GOOD RIDDANCE NAM/ETA!!!!

After much gnashing of teeth and pulling hair this chase season, the horrible and pitiful ETA "engine" driving the NAM output is retired. Good riddance. When you can't even halfway rely on a model even 12 hours out, it's a serious problem. I can't even begin to count all of the setups that it totally missed this year. It wasn't just moisture problems but upper air and surface features as well. I quickly got to the point that by late April and early May, the NAM model was last on my forecasting list with the RUC (for Day 1 setups) and GFS ahead of it. Yep....I'm glad to see it go away.

In it's place, and as I noticed today on the famous UCAR models, the NAM is running with the WRF (Warf...as in the Klingon) "engine". In a nutshell, it is sure to be a major improvement. Alot of the test phase results I've read about are certainly promising. For a nice technical multimedia presentation targeted for operational forecasters, click here and click on "Begin" on the right. Some of it might be a tad too technical for some, but there is alot of "meat" to it. I strongly recommend it. In the future, I'll post other sources as I can find them. I consider this to be an extremely important subject for stormchasing since model performance is directly related to the costs incurred...not to mention the time involved along with commitment schedules. The old NAM/ETA output has cost chasers ALOT of money and sanity this season. And, of course, it certainly adversely affects those more concerned with the competitive/commercial side of stormchasing. :-)

Here is my plain english interpretation/highlights of the important changes and differences (I appreciate any corrections and additions in the blog "comments" section).

1) MUCH better analysis/initialization...similar to GFS. Alot more use of satellite derived data will be ingested. This allows a smaller grid initialization as well as covering gaping holes. I'm not sure about the all of the types of satellite data being used, but what I'm aware of is that temperatures and moisture will be part of that. I'm not clear if that includes all levels of the atmosphere or just the surface. I have to think that it is the entire atmosphere such as GOES soundings. I'm also not clear if satellite derived winds will be used or not. NEXRAD L2 winds (I assume the VAD profiler data) will be used as well. Speaking of moisture, soil moisture will now be used and the gross evapotranspiration bias of the ETA engine (which caused most of the problems for us this year) is now corrected. In general, the WRF engine will entail better moisture analysis and forecast of GOM return flow (YEAH!!!!). The other thing I like is that the WRF will use 3 hour analysis corrections of the "first guess" forecast output. This should result in much better resolution and handling of surface features closer to the mesoscale level. The mesoscale parameters should be more sharp and accurate. (YEAH!!!!). There will certainly be alot of performing the "Forbidden Sacred Dance of Chaser Merriment" by yours truly.

2) For the "upslope" and mountain terrain fans, the WRF is much bettter in this area. Better handling of moisture and mountain wave/flow dynamics will surely be noticed. Higher terrain forecast should be improved including windflow. They refer to this as "improved terrain flowing coordinates". I would think this would directly impact leeside troughing and cyclogenesis. I'll be keeping a close eye on this aspect.

3) Since the WRF will be implementing the NMM (Non-hydrostatic Mesoscale Model), certain algorithms come into play that handle vertical velocities and forcing MUCH better and in much finer detail/resolution. This will result in better forecasts of UVV parameters. This should directly correlate to improved convective initiation and helping predict if the cap can be busted....and the amount of linear forcing. Something else I'll be paying attention to as well.

4) Better handling of sea surface temperatures. This would seem to have a slight impact on the GOM return flow and moisture quality, but mostly for tropical systems I would think. Speaking of which, the WRF has demonstrated a signifcant improvment in handling tropical systems.

5) For model output sources that implement it, simulated NEXRAD reflectivities will be available.

Some biasis are noted though. One of which is that the WRF might show a slight dry bias with time as the forecast progresses. This is in part to the revised evapotranspiration algorithm. Also of note is that the WRF deepens troughs too much. I want to find out more information about this myself as this is a critical parameter. How much is "too much" for instance. When does it occur? Lost of questions there. Some of the convective triggering mechanisms are the same as the ETA. This might not be a bad thing if the model now has better moisture and UVV forecasts to work with. The WRF will still likely struggle with the shallow arctic airmasses in winter as the ETA did.

So, in summary, my take is that it will be a vast improvement over the ETA driven NAM. It will resemble the RUC to a degree. Of course, a Ouiji board, magic 8-ball and a crystal ball would be an improvement over the ETA engine. :-) We should have alot of time over the next 9 months to get familiar with it. Hopefully it will reduce ALOT of frustration next year for everybody.

6/17 Report and Pics

Another day of cratering dewpoints and screwed up parameters. I was completely stunned in how much the dewpoints dropped across the Red River Valley and our source region in North Texas. There also seemed to be some sort of upper level dynamics in play working against us as well. Storms seemed to sputter of southern OK as they reached the I-35 corridor. I'll venture to guess that perhaps a left entrance jet region existed here creating subsidence. Either that or the impulse that fired up the SW OK storms early created some subsidence in it's wake. Or maybe it's just the '06 evil curse. LOL!!

I started off the day in Lawton crunching data. It was an "unorthadox" setup with everything from the surface to 250mb.The models struggled with various solutions with the 15Z RUC having the best handle on it in retrospect (although it had it's quirkiness too). Everything said that Lawton vicinity and S Central OK had good potential for a chase and perhaps a brief tornado along the OFB. I also liked far N OK and S KS, as I posted yesterday, because of proximity to upper low. They got two naders up there before the end of the day.

After meeting up with J.R. Henley for lunch at the Cracker Barrel, we put our two brains together to compute a solution. When we finished and got to the parking lot, towers were erupting all around us to the south, west and north. Surface analysis showed a small but pronounced dryline punch coming into our area...southwest gusty winds with dewpoints in the upper 50's punching into S and SE surface winds with dewpoint in the upper 60's and even 70. Confidence was high at this point with the W-E instability axis along and north of the Red River. The winds were already shifting to the SW there in Lawton and we could see towers rapidly building to our east along the convergence, so we headed east to get out ahead of it.

Cells started going severe and the leading storm along the "dryline" started showing some weak rotation on GR3 and a nice developing wall cloud that visually presented some evidence of cyclonic rotation starting up. Everything seemed to be going our way until about an hour later when the storm got linear and high based then split with the right splitter fizzling. I looked around to see if Rod Sterling (the old Twilight Zone host for you young 'uns out there) was going to step out from behind a tree and reveal that this was some sort of sick, twisted and demented psychological nightmare. :-) I saw Shane, Mickey and Chad on the side of the road, so I and J.R. stopped and jokingly accused them of messing with my storm. ;-) We unanimously cursed the storm and '06 in general and proceeded eastward. I think they all headed to the northern storms still going on and I made a vector southward towards home hoping to catch a few good cells along the way. I was tired of high based linear crap with dewpoint spreads of 30F or more.

A strong storm got going just west of Ringling and started looking pretty good. Some stronger easterly winds were feeding into it and I thought this might be the magic missing ingredient since surface winds literally died ahead of the earlier storms. I glanced up along the leading edge and saw a nice shear funnel snaking out of the edge of the shelf cloud. Before I could get the camera, it started dissipating, but managed to catch a couple of shots. It started peaking just around Lone Grove, but it too quickly fizzled as it got to I-35.

I noticed some good storms erupting across NW TX and a couple of cells firing up in Palo Pinto county, TX. I remembered the models progging a nice jet on the backside of the trough diving down into that area with a pronounced left exit region, so I figured I could get some good lightning opportunities and who knows what else. As I got about 20 miles south of the Red River, I saw the tornado warning go up for a spotter confirmed tornado near Mineral Wells. Dammit. (I remembered seeing a nice OFB laying out there from satellite analysis earlier...and this storm latched on it).

I ended the evening with some pretty good lighting shots over Denton County. I retired back at home with a couple of Shiner Bocks.

Getting ready for some rotation. This as good as it ever looked.



I end up drawing an audience with a gang of overly-curious punk bovine (dig those cool green ear tags).


I farted and they ran for their lives. LOL!! Actually, I was downwind of them at first. As soon as the winds shifted and they caught my scent, they bolted.


Nice structure around Ringling....but wait...what's that protrusion?


Yeah...a shear funnel. Sad that in a year like 2006, this generates storm wood. I was happy to see it.


The storm as it approached Ardmore.



And now...some lightning shots:



Note the persepctive here. The bolt starts out quite a ways west and "shoots" right towards me and curving off to my right off frame...and close too.

6/16 Pics/Report and Today's Thoughts

Storms were pretty stout, but didn't look all that great visually....just some high based severe storms as I expected with dewpoints mixing out into the upper 50's. However, as they moved into OK, they really cranked up as they found some moisture. Unfortunately, the storms overtook me as I missed my turn near Sayre and then got stuck in a construction zone where I-40 narrows to one lane....suddenly. An 18-wheeler tried to climb into the backseat with me. This really screwed me up and I spent the rest of the evening with the jaws of the SW OK beast nipping my ass for awhile as it moved at 40mph. I found myself in the notch a couple of times with blinding rain and intense winds. A couple of times, the winds would shift direction 180 degrees and intensify as if a tornado was trying to form on top of me. Scary stuff.

I finally got our ahead of this thing NW of Lawton and got some night pics. The structure was ALOT more impressive earlier but I didn't have time to stop and shoot. I wish I had now...it was pretty awesome. I also passed up an incredible lightning opportunity earlier when the cell first went TOR. There were numerous combinations of intense anvil crawlers punctuated with a CG. Hindsight says I should have seized that opportunity as it would have been among some of the best I've shot.

I was happy to see my target of Tulia/Memphis verified early on....too bad it wasn't more impressive visually. Here waking up in Lawton and based on analysis this morning, think I'm at a good spot for today's potential.

The 850mb winds are progged to veer more today and the vertical wind shear is progged to be weaker from 0-6km. However, 70F dewpoints across S OK and N TX combined with the lingering cloud cover and overnight convection to keep temps down will favor lower LCLs to take better advantage of the 0-3km veering profiles. A nice outflow boundary extends from near Lawton to Ada and has already sparked on strong storm east of Duncan. As we get insolation today, CAPE values should reach 4000 easily down in my target area. With that kind of instability, the vertical wind profiles are certainly adequate....especially if the OFB hangs around today.

I would also seriously consider far N OK into S Central KS in the vicinity of the upper low. 0-3km profiles look pitiful...but that is the model forecast as of 12Z. Things could change. At the very least, some impressive and photogenic cells should erupt up there.

As for now, I'm hanging around Lawton until I see a specific target coming into focus..which very well could be the parking lot of th Super 8 here. :-)

Pics from yesterday:

Forecast - 6/16 - TX PH / W TX

12z NAM/RUC in very good agreement with surface and upper level features combining to create excellent dynamics for some powerful storms. I think RUC has better handle of dewpoints being mixed out abit more than the NAM depiction. Visible satellite and upper air analysis still show moisture to be shallow with the exception of Brownsville fianlly showing some decent moisture at 850mb. So, it makes sense that dewpoints will mix to below 60F across W TX and the PH with perhaps localized moisture convergence along the dryline to maintain a few 60Td readings. With temps soaring into the 90's, LCLs will be high (a common theme for 2006) and with colder temperatures aloft, cold pool generation will be extremely strong and rapid.

However, storms should be pretty severe and produce some stunning structure... perhaps even a good haboob setup. There is a possibility that towards dark as storms move further east and mixing relaxes, that some better moisture will make it into the storm environment and with a LLJ, they should continue to be severe through the night. Any discreet storms or tail-end charlies could have a little better tornado threat when that happens...but I really think it will all be strongly linear by that time. Overall, I wouldn't outlook greater than 2%.

My target? Near the forecast dryline bulge/punch from Tulia to Memphis and 25 miles north and south of that line.

I still belive Saturday has better potential for tornadoes across TX anywhere from Wichita Falls to San Angelo. Details on that in the morning as ALOT will happen between now and then creating numerous variables (such as boundaries and insolation potential) impossible to resolve at this point. The potential is certainly there though...stay tuned.

Happy Happy, Joy Joy

Just as everybody starts putting their chase gear into mothballs and writing off the rest of the season, we are facing a couple of good chasing opportunities for Friday and Saturday. The models are looking better and trending more positive with each 12 hour run. With the SPC now outlooking Friday as a slight risk, it's catching everybody's attention and rolling out the bandwagon. ;-) I admit I was pretty pessimistic previously, but the model consistency and agreement is remarkable this far out. The moisture return gets better with each run and should be ample to crank out some pretty severe storms on Friday when combined with such strong dynamics aloft coming into play. Any outflow boundary interactions will prove to be critical for any tornado opportunity.

Based strictly on model analysis, I'm liking the general area from Lubbock to Paducah for tomorrow. Best veering and shear profiles will exist here as well as what I think will be deeper/better moisture profiles (despite model progs at this point) as well as remaining a little more discreet/isolated in nature....although likely firing up later than stuff further north into the PH. Any pronounced outflow boundaries from possible early morning convection will have to be considered...if they do materialize and are strong enough to resist mixing out.

Saturday will have MUCH better moisture to work with and resultant instabilities. The models keep trying to target the Abilene/Brownwood vicinities and for now this seems like a good bet. I think there is a good possibility of some outflow boundaries to deal with from heavy convection up in OK and the Red River valley region. Again, vertical wind profiles look to be awesome (as advertised) in this target area.

Those are my thoughts at this point. Alot of variables still to be played out. The one thing certain to come out of this is a signficant rainfall event for the northern half of TX and OK where a new desert region is evolving....the Texoma Desert. Everybody here will be rejoicing heartily for this alone.

I will be out chasing this event as it could very well be the last hurrah for us southern plains nomads. Stay tuned!!!

The Siren Call of The NAM

Damn. If that 00Z run this evening doesn't look alot sweeter. Somebody help me. I'm being lured in by the siren call of the models. I fear I may crash my vessel into the jagged rocks. ;-) It's only out to 12z Saturday, but you gotta love the extrapolated 6-12 hours afterwards...especially if it slows down a tad. Friday has potential, but moisture (and resultant instability) won't be as good as Saturday...when the -10C 500mb line crosses well into TX. We'll also have a good, deep boundary layer flow off of the GOM boosting our dewpoints significantly higher than that of the Mojave Desert. Lots of convection in OK could lay down a nice outflow boundary too. Still a ways out though to keep being silly about such details at this point. Alot could still go wrong....and probably will. We're cursed. ;-)

Chase Season Sputters Along

Some upper air pattern changes are on the way. It's hard to have any optimism in a season (since early May) that has continually trended negative with each potential setup advertised by the models. The biggest caveat has been adequate boundary layer moisture. The latest models, including the NAM, are showing a strong fetch off of the GOM from the surface to 850mb (~5,000 feet) starting up early Friday. It will be interesting to see the results. However, I'm a pessimist conditioned by the middle and latter parts of the 2006 chase season.

Upstairs, an approaching trough is advertised to merge with an upper level weakness/low over the GOM waters just off of the Texas coast. The result will be a broad, although weak, trough over the Colorado Rockies into New Mexico and the Texas Panhandle. It is certainly appearing possible that somewhere in the southern plains will see decent mid level flow from a general westerly direction. At the same time, the boundary layer winds pick with broad, relatively strong southerly flow all over the southern and central plains. A pronounced cool front will sag into the central plains and down towards the panhandle region with a surface low progged to develop in that area.

In short, a period of convective activity across the southern and central plains will begin in earnest starting Friday and possibly through Sunday as the upper ridge is smacked by a trough. Details are of course impossible this far out. But, at least it appears we have a system to watch with at least a remote possibility for some severe storms to chase....perhaps the last chase possibility of the season here in the southern plains and Kansas.

The good news is that the rain prospects for this drought-ravaged region are looking better. If the longer range model trends are any indication, Texas at least may come under the influence of broad easterlies setting us up for a more tropical-like pattern with daily diurnal convective chances and temperatures on this side of the boiling point of water.

Forecast, Drought, Musings

First, congratulations to our American Armed Forces for terminating al-Zarqawi today. Well done. May the bastard burn in hell. I hope ya'll come home soon.


Now for some chasing stuff.....

Just as everybody starts writing off 2006, some faint glimmers of hope (or mirages) are being served up by the models both this weekend and beyond. Since their performance even 24 hours out this year has been about as reliable as rolling out a full house on the "river" in Texas Hold 'Em, I'm not ready to call Ma Nature's bet just yet. She's been a tough and ornery opponent this year ;-) I'm liking the "flop" though with this evening's NAM for Saturday's setup. If we can realize dewpoints in the mid to upper 60's, after adjusting for the typical NAM bias of mid to upper 70's, then CAPE of 3000j/kG should be realized. Intense surface heating with forecast temps to the south of the front nearing 100 (with temps in the mid to upper 80's north of it) will aid in intense low level lapse rates and energy. With a stationary front/boundary in the area and 30 knots westerly mid level flow atop of easterly low level boundary flow to the north of the front, the stage would be ideal for a tornadic supercell if it can ride right along the or just a hair north of the front. However, we got two more cards left to play. I'm preparing to go all-in early Saturday morning to make the drive to southern or central Kansas...wherever things setup. I might fold too. :-)

The drought is back and more fierce. Many municipalities across Texas are now in a Stage 3 drought contigency and some up to stage 4. My city is in Stage 3. No car washing. You can only water your lawn in the evening or early morning ONLY on your trash pickup day once per week. Hand watering by hose is allowed as are soaker hoses. They have added an additional surcharge to "motivate" me to use less water. Violations are subject to up to $2,000 and repeated violators can have their water cutoff. All city personnel including police will be enforcing and reporting violations. There's even a hotline for the public to report violators. On the local news this evening, officials are cracking down everywhere and even cutting off water sprinkler systems. Stage 4 is alot more severe and I'm afraid we are heading there later this year. We've got it good here compared to the Texas Panhandle where Lake Meridith, a major water supply soure up there, is down to 10-15% of capacity. It could literally dry up to a mudhole later this year. I'm not sure what they will do if it does. I'm trying to find out.

In more amusing topics, it's that time again, kids, for the light bar debates....and awfully early:


As the one who discovered and first identified SDS and continues studying this disease, I'm quite alarmed about the premature off-season followed by such a horrible and disappointing 2006. I predict a spike in the severity of SDS never before recorded in modern chase history. It is going to get real nasty. You see here a couple of GrailChasers approaching a roadblock. We know the outcome of that encounter. :-)



(added 6/9) For the record, I think they are important safety tools to be used *responsibly*. Chasers operate within a hazardous and low-visibility environment. Alerting other drivers or chasers of your presence is a good idea, no? I've read excellent arguments for their use, alot by David Drummond, and the only opposing arguments concern a paranoid perception that "somebody" out there "might" perceive it negatively. What I find rather amusing is all of the strong and emotional rhetoric about chasing safety...only to see alot of people get bent out of shape over the use of safety equipment. LOL!! I'm getting one for my vehicle now. :-)

Yes, it is going to be a long off-season. I'm going to stock up on the popcorn and Diet Dr. Pepper. :-)

Chasecation Finale

My shortened chasecation excursion for 2006 is over with. I made the long drive home yesterday from Goodland, KS believing that the rest of this week would produce only marginal events similar to most of my past week on the plains (less the incredible May 31 haboob I experienced). On day one of returning to work, I see the new SPC Day1 and can't help but laugh at the sadistic side of mother nature combined with the piss-poor model performances...even 24 hours out. Tomorrow and even a couple of days this week look great for upslope storms in CO.

I regret not sticking it out and deviating from my more optimistic nature. However, after four days in a row of marginally strong storms (even with the brief needle funnel on 6/3)....driving what seemed like a thousand miles each day....seeing dewpoints crater every day as afternoon mixing ensued.....and very poor model performance 24 hours out....it can wear you down into quite the pessimist. I was tired and just couldn't justify staying out any longer burning precious days off from work along with burning money for gas and rooms. I also have an obligation to my very gracious and excellent employer that allows me the means and flexibility to pursue my favorite hobby. Since I just started a few short months ago, I was really stretching my responsibilities.

So, it seemed the prudent choice to come on back early and sneak out later this month for a weekend chase if things improve. I don't think the season is over with yet and today's setup is proof of that. If not, then I'm looking forward to next year. I've had a very good season considering 2006 among the most dismal chase seasons ever. I'll let those more concerned with tornado counts and stats/medals/awards/stripes figure out my proper ranking. ;-) However, I think it should be somewhere between "Centurion" and "Praefectus Castrorum" (click here if you don't get it) or for the D&D fans...."ChaseWizard Level 7". ROFL!

The highlight chase was of course the 5/31 E CO haboob with a tornado that appeared to be on the leading edge of "forward flank" of the storm. However, radar showed a hook (which was visually apparent...look at my pics) and strong shear marker and I was told later a small but pronounced couplet on GR3 indicative of a forward flank mesocyclone and resultant tornado. I hope to find some good radar images of this event and put everything together into a more cohesive case study. I got some great video of at least one of these tornadoes. It was a fascinating event and my first "forward flank tornadoes" (or hybrids....whatever your preferred terminology...they're still tornadoes).

The other good chase was 5/30 W OK with a slowly southward propogating supercell along the TX/OK border. This storm tried to go tornadic several times, but the outflow was just a tad too overpowering. It was a great storm though with a good CG show towards the end. I tried photographing the lightning with a couple of hours of daylight left. I tried a neutral density filter and cranked the f stop up to 22 with ISO of 100 which seemed to work. I should have used the manual shutter more though. I learned a couple things for the next pre-dusk event.

Lastly, the little surprise event south of Goodland on 6/3. These high based storms erupted near the surface low and along the dryline immediately to the south. I got a nice little needle funnel out of it and saw what might have been a brief attempt at a landspout. However, this storm didn't hold together for long and the "climax" was extremely short.

I also got in plenty of sightseeing (more than I wanted to actually...LOL!) and discovered the mountain areas west of Trinidad, Colorado. This is very high on my list for an extended camping excursion sometime in the future. It's hard not to think about that now here in the hot, muggy and hazy north Texas skies I sit in now. ;-)

For the details of each day of my chase excursion, click here.

Okay....back to work.