Two complexes specifically have been liable for the lion’s share of the injury. They have been each arcing, bow-shaped strains that swept from west to east. The primary plowed from Washington County to Cecil County in northern Maryland late within the afternoon. The second blitzed Northern Virginia, the District and central Maryland through the night. Each introduced down scores of timber and wires — some on properties and vehicles.

D.C. area cleans up after heavy storm

A 3rd, considerably much less intense advanced tracked via north-central Virginia and Southern Maryland late within the night, abandoning scattered experiences of damaging winds and at the very least one occasion of flash flooding.

Altogether, the Nationwide Climate Service acquired about 150 experiences of harm from the three complexes. Pockets of hail additionally fashioned inside the storms, some as broad as half-dollars. PowerOutage.US reported greater than 70,000 outages nonetheless remained Wednesday afternoon, almost 24 hours after the storm — the bulk in northern Maryland.

All three of the complexes generated downward blasts of violent winds that slammed into the bottom and fanned outward. The Nationwide Climate Service acquired about 40 experiences of winds between 39 and 70 mph. Listed here are some the height gusts recorded:

• Centreville: 70 mph
• Leesburg: 62 mph
• Washington Dulles Worldwide Airport: 60 mph
• Quantico: 59 mph
• Reagan Nationwide Airport: 52 mph

Inside a one-county radius of Washington, concentrated areas of harm have been reported close to Chantilly, Olney, School Park and Bowie. Olney seemed to be hardest hit, the place timber broken as many as 20 properties, and a couple of half-dozen households have been displaced.

Injury was additionally in depth in School Park, the place one man was severely injured when a tree fell on a house. The Climate Service concluded that peak winds within the space reached 80 to 90 mph and that winds blew in a straight line, ruling out a twister.

“Straight line winds from thunderstorms can produce tornado-like injury,” the Climate Service wrote in a storm survey. “Yesterday night’s estimated winds in School Park are equal to that of a low-end EF1 twister.”

Phenomenal sundown boasts pink sky, lightning and rainbows — all of sudden

The storm that brought on the extreme wind injury in Olney and School Park is called a long-track bow echo. A bow echo, not like a supercell that’s organized round a rotating updraft, is energized by a robust downdraft present. The surge of intense downdraft wind causes the entrance of the storm line to arc outward, racing forward of the adjoining areas. Bow echoes incessantly journey at excessive speeds of at the very least 40 to 50 mph.

The radar picture beneath reveals that the bow originated over West Virginia, south of Romney, between three and four p.m., as was being monitored by the Climate Service’s Storm Prediction Middle. The Climate Service workplace in Sterling, Va., issued a steady string of extreme thunderstorm warnings forward of this storm all the way in which to the Chesapeake Bay.

The following determine reveals the storm at 5:30 p.m., because it approached Interstate 95. The arc form is unmistakable. The northern finish of the bow echo had developed right into a comma-head-like construction and should have contained a big vortex, as sometimes occurs in these sort of storms.

The sturdy downdraft outflow alongside the storm’s vanguard generated a menacing-appearing shelf cloud — the place moist air is lifted a number of hundred ft, then condenses right into a low cloud.

That northern comma head generated a robust downburst that affected the subdivision simply south of Olney city middle at 6 p.m. A zoom-in of the cell is proven within the subsequent determine. The echo mass of heavy rain on the northern finish of the bow is proven within the left panel. The suitable panel is Doppler velocity and divulges air currents hidden within the rain.

The white circle encloses the realm impacted by the downburst, however probably the most excessive winds have been contained within the subregion of pink colours, simply southwest of Olney. That is sturdy circulate away from the radar, towards the northeast. The inexperienced adjoining area represents sturdy circulate towards the southwest.

Taken collectively, these two patches signify strongly diverging airflow. The premise right here is that an intense downdraft core struck the floor at an affect level proven by the white “X.” White arrows present the bidirectional outflow from the purpose of affect. Winds within the pink area will need to have generated winds of at the very least 60 mph, in all probability stronger, given the dimensions of timber that have been felled.

Many individuals hear a sudden roaring sound because the wind quickly accelerates to excessive speeds throughout a downburst. After the storm, the diploma of tree injury can appear unbelievable. Primarily based on the extent of harm and the roar, many assume a twister has occurred. However just like the scenario in School Park, the radar signifies a diverging, straight-line wind sample, somewhat than the rotary signature that will be related to a twister.

Because the bow echo approached, the ominous shelf cloud was a sight to behold. We acquired dozens of photographs of the cloud from readers and share a pattern beneath: