Tornadic storms have plagued the Denver metro area for the last several days. I worked as an embeded severe weather reporter, traveling with Colt Forney and Lauren Hill Forney, Weather Adventures, Basehunters, and iTornado Experience following tornadic supercells on May 21, 2014 in the Denver metro area.
The Storm Prediction Center (SPC) issued a 10% tornado risk for the Front Range of Colorado on May 21st. We now know that was an excellent call, as a massively powerful tornadic mesocyclone struck Denver International Airport (DIA) in the afternoon of May 21st.
We originally positioned our storm track vehicle at the intersection of I-70 and Gun Club Road, near the off ramp to Denver International Airport. We tracked the tornadic storm as it built over Denver, in an eerie fashion, as it had done the same thing just one day before on May 20th, 2014 (See slideshow).
We first saw the tornado wall cloud to our southwest, as the powerful storm had fired up near Evergreen, Colorado, moved across south Denver, getting larger and crossing I70 at our location, and then heading in a path directly for DIA (See slideshow).
The mesocyclone continued to strengthen as is passed our position. We saw strong rotation in the tornado wall cloud as it passed, briefly possibly seeing a rain wrapped tornado (See picture). Tornado sirens were blaring behind us and ahead of us, as well. We were also getting messages, on our cell phones, due to our GPS position,warning us of an imminently dangerous tornado threat for our area, that advised, "if you are in a home, seek shelter immediately." This is a welcome change, and shows the power of NWS working with cell phone companies and social media to provide critical precise warnings to smart phone users, based on their present location.
Next, the skies darkened overhead, almost immediately. We went from afternoon bright sun daylight, to near dark night like conditions where we turned on our headlights to drive, in less than 5 minutes, after the storm passed us to the northwest.
We were in contact with other storm trackers and scientists, as well. I was informed that the Center for Severe Weather Research (CSWR) was tracking the powerful mesocyclone with mobile Doppler radar, and that they were heading our direction. We were also in contact with other storm trackers, and since we had the most forward position on the storm, at that time, we were providing 'on scene' reports to other chasers about the strength of the tornadic couplet that passed across the highway in front of us. We met up in the field with Tim Marshall, Rutger Boonstra, Paul Robinson, Dr. Karen Kosiba, Dr. Josh Wurman CSWR, Roger Hill, Silver Lining storm tours, Dave Holder, Weather Adventures, Scott Peake, Basehunters Chasing, Jeff Piotrowski, and many other notable tornado storm trackers from States in tornado alley.
It was scary when the skies went dark and the tornado sirens just stopped and went silent. We then heard tornado sirens in the distance near DIA. We watched with foreboding as the now powerful tornado mesocyclone velocity was heading straight for the airport.
We then began to track the tornado as it passed through DIA and moved on a near eastward track just north of highway 36th. We were getting some sketchy damage reports from DIA at the time, indicating that Frontier Airlines had more than a dozen damaged jets. It was later that we found out this damage was from wind driven hail. There were reports of power flashes near DIA when the storm passed overhead, and NEWS7 had pictures of broken and downed power poles.
As we kept pace with the powerful tornadic storm, traveling eastward on HWY 36, we marveled at the near perfect tornadic hook on base reflectivity and base velocity scans, indicating a near perfect mesocyclone had formed and was tracking right through DIA. We did briefly see a rain wrapped tornado, and a lesser elephant trunk tornado that had formed from a new flanking line of cumulus towers that fed into a newly developing occlusion as the older mesocyclone evolved. The tornadic storm briefly back built as it tracked eastward, indicating influence of upslope conditions and possible formation of the Denver Cyclone system or Denver Convective Vorticity Zone (DCVZ). Massive amounts of hail also fell over DIA when the core of the storm passed overhead.
Jennifer Casey, television producer, and tornado chaser Sean Casey's wife, took pictures of the stacked plates of the meso cyclone hitting DIA from her vantage point within the hanger before she evacuated to a tornado shelter. That image went viral immediately over social media like FB and Twitter.
There were more tornadoes this morning, as well. One tornado, a fairly strong one was present high in the mountains near Red Feather Lake. We took pictures of brief mountain tornadoes between Boulder and Lyons today.
Many people were commenting on the strength of the DIA tornadic supercell, stating that kind of storm hits in Oklahoma and Texas, but is not common along the Front Range of Colorado. From an interview with a local Colorado storm chaser to get his perspective, he said, "many large mesocyclone driven tornadoes do occur in Colorado but are rarely noticed, as they more often form in the eastern planes of the state were there is mostly open range land. It is a myth that meso cyclone tornadoes don't hit Colorado, or that tornadoes don't form in the mountains either. In Colorado, we get both."
This is the second year in a row that Denver International Airport has been hit by a powerful tornadic storm. DIA emergency management worked efficiently getting nearly everyone in the airport into tornado shelters before the storm struck the concourse areas. Many people were surprised and relieved at how efficiently DIA management got people to safety before the storm struck. There were no injuries reported from this tornadic storm at DIA, and airport operations resumed as normal after snow removal crews cleared deep hail off the runways.