More than a week after a fast-moving storm was torn by Austin, meteorologists confirmed that a microburst-a rare and intense downraft-behind was a large part of the destruction, with wind up to 85 mph in parts of the city.
The Supercell of 28 May, who quickly intensified about Austin during peak evening living work, shattered windows, overdoed trees and outdoors strength to tens of thousands. A new analysis that has been released this week causes the strip of damage and shows how cold air from melting hail -fed sudden, violent downbursts in several neighborhoods, according to the National Weather Service.
Area Prognast Discussions and Stormage Reports confirm that the Microburst formed as a different atmospheric systems that clashed in the center of Texas: a stalled front, a moist and unstable air mass and a dazzling bag of mid-level energy that is known as a mesos scale convortex. But it was the rapid cooling of hail up – damped dense air to the surface – that made the storm particularly dangerous.
More: Why did Austin come so hard and quickly? A collision of systems from Mexico to Colorado
A Storm's Anatomy: What made it different
A new 3D visualization of the internal structure of the storm illustrates the dynamic system that unfolded on 28 May between 6.30 pm and 7 pm. Two different Downraftzones were created during the peak of the storm:
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Back flank Downdraft: This zone moved across the center of Austin with winds from 55 to 75 mph, causing damage to high -voltage lines, companies and trees in the core of the city.
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Prey Flank Microburst: A stronger gust of wind went through the north, centrally and eastern Austin with gusts of wind that reached 85 mph. This was responsible for the majority of the damage, including downstairs limbs and structural failures.
Images of the National Weather Service Office show the path of the Supercell that caused widespread damage in Austin.
These powerful downdrafts were supercharged by cold air aloft, created as a hail melted and the surrounding atmosphere cooled. The cooled, dense air then rushed to the surface – a characteristic of a microburst event. Rainfall was also intense, with 2 to 3 centimeters in just 15 minutes in some parts of the city.
At 6:59 pm, according to the National Weather Service, a 77 MPH Windflagen was registered on Austin-Bergstrom International Airport.
How the Supercell moved across the center of Texas
Radar and satellite data show that the storm began to form just after 4.30 pm near San Saba and Burnet. Around 5:30 pm it was intensified and it quickly moved to the southeast by Bertram and Liberty Hill. The system reached full strength above Austin between 6:30 pm and 7:00 pm and then weakened somewhat when it continued in Bastrop County at 8 p.m.
Images of the National Weather Service Office show the path of the Supercell that caused widespread damage in Austin.
Radarreflectivity cards with high resolution show intense precipitation and hail nuclei while the storm moved. Overlaid Warning Polygons published by the National Weather Service show how predictors followed the growing intensity in real time, although even advanced models had difficulty predicting the sudden seriousness.
Destruction
A detailed damage card composed of 311 reports, radar scans, storm surveys and public entries emphasizes the impact zones of the storm:
Images of the National Weather Service Office show the path of the Supercell that caused widespread damage in Austin.
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Red zone (forward flank microburst): Cover large parts of North and East -Austin, where peak winds and destruction were concentrated.
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Yellow zone (rear downDraft): A slightly weaker path above the center, still capable of widespread damage, broken windows and uprooted trees.
The winds followed largely important transport corridors, including I-35, US-183 and FM 969, and emphasized how widespread and structured the damage path was.
This article originally appeared on Austin American-Statesman: Inside the Microburst who hit Austin, explained in 3 NWS images
