Thunderstorm Wind — Mason, West Virginia

2012-06-29 · near Point Pleasant, Mason, West Virginia

Event narrative

Numerous trees and large branches were blown down. Electricity was lost to about 13,700 customers. Three houses were destroyed, 5 had major damage, and 3 had minor damage. The public infrastructure damage assessment was around $160,000.

Wider weather episode

On the second day of a developing heat wave, under a sunny sky, afternoon temperatures reached record levels. The lowlands saw thermometers reach into the upper 90s and above 100 degrees. For example, both Huntington and Charleston had 103 degrees. Parkersburg and Clarksburg had 98 degrees. Even the mountainous regions reached into the 90s. Beckley and Elkins reached 96 degrees.

Meanwhile, an area of multi-cellular convection had moved out of northern Illinois that morning. It continued to organize and strengthen, as it propagated east and southeast across northern Indiana into western Ohio during the afternoon. As it moved toward southeast Ohio, it had already formed into a large arch of storms, or bow, with a developing cool pool in its wake. The temperature contrast between the air ahead of the developing derecho, compared to that in its wake was reaching 30 to 35 degrees. The resultant wind shift in the cool pool resulted in strong moisture convergence on the leading edge of the complex. This in turn, helped drive the storms further southeast, away from the mid and upper level wind support. However, the complex was diving right into that hot air that had obtained large convective available potential energy, or the order of 4000 to 5000 j/kg.

The complex streaked across southeast Ohio near the hottest time of the day and plowed into western West Virginia near 1730E. The outflow, or gust front, had outraced the rain, as it moved through southeast Ohio. That gust front then moved southeast at 60 to 65 mph across West Virginia. The mature derecho caused the strong gusts to be longer in duration than found in most severe thunderstorms. In some cases the strong wind gusts lasted around 10 minutes. Due to the dry ground, dust and debris accompanied the gust front in some areas. The storms and showers that followed the strong wind gusts only provided about a quarter to a half inch of rain. A few areas even had less rain.

Widespread wind gusts of 60 to 80 mph were likely with the leading gust front, before weakening in the southern coal fields of West Virginia. A few favored and exposed locations may have seen gusts around 90 mph. Locations sheltered from the northwest had gusts less than 60 mph. The strongest measured gust was 77 mph from the Charleston airport at 1810E. The Huntington airport had a gust to 59 mph at 1758E. The Clarksburg airport had a gust to 66 mph at 1828E. The Elkins airport had a gust to 64 mph at 1857E. The Beckley airport had a gust to 68 mph at 1907E. A spotter in Weston reported a gust to 73 mph on their private equipment. Likewise, a spotter in Mason County reported a gust to 62 mph.

The wind caused numerous trees and large branches to fall in scattered locations throughout most counties. Luckily, there were no direct deaths. There were 3 indirect deaths that followed from the storms. There was only one direct injury.

There was structural damage. Corrugated metal and siding were ripped off buildings. Trees fell onto houses or vehicles. Overall though, there was not a lot of physical damage to individual property. The fallen trees and power lines also caused roads to be temporarily blocked. However, the largest impact of the high winds was on the electric power grid. Prolong power outages occurred as the heat wave continued during the first week of July. The workers restoring the electricity had to take frequent breaks due to the heat and the safety equipment they had to wear. The electric utility companies had regional transmission lines damaged. These had to be repaired in addition to the usual distribution system. One electric company had to replace over 1000 poles, 575 transformers and 172 miles of wire. That total does include a few counties outside of West Virginia.

The lack of electricity in the midst of the heat wave, disrupted the daily routines of most citizens for several days. The word, derecho, was introduced into many everyday conversations. Water and ice were in high demand. Family and retail refrigerated food lost was substantial. An emergency declaration by President Obama allowed the federal government to quickly deliver nearly 300 truckloads of water and 750,000 meals. The federal government also shipped over 100 industrial sized generators for critical infrastructure use. Some people slept outside on porches where it was cooler. With limited gas stations available to pump gas, long lines developed for a few days in the wake of the storm. Phone and water service were also affected. Telephone companies had to use emergency generators to power cell towers. Likewise, water companies had to find power for their pumping stations. Citizens that relied on well water had no power to pump the water from their wells.

Around 600 state natural guard troops performed wellness checks, delivered food and water, and helped in clearing away the fallen trees.

Mainly due to the public damage, a federal major disaster was eventually declared for this episode. A few others episodes in early July were also included. See FEMA disaster number 4071 for more details.

View location on OpenStreetMap → (38.8500, -82.1200)

Source: NOAA Storm Events Database, event_id 394953. Narrative written by the NWS forecast office that issued the report.