4/9/04: FCST: N TX & S OK


I have to work until 8:30am. So I will be making my decision on a target tomorrow morning. Needless to say I am going. I really don't think the moisture is going to be as bad as some are making it out to be. Last time I checked 60 to 65 dw were not all that bad. Any way tomorrow’s analysis will paint the picture for this chase.

Have fun and be safe...


George Tincher

The 1730 Day 2 still retains the 25% significant severe probability, so the SPC forecasters must feel there's a good chance of supercells and tornadoes, regardless of what the models are spitting out. Considering how often the models have been low on both CAPE and moisture leading into events this year, I am not placing a great deal of personal faith in them attm. I guess from this point forward it's a game of wait and see. Funny, isn't that always the case? Hehe.


Shane Adams

Well, my optimism hasn't fluctuated any after an intense analysis just now (intense for me is about 20 or so minutes, 10 on cable). I'm interested in both the ETA and GFs' stinginess with the moisture at 700mb....the ETA is somewhat lacking but the GFS is just plain arid. But then I realized that models are much like people, flighty and unpredictable.

The main consistency I see with both models is the nice concentration of CAPE at all levels in SW/SC OK/extreme N TX. I think this could be a major "finger" pointing the way to tornadic bliss tomorrow. Nothing I saw just now makes me feel confident in any one area 100%, but for now I'm liking my original target town of Ardmore. Of course, playing west of there will most-likely be the first plan of action tomorrow, but I expect to be in the middle of it by tomorrow evening somewhere along I-35.

I'm quite content to forget what I just saw and wait for the 0Z runs. Returned from work not long ago, so I think a shower and some Sam Adams are in order. I'll be back later after the 0Z runs.

I know that synoptically there's probably no big similarities, but I keep getting the feeling that tomorrow will play out much like the 27th, as far as initiation time/mode/evolution. The one difference I see is the large tornadoes will happen later into the event, not at the beginning.
Mar 2, 2004
Wichita, KS
Originally posted by Chris Rozoff
But who knows, I'm almost as insane as a *real* stormchaser.
And I am insane like a *real* storm chaser :D .. but I guess I'm not stupid, though... bad luck has forced me to withdrawl my name from the hat :banghead: .. on my way home to pick up a check, my car's front end began to wig out on me.. guess I knew it was due, especially after successfully surviving the 2300 miles I put on that bad axel going to Iowa, then down to Oklahoma and back :shock: . Fortunately it happened on Hwy. 6 five miles from my house and not in Sherman, TX 650 miles from my house..

In any case, with less than 4 hours before my departure time, I am going to have to take a sideline seat for this one (as it snows on me here)..

Best of luck to everyone, I will wear the lucky #81 jersey for everyone heading down! It's still early in the season, so I won't spit too much fire for this one :angryfire: .. glad I'll have some synoptic time to try and get this fixed and ready for when the real action starts!

Watchin' for ya!

Tony :cry:


I think tomorrow will be real borderline, but I will be out. I am thinking somewhere south of Chickasha and Pauls Valley in between 44- and -35, as tomorrow pans out I will decide 35 or 44.
Re: Some Thoughts on the 18 Z eta

Originally posted by Chris Rozoff
Early in the year, a year that potentially looks miserable for chasing from a persistence forecasting standpoint. (i.e., Jupiter's redspot situated over the western united states)
Can you please explain this comment - for a relatively novice storm analysis guy - how did you arrive at this view?



Kevin Scharfenberg

The convective system in the panhandle down into southeast NM is resulting in a large cold pool at the surface. The 00Z temperature at AMA was 48, as opposed to the progged temp of 65 by the 00Z eta. To me, this does not bode well for tomorrow's chances.

More after I have time to digest the 00Z data.

Jason A.C. Brock

Hey John

Is that the # for one of the local stations in SPS? If so which one and should I ask for anyone if I see anything interesting? You interested in Tornado reports only?


Kevin Scharfenberg

Short version:
Tonight's convection looks disruptive to chase potential in Oklahoma and much of north Texas. Best threat shifting down into the area SW of the D/FW metroplex. Supercells possible, but low tornado threat.

Long version:
The 00Z eta and RUC models have no concept of the cold bubble of air accelerating southeast across west Texas. For example, the 00Z eta says the surface temp in Lubbock at 1am will be 62. I'll bet the house on "colder".

The vort max responsible for this convection will lift ENE into Oklahoma in the morning as it shears out. This will carry the convection east, as the dense cold air in west Texas continues to spread southeast. By morning, I expect a large area of stable air roughly northwest of an San Angelo - Ardmore line.

The weakening shortwave trough and continued strong zonal flow over the terrain in New Mexico will keep the surface low virtually anchored over far NE New Mexico. The sub-tropical air will ascend isentropically over the remnant cold dome. The weakening, shearing and lifting nature of the lead vort max makes me suspect the isentropic ascent will win out over any subsidence behind the shortwave trough, keeping Oklahoma grunged in most of the day.

Farther SW, down toward Abilene, the cold pool will have a better chance to be eroded during the day, as isentropic ascent will be much weaker. If we can keep a cold ridge from anchoring down into deep southwest Texas tonight, the 00Z El Paso sounding suggests the dryline may be able to sharpen up. So I'd look for a triple point to set up somewhere down in the Abilene-San Angelo area.

Storm motion estimates, given a reasonable 00Z eta forecast profile, would take storms toward the east southeast, keeping them out of the cold/stable air. Seasonably marginal instability, combined with shear profiles that are "okay but not that great", make me think widespread/significant tornadoes are not a major threat.

Initial target: Rising Star, Texas.

Bill Hark

Jan 13, 2004
Richmond Virginia
Friday potential

Friday looks interesting but not exciting. On the 00Z eta, there is a nice projection of CAPE up to 1500 through central Texas that extends northward and shifts eastward by 0000Z into south central Oklahoma. SRH is better in central Oklahoma but there is still an area of 200 m2s2 that extends to the south into Texas. The low shifts into the Texas Panhandle with backed surface winds across the Red River Valley by 1800Z. By 000Z, those winds are progged to shift to the SW. Upper level winds are unimpressive. The strongest winds (250 mb) level are south of Texas with only winds of about 60 across northern Texas and Southern Oklahoma. The 500 mb are weaker with winds of 40 across the Red River Valley at 1800 Z and these shift to the east later in the day. I do like the change in wind direction: W,SW,SW and SE for 500 mb, 700, 850 and surface respectively. The CAP should be almost non-existant. I am very concerned about the ongoing convection over the Texas Panhandle that will shift eastward. Although some good boundaries may be formed, cloud cover will retard heating.

Right now, I would like to be staying in Wichita Falls, Texas.

Bill Hark
Dec 4, 2003
I'm bothered that the MCS hasn't gotten far into OK / N TX, and new development persists in far E New Mexico. This is really beefing up the cold pool. MAF radar loop at 06Z is showing the outflow surging south like there's no tomorrow. If the MCS keeps putzing around out west then we'll be looking at sucky NE-SW boundary orientations to boot.

Mar 4, 2004
Moore, OK
Ya, tomorrow looks like total suckage. Looks like I will pass up chasing in favor of going to morning class and then heading toward the D/FW area in the afternoon to see the parents for Easter. Who knows, I may have just as good a chance of seeing something heading down I35 in the afternoon as I would if I were out chasing all day.

I will make one last check of the models in the morning to make certain of a final decision. However, attm, I find it hard to believe that anything besides some spotty (only decent) cells will pop tomorrow in lieu of the morning (and perhaps noontime) MCS.

Kevin Scharfenberg

The good news is, the MCS didn't blast a cold pool too far south. The bad news is I don't think it matters. The 6am surface map shows 60 dewpoints confined well south of San Antonio, and there is no mechanisim that far south to start moving the moisture farther north. Every consecutive model run has shown weaker and weaker wind fields over Texas, and this morning's nearly calm winds suggest it is coming to pass. I think the 09Z RUC has the right idea, and dewpoints will struggle to break the mid 50s in central and northern Texas.

I was looking forward to chasing today, but now it looks like a no-go.

Mike Umscheid

I like the I-35 corridor south of DFW, near Waco. Straight west to east 500mb flow around 35 with decent lower trop convergence on the dryline in this area on nose of richer moisture advecting north. Current obs this morning (11z) certainly don't look promising for moisture, thus a south adjustment, I think, would be necessary to realize 2000+ surface based CAPE. Should be a decent push on the dryline (enhanced convergence) around the US-84 latitude. Gatesville to Waco is my pick.... hope it works (I'll be chasing on the D2D today...)

Mike U
Originally posted by Jason A.C. Brock
Hey John

Is that the # for one of the local stations in SPS? If so which one and should I ask for anyone if I see anything interesting? You interested in Tornado reports only?

that # gets you direct to the channel 6 WX center. I would limit calls to promising wall clouds and tornadoes only. Just say who you are and mention Stormtrack.

Kevin Martin

My Analysis

My newly developed Math Analysis for Severe Weather shows a marginal day today. with higher risk being hail, and lower end being tornadic. here is my math analysis. I call it Martin's Law of Weather,lol.


Dewpoint Forecast shows a dewpoint at 62= 50%
Surface Temperature will be at 70 degrees= 40%
Low Level Jet inflow at 850mb will be at 20-25 knots= 25%
Surface Moisture Carrying Wind= 100%
700MB Dry Air Carrying wind= 100%
Upper Level Jet Stream will be blowing at 50 knots= 0%
500MB vort values= 20%
CAPE= 50%

Probability of Severe Thunderstorms is 55%
So with that 55% it corresponds with my charts on........

Severe Thunderstorm Risk.

Type of Event.

Thunderstorm probability is 60%.
no Thunderstorms expected.
Slight Chance
Run For the Hills

HELICITY= 100-150 Weak Torandoes Possible F0 to F1 Damage

Hail values.


added together is 350 or.

Greater than 3/4 inch hail possible!

And now for my discussion

Forecast Discussion.

Surging moisture from the South will result in very high dewpoints in the forecast area today. A dryline will move through the region setting a boundary for Severe Thunderstorms to develop. With CAPE values expected to be in the 2000-2500 range, expect explosive developments. Large Hail will be a large factor, and perhaps the largest threat of the day with these storms. Wind fields don't really show all that much in Tornadic activity, except for Oklahoma City, Northeastward towards Tulsa, Oklahoma, where the highest helicity values will be. If a tornado forms in any of these storms, it will have to be around that area, leaving Northern Texas under a very slim, to nil chance of a tornado, so im leaving that wording out. 500MB chart also shows no signs of fast storm movement, so strong damaging winds within the storms, and bow echo thunderstorms will not be a problem.

Main Concern: Large Hail. Isolated Tornado from Red River to Tulsa, Oklahoma.


Please do check out a map I develop a day before the action hits, and daily updated. My tornado watch, and severe thunderstorms watch, and the very first Tornado Intensity Forecast Map. Should help some of the chasers this spring if they visit the site.
check it out here.

Kevin Martin

Shane Adams

Just completed a detailed analysis of ETA/GFS/RUC data.....and I now have two targets, lol. The first one is the area from Ardmore (my original target town) to Ada, OK. This area's pros include close proximity to the front (and subsequently the best backed surface winds), enhance local helicity, and the help of a decent 850 speed max moving through the area by 21Z. The cons of this particular spot are a potentially severe lack of moisture, bad chase terrain, and the possibility of clouds/ongoing precip messing up insolation. Hope I used that term properly, that's a big word for me :lol:

My second target is Brownwood, TX. Pros of this area are a much better fetch of moisture (especially at h7 per ETA), higher temps, and (if it doesn't mix out too much) the forcing of the dryline (or surface trough as nealras would have it) :D Cons include a lack of surface veering (although any decent storm could back the winds locally), and (per RUC) an indication of subsidence in the wake of (I guess) previous precipitation. UVVs looked good at h5 on the ETA & GFS, but the RUC has a complete void in this region, which to me says "subsidence." But I'm not meteorologist.

I'm leaning towards southern/SC Oklahoma and points east, betting on the front to jack helicities on any storms. However, I'm not commited to either spot at this time. I'm sure the 13Z SPC outlook will heavily influence my thinking, if they're anywhere close to what I've come up with.

Shane Adams

In all my model reading frenzy, I completely forgot to check out a current surface chart. Don't I feel silly now.....
Feb 19, 2004
Oklahoma City
Call me an optimist but I've seen storms tornado in mid/upper 50s dewpoints before. Add in the fact they're going to be crawling around I'm still heading out. i'm adjusting my target to....Velma! Now I'm just gonna sit at home and when something begins to fire per the Satellite, NWS, and SPC I'll head out. I know I'm cheating, but I'm still confident there will be a sweet looking storm today.

Shane Adams

Originally posted by Chris_Sanner
I know I'm cheating, but I'm still confident there will be a sweet looking storm today.

Well, if your target is home - why not monitor conditions and watch for development? That isn't cheating; tons of chasers do this in the field, everytime they chase.

Back to the subject of today - I was pleased with the latest SPC outlook, they pretty much agree with what I'm seeing (though they are understandably more skeptic). Looks like we'll be heading to Ardmore.

Like you said, tornadoes in 50s dewpoints are not unheard of, and everytime I bail on a moisture-lacking, near-front set-up, I get burned (like on May 16 last year). I'm gonna gamble that a storm in SC/S/SE OK will take advantage of the shear/backed flow/helicity near the front and spin....and tornado.
Dec 4, 2003
A big negative - Clear skies all the way south to the Gulf. It's sunny and bright here in Austin with calm winds. FWD's sounding is a huge problem... the mixed parcel yields a surface dewpoint of 50F, and barely squeaks in with what looks like a 300-500 CAPE. Corpus Christi's 64F dewpoint is an illusion because of its limited depth; mixed through 100 mb we get more like a 53F dewpoint and almost no CAPE.

Also lapse rates are poor. It will only get worse seeing as the 12Z RUC is going for 1 to 2C of warming at 500 mb.