Thursday, April 30, 2009

Can't it just go easier?

What a weird day. Targeted areas along the Red River near Vernon, TX. Had a great lunch at Rock Inn in Seymour. Awesome place! Gotta have some homemade pie!

Anyway, after watching the outflow boundary (OFB) head a little north we decided to cross into OK. Watching cu's bubble along the dry line and further NW in OK we thought we would hedge our bets and play in the middle. We sat for about 2 hours in Granite OK. We waited and waited until after 7PM. Nothing was going on so we called the trip and were going back to the hotel in Lawton. Twenty minutes later we turned the corner and as I looked to the NW a series of strong towers had broken the cap. Just then Sam from the weather lab called me and said it was showing up on radar.

Of course! Couldn't have started twenty minutes earlier.

So we cruised north. It took a while but we made it just in time to watch a tornado warned storm about two miles to our north. We saw an attempt at a low-level occlusion with a rainy core wrapping into the updraft. No tornado was visible and we had a very good view of it. We watched a while longer before heading west to reposition to the storms south. We watched an incredible lightning display until the storm died soon afterward.

It would have been nice to have been there a little earlier. But at least we got there. That is 8 supercells and three tornadoes in 7 days.

And tomorrow and Saturday look good!

See David Mayhews site for an amazing wealth of great pics from tonights storms.
http://www.davidmayhewphotography.com/

A few more details

Pretty frustrating day as I mentioned on the nowcast part of the boards. Left Odessa after lunch to see storms to the north and a red box issued for them. We cruised north realizing the dry line had mixed further east than I though. I should have known that it was going to be loosely defined since it was not dynamic with a well-defined pressure trough. As we finally got back into the better moisture near Big Spring it became apparent that nothing was going to happen with that wave. What is it with all the high frequency short waves this year?

We saw the storm that was about 50 miles south of Odessa go tornado-warned but decided we were going to stay within our forecast area and not chase it.
We did think that the newly formed outflow boundary would be a great mechanism for new storm growth and tornadic potential with enhanced vorticity. But of course, no storm formed in that region at all. So after making it to Gail, TX, it became clear to us that the only real good storms we north of that boundary along some of the older (and colder) ones further to the north. Wind fields were weaker but you have to have storms before you can have supercells.

So we flew north (gosh I had forgotten how beautiful that part of TX is!) The storm that came off from Plainview (which btw was in an area of cu's that had been present north of the dry line bulge) was moving more easterly. Further to the west that was a real good supercell with tor's out and several other cells forming on some old boundary. They had a more northward moving motion to them and I felt that the storm out west could move just south of those others and move right along a better moisture or outflow feed.

As we were near Floydada, we could see excellent tower growth to the NW so we pressed northward. As we approached there was a high based shelf cloud that looked almost base-like. Given the conditions, I felt that could not be the true base. Matt Powers texted me that on radar it looked like a big cold machine and I agreed. Nonetheless, I felt we needed to get a better look. Inside that base (and wide RFD) I saw a lowering, not unlike other HP storms with the low scuddy wall cloud. Given its proximity to earlier convection I wanted to make sure that it was really cold inside there. Heading north our driver radioed that it was a tornado he was observing possibly. I warned him to be careful of those words over radio and we were still too far to be sure.

We moved north and it was a large barrel-like cone as Scott Blair indicated. We were driving right to it. We got out and snapped some pics.

A second tornado formed to its east at the same time. Enhanced shear along the gust front I reckon. We got onto some really hairy mud ruds so we headed back south and west. A student believes that there was a third tornado and I tend to believe him. (so that might make Scott B's third if he did not see the secondary needle.)

After heading south I saw vigorous cloud growth and figured I would bust south near Dicken's to get to these storms in less tainted air. There were impressive towers. Just east of Dickens we saw a great looking and scary storm. Todd Lindley from LBB called me and said they were interested in that storm as an OFB from the north storms was surging south and about to interact. We watched for a while and there was very strong low-level rotation. Unfortunately just as I though it had a chance to tornado, temperatures dropped like a rock and I knew it did not have a chance.

We were not going to play in the core so we bolted west and south to get out of its beasty path. Lots of loops and CC bolts made it fun to watch for a while. All in all, a saved day.

Wednesday, April 29, 2009

Cedar Hill Tornado!




After a long, very frustrating, but greatly rewarding day, we saw a tornado. It is very late and I am tired, but the basics are:

1 - We saw two tornadoes (maybe three) north of Floydada near Cedar Hill.


2 - We caught another storm that was close to producing a tornado until it laid down very cold outflow.

Some success finally!

A very frustrating day was saved by an hour's worth of excellent storm viewing. Our target area convected twice only to sucker us away from storms further to the north. The lack of low-level lapse rates probably killed us. More about that later when and if I have time. It was frustrating because we kept going around in circles. We finally got back to Pecos when the storm on extreme southern NM started getting its act together. WE decided we could catch it if it turned right (which it did!) and we were treated to a great view of a pretty storm. Never felt a tornado was imminent although there was some good motion beneath the wall cloud.

I took a few picture which I will try to post later. My card reader may not be working so it may have to wait.

Today:

Two outflow boundaries are present: one near and just north of LBB and the other about two counties south of there. Dry line will take a while to really get going and will probably not make it too far east due to the presence of intense and deep moisture. Great EML will cap things a bit but allow for explosive development later today. Morning analysis and RUC mesoanalysis indicate excellent mid-level flow will probably be further south than the areas of the northern TX PH.

I believe that the nose of an analyzed and forecasted 259 jet will makes its way into the south plains, tighten the dry line and bulge it slightly. The proximity of the OFB's and the dry line should be there target point. Early target will be in the Lamesa/Seminole region. Would not count out just north of LBB.

As others have pointed out, 700mb is weak and I do not have much hope for improvement. Although it may be sufficient for wet-classic type structure early. Monster hail may be a problem with a well pronounced dry prod west of the area. WRLY UT jet flow may also throw that hail and precip to the east so be careful from where you observe these storms.

BTW...tomorrow may have more impact in TX that originally thought....if the WRF is to be believed.

Monday, April 27, 2009

Dang! I wish I were going to Mexico!

Confusing models from earlier but looks as though upslop will be difficult to get rid of tomorrow across the southern panhandle. The WRF shows nothing good but not sure about the ensemble members. I suppose they could break or be completely overdone.

Nonetheless, it is late so here are the pros: Great shear for supercells. Large low-level SRH. Mean flow that is slow. Potentially a lot of instability. Dews across the coast are in the low 70's. DRT looks like moisture is about to make its way up the valley.

In short, Saragosa and areas tucked in to the Davis Mountains could be under a threat tomorrow. Serranias del Burro will probably go big tomorrow and other times this week. I am hoping for a storm on the US side (no border crossings for us this year!) and if you look at the progged sounding for DRT, it is impressive.

So, we leave LBB early tomorrow and see if we can determine west to the Davis Mountains or South to the Rio Grande.

Paul

BTW...we will NOT go to Mexico. Not this year. Too dangerous. Someday if the US stops using drugs and we kill all the drug lords.

What a bust

Yesterday was lousy. So many things went wrong. Very little went right. Big steep lapse rates but no cap. Lot of shear if the storms turned right which they didn't. A thousand storms to choose from, only a few rotated. Only one produced a few tornadoes. Overall, not good. We saw one storm that was alright. Near the Red River southwest of Altus, OK. Had a cool wall cloud and for a few minutes looked like it wanted to tornado. But it did not.

I think the storms moving to the north east (probably from 210-220) and surface winds from the southeast (at most from 135) just didn't give a lot of chance to for low-level shear to really catch hold. No long-lived supercells. For what was expected, we should not have had to try to find the little bits of rotation in these storms. The one that produced tornadoes was nice for a little while. A lot of storms had gone through about the same region and did nothing. The one did.

We will never see everyone. We will miss storms. But that was too difficult yesterday. You were either there or someplace with a whole lot less promise.

I did say northern Iowa looked good. And sure enough, they had a tornado. Figures.

People liked the storms. So I was happy for them. I can't wait to show them storms that make me excited. Maybe tomorrow.

Today was a down day (mostly.) Stupid MCS ripped through Texas and took all the good juice with it. Tomorrow has promise. We are going to Cagle's for some good rib-eye tonight. Yeah! And Shiner. Yeah again. Not all is bad in Texas!

Paul

BTW...Old Faithful in Mexico had a cool looking supercell again today! Too bad there are so many shootings. And Swine flu. One day, it will be safe to chase there and I am going to again!

Sunday, April 26, 2009

Day 3...early start

Got a call this morning from Sean at 8:10 (Grrrrr) but he informed that an MCD had been issued for our area. Oh well...got up and saw that we still had some time. We are all ready. Lots of stuff going on today. Big shortwave coming in from NM and it should influence stuff soon. But here is the key.

Some outflow boundary is sitting in place southeast of AMA. Storms should fire along dry line is it moves east. If a storm can interest that boundary, good things could happen. So we are going to target between Clarendon and Silverton TX.