2012-07-03. Retrieved 2012-07-04.
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