Tornado Me Once, Shame On You; Tornado Me Five Times ..."Slight Risk"

I think we will probably see a tornado warning in Northeast Colorado today. I think that there will be a couple reports of funnel clouds and possibly a brief, weak tornado. What has me wondering is why all of the sudden, SPC has a bull's eye over Northeast Colorado when the days previous have actually looked *better* for the likelihood of tornadoes than today does.

Is this a .. "wow, I guess we've been missing that, better bump up the probabilities to cover our ... etc" ? OR are they seeing something that I am not? I don't claim to be a better forecaster than the well-paid folks down in Norman, but it is difficult to forecast nationally, on the mesoscale. I understand that and am not writing some exposé here. Hell, I look at SPC every day and take their forecasts into account (unlike other folks who say they don't look at it and then post the probs in their blog every other day). lol I just find it odd that on a day that looks less intriguing than things have in this area all week, half the chaser community is abuzz with "Northeast Colorado."

I chose to sleep in today ... so I won't be able to get out of work early ... so I probably won't chase anything today unless it happens tonight ... but that is unlikely considering I have an appointment after work anyway. Granted, I'll probably miss a nice tornado (that would serve me right for even writing this), but I just don't see today being any more interesting than every day for this past week.

Anyway, I'm saving my money and time for this weekend. If you ask me, things will be *VERY* interesting on Saturday and especially Sunday. The upper level pattern is fairly static at the moment and should remain that way in the short term. Some energy will be coming through this weekend, however. We look to have 100mb of upslope moisture on both days and the hodos look great to turn some towers (more so than we've seen here recently). The models have been waffling a bit on the days, but there's enough there to really keep my attention as time unfolds.

So, if you're going out today, good luck. I'm ready to eat my words and hope things turn out better than I see them! I'll see you all this weekend!

DC

June 9th, 2009 Storm Chase Teaser

I wasn't even going to chase today ...

... but I got off work at 4PM, hit 225 (which was a mess as usual) and saw some ... "interesting" structure to my north. I needed gas, so I stopped and got some and then looked at the radar, seeing a nice cell forming on the north side of the Metro. I got on Peña Boulevard and then northbound on Tower Road when it went tornado-warned. I had a great view the entire time, though I did not see the funnel that prompted the warning. I did see several needle funnels in the scud which was rotating at a moderate pace along the skirt of the wall cloud. Family members in Thornton reported the sky "swirling overhead" also at the time.

Someone reported a tornado 4NW Firestone at 231Z which boggles my mind as 4NW Firestone was deep in a core at 2311Z. I would love to see more info on that one.

I followed the storms north on I76 and then north on Kersey Road to US 34. I saw a couple instances of lowerings and rotation, but everything became a convective mess. I headed east to Wiggins to get a better view and then saw a bit of convection on the southeast horizon, so I continued on I-76 to Brush, where I headed south. I was about to call it a day and head back to Denver, but the convection to my southeast was continuing to look robust, so I drove east on 36.

Outflow from the northern storms blasted south, creating some interesting cloud-deck turbulence in its wake. I was surprised by some rain drops so I pulled over to the side of the road. Looking back west, I watched the evolution of an elevated low-precipitation supercell with a gorgeous, sculpted mesocyclone. The meso even produced a short-lived, almost horizontal funnel cloud. (seen in the pics below)



I knew that this storm had no chance given that the air at the surface was COLD and not inflow ... it was obvious that the storm's base was elevated and had no connection to the surface. This was true of another storm further to the east (seen below).

I continued south on CO 59 and cored a new severe cell (from the robust convection I noted earlier) just north of Seibert. It contained (at least) 0.88" hail in the main core and possibly 1" hail on the outskirts of the rear flank. I stayed ahead of the storm on I-70 (eastbound), periodically stopping to try and take some pictures. Nothing really turned out and I was unable to detect any significant structure to the severe storm.

After some dinner in Burlington (the storm had weakened), I started to head home. Lightning in front of me prompted me to check radar and I saw a new cell developing just east of Limon. I intercepted the cell at Arriba (I drove south a mile or two on dirt for a better vantage). The rear flank gusted out, creating a nice shelf cloud. When it arrived, it contained wind-driven 1" hail. I called this one in.

0510

100

ARRIBA

LINCOLN

CO

3928

10327

(BOU)

The Weather Service was VERY CURIOUS as to whether I saw any rotation in the storm. I don't chase with data (except for my phone), so I was a little blind. I didn't see any rotation ... just the RFD shelf.

Passed another (eventually severe) cell near Limon and then headed home.

Not a bad day. Intercepted a tornado-warned storm, two severe-warned storms ... saw (at least) three funnel clouds, a nice LP-sculpted meso, had 1" hail twice, and the lightning was great as always.

Sounds like a lot more fun than was had in Kansas today!

Many thanks to Jonathan Splitt for nowcasting me through supercells after dark. :)

Dann.

June 7th Chase Teaser - Elbert County Tornado

Got an early start to chasing today. After seeing a huge tower go up, I moved to intercept east of the city. Met up with Cameron Redwine and we watched the storm become strengthen and weaken, etc. Suddenly, I get a call from my cousin Brian Macumber saying he's seeing a tornado looking north from 120th and Huron in Westminster. I figured it was a landspout, but the photos (taken from his phone) don't necessarily show a landspout.

We decided to keep on our storm until reports started coming in of tornadoes on the SOUTH side of the city. We hauled ass back toward the Metro while more and more calls and texts were coming in reporting a tornado in Aurora and damage. We finally could see the base as we blew eastward on US 36 and I observed a funnel for a good long while. Still not sure if it produced as we were not close enough. As we reached Byers and headed south, a new funnel formed and it actually touched at 2:34PM MDT.

Pic of the tornado (debris cloud was present but not apparent in the photo)
Vid cap a few minutes later. Debris faintly visible. (I was trying to drive and use the camera at the same time ... with a TON of bug guts on the wind shield.)






Map of the chase.

Also, I believe we were present for the 5S Deer Trail tornado. The storm became outflow-dominant and had a terrific shelf cloud. We decided to get back out in front of it and have a look and saw a two separate circulations on the edge of the shelf. There was violent motion present and a ton of dust on the ground. I didn't actually see the dust on the ground circulating, though. However, there was a column of dust present that stayed in the same place for a while and I did see a funnel cloud up in the raggedy edge. The vid cap below is horrible and I'm a little frustrated with the fact that the video "begins" when I thought I had just finished recording. So, this brief funnel is followed by five minutes of my front seat. Bah! Anyway, not enough proof in my opinion for a tornado, so I'm not counting it. (Cameron and company also bore witness to this funnel. I'm hoping they have a better photo/video!)




All in all, a somewhat frustrating, but good day. Why should I be frustrated? Well, I lost at least two videos due to either not hitting record or screwing something up ... my window was all buggy and that made videography difficult, I got tons of texts/calls from people seeing tornadoes all over Denver, and I had an awful headache. I did get to document one tornado, so I shouldn't be whining. It was just a long day!

Dann

June 4th Chase Teaser

Another lovely, back yard chase today.

Quick synopsis:

Both RUC and NAM kept the plains pretty well capped, but we had a great instability axis along and east of the Front Range. The lower level winds never really worked out well for us, but storms did take advantage of the insane lapse rates and fired especially off of the Palmer. Aside from getting pulled over (thank you Colorado State Patrolman for not giving me a ticket even though I deserved one), we were able to make it on some tough roads to CO 86 in time to see what seemed like a "left split" storm off of the main cell. This one had an updraft on its northeast side ... we were to the northwest and had a perfect view. You can see it in the first image below. To make a long story short, another storm formed to our north and took up a similar profile. Very odd storm orientation. Anyway, I had to gas up in Limon, so we decided to head up CO 71 to intercept the second storm which slowly died as it approached. All in all, a fun chase though ... got some very interesting structure.

Chase partner today was Jason Burns.

Interesting updraft on the northeast corner of the storm. This tower was rotating and at times, had a nice wall cloud. It reminded me of the Alta Vista tornadic storm last year, though almost in a "mirror universe".

Looking west to the second intercept. Again, updraft on the north side of the storm, low, and rotating.


Did a little four-wheelin' on cake batter near Cedar Point.

Sunset colors near the old Aurora Airpark.

Alta Vista comparison. (Left: Alta Vista tornadic LP supercell, looking NW; Right: Today's storm, looking to the east.)



Radar of our first storm. Note the "hook" on the NW side.

The second storm (north of the warning) at its peak intensity.

All in all, a fun day ... and tomorrow looks better!

Dann.

Radar imagery used with permission (IPS Meteostar)

May 31st Chase Teaser

Quick back yard chase today ended up being a little longer than I had intended, but it paid off in the end with a great light show on the Palmer Divide after dark. The day didn't exactly go along with my forecast, but at this rate, I'm not going to complain.

Very awesome and coincidental to meet up with Cameron Redwine and Scott Landolt at Cedar Point while trying to view some lightning. It's a small chase world after all!

Strong storm firing just east of the Denver-Metro area.

Interesting updraft structure (south of Strasburg).

The Kiowa water tower with mammatus.
Amazing shelf cloud (or possibly rotational structure) east of Matheson, Colorado.

Lightning fun north of Matheson.

And time to leave!

Thanks to Michael Carlson and Johnathan Skinner for nowcasting!!

May 30th Chase Teaser

Had a great little back yard chase today with Michael Carlson. My initial target was a my forecast convergence zone east of DIA. By the time we got out, convection was already firing on a boundary further east. Secondary target for the day was the Limon area as the vertical shear would be better. The convergence east of the airport wasn't that great, so we headed to Last Chance and then south to intercept some stronger cells. (first photo) We got on one that had been sitting for a while and mineswept the hailcore, finding mostly 1" stones. The rear-flank pushed them out hard, driving them in horizontally to the driver's side (Michael found a couple new dents ... from only 1" hail!) A way down the road, we found some bigger (1.25") that had already fallen. The storm also had a nice, tight circulation in the updraft (second photo). It soon died, though and we tried to intercept others, but the whole area lifted and we lost definitive cells. We pretty much called it a night at that point.

(Have video but no pics of the hail. Hopefully I'll get a better environment for working with the new camera)





Dann.

Beautiful Supercell over Denver (May 24th Chase Teaser)

While you're whining about the DEATH RIDGE ...

... I've been out chasing.

You're going to want to click for a larger view ... (you can see the Denver skyline bottom left)