Saturday, June 21, 2008

T-T-T-T-That's All Folks

I wish that some of you could have analyzed the data yesterday morning. We could not find a hint of a low. In fact pressures were in a high with values over 1015mb. No flow at either 850 or 700 mb with an actually weak anticyclone. But a jet at 250 across CO/KS hinted at thunderstorms that might be severe. Since we are here to chase there was no way we could pass it up.

Amazing things that the atmosphere can do. I think the reason storms worked better was that they were not strongly forced. There was not a lot of cell interaction and cold pool generation that we saw the last few days with the strong OFB's left behind. So these storms had the ability to develop a nice strong mid-level circulation.


We had no target so in all fairness much was luck. But some "better" moisture was left behind in SW KS. Storms seemed to be pretty big windbags in CO. As we were just north of Johnson City KS the tornado-warned storm (OH COME ON!!!!) came into view. Very high-based to say the least. And it too was outflow-dominant. But a storm formed a little to its southeast in some better dew points (upper 50's). Ths storm put out outflow that created a big dust plume that in essence killed its predecessor. This storm however started to get its act together. We headed to get south and east of it and were soon treated to a pretty good storm. The low-levels were pretty lame, but the mid-level exhibited a large circular structure displaced to the south of the rain core by some distance. Radar confirmed this quite well.

As we moved south we heard reports of 2.75" hail. This correlated with a very large BWER with the southern end of the mid-level reflectivity circle over our heads. The 250mb winds were more westerly than days before or I fear we might have found more large hail! We headed south and another storm formed to its southwest. The lack of gasoline and time precluded us staying with it any more.

Overall, a good chase. We are headed home now with no tornadoes but many supercells. And stories. And a slightly dented vehicle.

Friday, June 20, 2008

Deja Vu

We chased the monster AMA storm last night. A strong OFB from an ongoing (stupid) MCS across Kansas surged southwestward and kicked off a number of storms across the eastern PH of TX. The anvil of these storms were so soft I felt like sleeping on it. So from the get go we knew it was elevated. Originally, we had headed south west but the cu's were completely pancacus. It was soon after that the storm exhibited some good rotation and there was a notch in the OFB on radar. I had supposed that the storm *could* have become tied close to the OFB so we headed to see it. It was clear that the OFB would surge very far with some 20-25 degree temperature deficits.

It had a pretty scary shelf cloud and it had a great turquoise appearance. Given our track record this week with large hail and damaging winds, we decided to stay south of the storm.The outflow was more than ten miles from the storm itself. Even the shelf cloud was displaced north of the surface flow cold air by a few miles. We headed south and east to see another tor warned storm but as we got close, the stratus deck indicating elevated lift was many miles south of the storm. Couple that with the 35kt northeasterly wind at an observing site 10 miles from the storm, well you get the picture.

I continue to be amazed at the amount of tornado warnings. There was one report of a tornado with a third storm further southeast...so I could understand that tornado warning (although I do not believe the report.) Maybe a gustnado, but who knows for sure. Unless we have visual evidence. The other storms were so obviously undercut.

Now I know Markowski maintains that a storm could still be considered "surface-based" as long as there is still *some* SBCAPE. But I would have a hard time thinking that the air is buoyant enough for a tornado to form. We are not talking a few degrees of negative temperature perturbations.

Anyway, we headed toward Lubbock for a nice Cagle Steak dinner. Spectacular lightning for several hours and interesting cloud towers made for a nice weather night. No complaints there. Today, we go to Colorado because we are suckers for punishment. I love chasing in the middle of a synoptic high.You people who like to save money and only chase when there is a good set-up really ought to learn to chase when things are really lame. At least there is no chaser convergence. Although, I could use the company. :-)

Monday, June 16, 2008

Success and Failure


Wow. AN incredible day! And scary too. This is just a short summary. I will try to add photos later. Intercepted three supercells in OK and TX. The first was LPish and we left it as a tornado warned storm was just a few miles to its east. Still a nice look to it.

We got on the storm south of 40 near Lone Wolf OK. In the Washita Mountains, the storm looked scary. It was tough to get ahead of it but managed to on RT 283. Matt was saying there was a big visual vault. I couldn't see it until we turned south. The storm was one of my top ten supercells I have ever witnessed and clearly it had the most CG lightning I had seen. I have a number of daytime lightning photos. Continuous lightning and very stacatto and scary positive bolts.

We followed it past Snyder where it lost its strength and lined out a bit. It had some low-level attempts at circulation but never appeared to want to tornado.

Then to our southwest was the next monster supercell. We headed for Vernon TX where we tried to get south of it on 70. WE were slowed by near zero visibilities in the inflow dust. A very strong appearance visually. Our level three data didn't seem to show very much until we lost it. I am not sure why it looked so garbled. Either way, we headed south of town...we were about three minutes short of a south turn when the storm cored us. Large and very solid hail dented the van and knocked out one side window. Sizes were mostly golfballs but a few tennis balls. Kelley, my student, was cut and bled some with the glass that shattered into the van. Another student was subsequently hit with another hailstone in the open window. We ended up taking her to Quanah Hospital where she was treated and released with a few minor abrasions and a hematoma on the nose. We need to get the van window replaced. It was scary. SPC..storm log take note. Winds were also estimated to be over 60 mph.

Three minutes earlier and we would have made it. I feel bad for getting us there and wish we had been able to turn south quicker. The radar we had showed that we were very close to the south side of the echo core. But not far enough given the strong upper northerly winds. Must have been a beast of a storm.

see http://weather.cod.edu/~sirvatka/weatherweb/june_16_2008/

Paul

Texas Panhandle Again

Obvious situations given, there is a subtle shortwave riding over the ridge across the SW near the nrn border of AZ. Stout cap observed at AMA will be breached withwith hot and high LCL conditions like last several days. Better moisture shows up further east...will see if pooling occurs near weak sfc low over panhandles. I would think that the areas in CO will not be very good with winds taking time to become more easterly rather than northeast. The exception is near the mountain circulations along I-25....but no reason to think that will be great storms there.

We will target eastern OK panhandle/NE TX PH and find some localized convergence later. Not a lot of driving to do today so I am glad for that.with hot and high LCL conditions like last several days. Better moisture shows up further east...will see if pooling occurs near weak sfc low over panhandles. I would think that the areas in CO will not be very good with winds taking time to become more easterly rather than northeast. The exception is near the mountain circulations along I-25....but no reason to think that will be great storms there.

I still like being here!

Sunday, June 15, 2008

Stop the Driving Madness

What a frustrating day. I am getting tired of driving and driving. We left OKC at 10AM heading north to ICT. Obviously, we were concerned about the ongoing showers across KS/OK. As it turned out that ruined everything. Pretty hilarious PDS watch/mdt risk in KS. Not a whole lot went on there. And the models were no help. We thought maybe NW OK looked ok so we headed south again. Hung around near I-35 because a nice looking tor warned storm appeared in northern KS along the remnant OFB. Shoot...could this be the start of good storms? South of the warm front the dew points dropped ten degrees...further south, even less. As it turned out, the storm died a horrific death and nothing good really went on in KS. We headed west to see what cu's formed on another boundary.

In Camp Houston, we saw towers to the north near our possible original target. We watched for a while but decided to go after the tor-warned storm in the TX/PH. By time we got there, it died. Had a lot of lightning and very strong winds. But still nothing too good for 1900+ miles in the last three days.

Tomorrow, hopefully close to Guymon where we are now.

Stop the Madness!

Today is quite simple...lots of CAPE adequate shear and a big forcing front. Ongoing convection is setting up all sorts of boundaries. So here is our play...get really lucky somewhere in Kansas. All you have to do is be at the exact right spot at the right time and then maybe you will see something that you can fool everyone into calling it a tornado. Add 24 kts of rotation, get a tornado warning issued, call CNN who can report on the record number of tornadoes and you got yourself one heckuva a trip!

Gosh, really, we are heading to ICT and trying to figure out if the storms go away in Kansas...or they keep rumbling east. I really have no idea what to do with anything today. A crap shoot at best. Maybe the surface obs will hint at something later. Not a lot of confidence that the RUC will nail things. But, hey we can hope can't we.

Friday, June 13, 2008

Chase 4...gotta get better than this.

We were planning on chasing today. Until a watch went up at 11:30AM and turned into a
crappy line within two minutes. So we went to Kansas City and to Jess'n'Jim's.
Traffic in St Louis, an accident on I-57 and slow gas in the middle of Mo
is making this a very long day. We should be at the restaurant at 9pm. We
will chase in SW KS tomorrow...not in agreement with SPC with only the
panhandle. So I am thinking more like Dodge and points south as storms
move south into OK...looks like we might be there for a few days. Tough
week to find anything...but at least we won't be in Iowa.

Wednesday, June 4, 2008

Iowa Tornadoes

Dave Mayhew, Tyler Allison, John Volmer and I had an itching to chase. So we did. Tomorrow was going to be the big day but we might as well try to make the most out of today. We could make Nebraska in time for storms. I was not impressed with the forecast winds but there was a warm front that had been active and the storms that would fire near it today should travel along it. So we headed out after John had a meeting at the DuPage EOC.

I figured we could make Des Moines by 4 PM and Omaha by 5:30. But instead, a storm forming along the river of the IA/NE border grabbed my attention. We headed south on 59 and aimed at that storm. Within about 15 minutes of our arrival, the storm was tor'd with a spotter report just on the NE side of the river. We got it about 15 minutes later and watched a fairly disorganized storm. It had a well defined clear slot but we were unable to figure which updraft might produce the tornado. There were a few regions of ascent apparent. We stayed with the storm as it moved east when I saw a brief spin up beneath cloud base. Tornado one near Malverne.
We stayed with it a little while and as the hook on GRLevel3 got better, so did the storm. Tyler saw it first and it was on the ground about 5 minutes.


After it lifted, we kept with the storm and again saw it cycle up a bit. We watched it near the town of Emerson.
We followed the storm further east but although the inflow increased, the storm looked outflow dominant. Radar showed large scale rotation which is what it looked like to us. We left it.


A few minutes afterward we heard a report of a tornado right where we had left. I am doubtful of that report although the wind in the RFD could have been strong. Oh well...lots of rain and things that were tough to spot. We saw a few good ones tonight and more might be on the way tomorrow.

Paul