2014-05-21 REPORTS: CO

[Hannah.Taylor]

Here's my question. A tornado was reported near Watkins at 2:45 by a county official. I am wondering if any of you saw anything that could confirm that. I sure thought there could have been something back in there, but there was just enough rain wrapping around near the ground that I could not tell and still can't after looking at the video (which will be posted and linked when I get my final report up).

Very interesting day and unusual to see an HP supercell like that in Colorado. Crazy chaser traffic on route 36, though; worst I've ever seen and probably the worst that has ever happened in Colorado.

i dont want to speak for anyone but I thought i saw Verne Carlson was on that storm and had definitive tornado pic on facebook, with dust/debris in the field below the funnel. I also saw other confirmations from fb on cbs 4 denver 9 denver news fb like pages of the watkins storm producing a tornado

also ive seen worse chaser convergence, last year in Moore and a few days earlier on the Brownell, KS storm as it tracked north and east towards Hayes, KS.

the thing im curious is there were reportedly 9 tornado touchdowns, however only the watkins one appears to have any credibility.

http://www.denverpost.com/weatherne...t-range-storm-lacked-actual-tornadoes-experts

I have to question the rain-wrapped multi-vortex tornado report because typically Denver are storms dont produce strong tornadoes let alone multi-vortex. the last notable strong tornado in the area was the May 22, 2008 Windsor tornado.

 

[John Farley]

Verne's was the one near Byers, which I missed as I was battling the chaser traffic on 36 at the time. I have seen video of the one near DIA, no doubt that was legit so there were at least 2. But I've seen no confirmation on Watkins. Edit: Since I made this post, I did find some video from Channel 7 in Denver showing what they said was dust being lifted under the wall cloud near Watkins, so maybe. Pretty jumpy video though, so still a little hard to tell for sure.

 

[Tim Carley]

This was my first time chasing the DCVZ and I enjoyed it. The convergence was actually pretty orderly. These are from both days.

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[Michael Snyder]

Like gazillions of the rest of you, I was on the big HP supercell that formed over Denver. Tracked it from just east of Aurora until it lined out near Last Chance. I will get a full report up in the next few days as time permits, but in the meantime here are a few pictures and a question.

The first pic shows the rain-wrapped circulation that produced the tornado near DIA around 2:30. I was a little too far south to see the tornado through the rain, because I initially positioned for the cell that formed in the southwest suburbs.

The next two pictures are of a large rotating wall cloud near Watkins around 2:45. In the first picture, the feature was just north of Watkins:

When I took this one the storm and I had both moved a little east. The rotation was northeast of Watkins now.

Here's my question. A tornado was reported near Watkins at 2:45 by a county official. I am wondering if any of you saw anything that could confirm that. I sure thought there could have been something back in there, but there was just enough rain wrapping around near the ground that I could not tell and still can't after looking at the video (which will be posted and linked when I get my final report up).

Very interesting day and unusual to see an HP supercell like that in Colorado. Crazy chaser traffic on route 36, though; worst I've ever seen and probably the worst that has ever happened in Colorado.

I had to really mess with the contrast to get the meger funnel to show up, but yea this was right around 2:45pm...

 

[Hannah.Taylor]

Verne's was the one near Byers, which I missed as I was battling the chaser traffic on 36 at the time. I have seen video of the one near DIA, no doubt that was legit so there were at least 2. But I've seen no confirmation on Watkins. Edit: Since I made this post, I did find some video from Channel 7 in Denver showing what they said was dust being lifted under the wall cloud near Watkins, so maybe. Pretty jumpy video though, so still a little hard to tell for sure.

you are correct. my mistake.

 

[Dan Robinson]

I have some more work to do with processing imagery of this trip, but for now the video and a few images are up on my Youtube/Facebook accounts:

Video from May 21-22:
https://www.youtube.com/watch?v=bf7ZxJuQWoY

Chaser convergence timelapse on May 21 near Byers:
https://www.youtube.com/watch?v=Xmx7k_l5XNI

Some temporary images posted:
https://www.facebook.com/stormhighwaycom

GPS track:
http://stormhighway.com/2014/may20-23.php



Chase Account: After overnighting in Salina, I arrived on the Denver storm of the day as it was moving out of Aurora. I watched it approach along 25th, then parked 1m south of 26th and 88th just east of DIA, just northeast of the approaching notch to try and get a glimpse of what might be lurking inside. I got a very low-contrast and questionable look what may have been the reported tornado. Until I can get some detailed locations and times, I'm not inclined to 'count' it just yet.

I left this location about 30 seconds too late, as the hail core northeast of the meso gave me a glancing blow - and two spider cracks in the windshield - as I moved east on 88th.

The storm appeared to cycle again northwest of Byers with a strong RFD cut slicing 3/4 of the way around a conical-shaped wall cloud, but motion in this feature was rather weak.

The storm again cycled northeast of Byers with surging RFD, but I was forced south to US 36 and out of optimal position in order to access what appeared to be the only bridge across a north-south creek. Once pulling onto 36 eastbound, I hit massive chaser convergence, with a long slow-moving line of traffic and dozens if not 100 vehicles parked along the road (see the timelapse linked above). For this reason I opted to continue far ahead of the storm to re-position on gravel roads and thus avoid the crowds. The storm unfortunately began merging with cells to the south at this point, ending the chase. I headed back to Aurora to spend the night.

 

[StephenHenry]

Same storm as everyone else. Not much to add other than, DANG, did the HRRR nail this one in terms of timing, placement, and death of the big HP supercell. HRRR has been on fire lately. Approaching from the south, we were initially about 10 minutes late getting into Denver and had to divert off the interstate as the storm moved through the metro. Finally got out in front of it as it barreled down I-70. Beautiful chase country and some really excellent timelapse opportunities, even if we couldn't ever see any of the reported tornadoes. Also had a David Hoadley sighting on a dirt road north of Byers, but I was too shy to go up and say hello All in all, an incredibly fun chase!

Watch video >

 

[John Farley]

I now have my full chase log posted, along with lots of photos and some video clips, at:

http://www.johnefarley.com/chase52114.htm

 

[Scott Sims]

Sorry for the delay, I was lazy on video processing this week. Now that a new system and many days are on the way, I had to clear out the SD cards and process last week's adventures.

Most everyone knows or has read the whole setup with the Denver Cyclone and the HRRR nailing yet another cell. So, to make it short, my video is a timelapse of my personal best views of the storm(and a few chaser convergence points). Most of the sections are 16x timelapse, but a couple segments are 20x. The footage starts near Watkins,CO and follows the cell off and on for about 3 hours.

Watch video >

 

[Skip Talbot]

Jennifer Brindley Ubl and I stayed up in the inflow notch north of the Denver airport and then cut north through the forward flanking precipitation as the storm was engulfed in an MCS before coming back down to rescue Brad Goddard who had gotten stuck in the mud. Photogenic HP supercell but we didn't observe anything tornadic from our position. Full log, photos, stats, and annotated map:

http://skip.cc/chase/140521/

 

[cdcollura]

Good day all,

Better late than never ... Below is my chase log for May 21, 2014 in Colorado from near and east of the Denver area.

Summary: May 21 was to be the greatest chance at seeing tornadoes (out of my chase trip from May 19-22), and a trip to NE Colorado was part of the days plan. I forecasted and found the best area anywhere from north of Denver, Colorado and points eastward. The SPC had this area in a slight risk outlook, with a 10% tornado, 15% wind, and 30% (hatched) hail probabilities for an area bulls-eyed just north and east of Denver. I left Ogallalla, Nebraska and headed west on I-80 then I-76, reaching Brighton, Colorado by noon local time. This area seemed to be the place to be, and storms began initiating near Golden, Colorado / Denver to the SW. This storm was the main tornadic supercell of the day, and was tracked from near Denver International Airport and eastward along Bromley Lane to Highway 79 south (and along farm roads), eventually winding up heading east on Highway 36. The chase ended on Highway 71 north of Last Chance, Colorado. After I was done chasing, I headed back along Highway 36, taking a detour to the hail swath and flooding to the north of Byers, then resumed west on Highway 36 to I-70, and west into the city, and south on I-255 for the night in Aurora.

Above: In the graphic above, the SPC tornado outlook of 10% is shown in the left image, bulls-eyed over NE Colorado. This area was in a slight risk outlook, with an additional 15% wind and 30% (hatched) hail probability. In the middle image, the mesoscale discussion (MCD 636) is shown, with the greatest tornado threat near the Palmer Divide east of Denver, and a lesser threat area extending into Wyoming due to upslope wind flow and an outflow boundary. Despite tornadic storms forming east of Denver that day, another tornado developed well to the north near Chugwater, Wyoming (just north of the 2% outlook on the left image in Wyoming). The right image is the incredible NWS radar (base reflectivity) presentation of the tornadic supercell moving across Denver and Arapahoe Counties, and over Denver International Airport, during the late afternoon. The "hole" of the radar image is the "cone of silence" directly above the radar antenna, which cannot "look" straight up. The actual tornado, if any, is rain wrapped and should be just west (left) of the cone of silence "hole".

Above: Heading east out of Brighton with an incredible radar presentation of the storm on my screen!

Above: Funnel cloud / possible firsrt tornado from the supercell over Denver International Airport (reported near Towers road).

Above: Hail fall covers ground with some stones up to 2 inches near Commerce City, Colorado just west of Denver International Airport.

Above: The melting hail and passage of a tornadic HP supercell leaves its mark on the landscape. This caused a massive hail fall and flash flooding north of Byers, Colorado.

Above: From Highway 36 near Byers, Colorado ... The hail "swath" is pretty ominous 2-3 hours after an HP supercell dumped nearly a half foot of hail on the landscape!

Full report on this storm (May 21, 4:00 PM): Observation and indirect penetration of an extremely severe and tornadic thunderstorm in Adams County, Colorado from near I-76 and Brighton and eastward past Denver International Airport, and finally into Bennett and Byers along Highway 36. The storm was an HP supercell with violent rotation. A very large wall cloud and some small tornadoes were observed with this storm. The storm became outflow dominant and merged with a line segment during the end of its lifecycle north of Byers. Large hail was observed with this storm, with some pieces near 2" (the core had at least 3"). 70 MPH winds, frequent lightning, and heavy rains were also encountered with this storm. The hail left a large area with significant accumulations and flash flooding was observed in rural areas after passage of the supercell. Conditions causing the storms were surface heating, a low pressure trough, upper trough, and upslope wind flow. A 2009 Ford Escape was used to chase the storms. Documentation was digital stills and HD video. A tornado watch was also valid for the area until 8 PM MDT.