3/23/07 FCST:West TX.

[Rocky Rascovich]

Greetings! Pouring over data from several different models has lead me to look further into a potential trip to west TX. for Friday. I'm guardedly optimistic that isolated to scattered supercells are possible, best chances according to both the GFS and WRF will be in the general vicinity of FST to INK for Friday afternoon/evening period. I have concerns with a couple of monkey wrench's thrown at me such as too much cloud cover limiting insolation, I don't see capes being much over 1500 j/kg onless we can get some clearing during peaking heating. Also, I noticed on both the GFS, WRF and SREF that low level flow will be minimal, although the shear from the 850mb-500 looks acceptable. PW's look pretty stout, so potential is there that we'll be dealing with some excessive rains... which they can use every drop. the primary focus for this potential chase will be for some picturesque storm structure, perhaps a needle in a haystack tornado for this day.

I'm waiting on some fresher data to solidify my reasons to head into the hinterlands of W. TX... will it be worth it??
Edit: Meant to insert the "FCST" heading to this, sorry.

 

[Robert Edmonds]

I remain speculative, and will likely make a decision tonight as to whether I'm going. I feel there is sufficient shear however I’d prefer stronger cape values. It would be nice to hear others thoughts on this day. I’d write more but I’m in class...

Edit Perhaps Eastern NM; should also be included in this thread???

 

[Reed Timmer]

The 00z Friday WRF analysis is substantially underestimating dewpoints!! In the initialization, the 60F line is just northwest of Austin, TX, with 55-60 dewpoints analyzed everywhere to the northwest, including Del Rio, Junction, Abilene, etc...It appears that the WRF initialized as much as 5F too low. I'm thinking CAPEs will be much higher over southwest TX on Friday.

If the GFS wind fields verify it looks very favorable for tornadic supercells...if the WRF low-level wind fields verify, we might be in trouble.

I'm heading out regardless.

 

[Rocky Rascovich]

Looks like I'll be doing another virtual chase from the farm on this one. Being I was looking at an almost 400mi. trip to where the action MIGHT be, the chance of all that driving and yielding nothing more than what I'm experiencing here at the farm now; heavy rain with frequent CG's. Its best I wait for a more favourable setup.

The con's, potentially too much cloudcover limiting instabilities and low level winds are meek according to the WRF as Reed stated. Surface pressures will be barely adequate as the low starts to lift into the southern high plains. Upslope winds from the E and SE should compensate for that in the Ft. Stockton/Pecos area along with capes averaging around 1250j/kg.

Being I'm not going now, all hell may break loose. For the more data challenged folks heading out, I'll try to be here to take calls if you need some guidance. I have wx-tap and most other data sources Home phone: 405-373-5097

Rocky&family

 

[Tim Marshall]

TARGET: MIDLAND, TX TIME OF DEPARTURE: 10 AM - Agree with SPC on the higher probability of severe for SW TX and SE NM today and will head out I-20 at 10 a.m. PROS - Plenty of speed shear here and with southeast winds at the surface the directional shear is not bad either. I like the clear skies on satellite out there and overnight convection has remained north. Anticipate storms will fire in the clear air and then race north-northeastward. CONS - Low-level moisture is not great and with strong winds aloft, storms will be racing north-northeast over a difficult road network. I don't see a boundary either (i.e. no dryline/focal point) but perhaps a bit of drying will occur southwest as the air descends over the Davis Mtns. Looking for a right-turner out there. TM

 

[Bob Schafer]

I'm not sure I agree with Tim's view that low-level moisture is not great. MAF's sounding: http://weather.unisys.com/upper_air/skew/skew_KMAF.html

Did Tim forget about the elevation in those parts and W of there? IMO, that's incredible, deep, moisture for W TX/SE NM for March, and he may not have had an opportunity to see the Skew before his departure.

What did concern me about the sounding was the high-level cap from about 770-650mb. Then I had a look at the latest 700mb data, and temps in northern Mexico are cooler than at MAF (at least @ 1200Z), and advecting NE.

There are plenty of orographic features to facilitate lift...

I think I have to agree with the MDT! Good luck to all chasing out there today!

 

[Reed Timmer]

As expected, the 12z WRF solution has shifted towards the GFS...given the erroneous analysis of last night.

The RUC is predicting 3000+ CAPEs over se NM and sw TX....and low-60 dewpoints are huge as far west as se NM. 0-1 km hel of ~200 in that area are nice too, but as Tim mentioned, we're going to need a right-turner.

Does anyone know what's wrong with the WRF initializations these days??

 

[Gabe Garfield]

Starting to get a little excited about the possibilities today. Looks like, as Reed mentioned, Tds were severely underanalyzed by the WRF leading to paltry CAPE values. I was fully prepared to blow off today, but now it looks as though at least moderate instability should develop and a chase looks to be in order. As of now, I'm targeting the boundary that extends from Clovis to Plainview. Hopefully, it will maintain its identity through the day. I expect this boundary to drift northward on continuing southerly flow.

Target: Hereford, TX

Gabe

 

[Bob Schafer]

I think it's noteworthy that the 15Z RUC now progs CAPE >2500 all the way into the PH @00Z, and >3500 to near FST.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/ruc/hr4/images/ruc_cap_009m.gif

 

[Jason Boggs]

I think the RUC forecast of 3000+ CAPE is way overdone. I think CAPE values of 1800-2200 are a fair estimate in the threat area. I hope the sun can come out and do it's magic in the next few hours. I'm looking to start out near the Dimmitt Muleshoe area and go from there.

 

[Matt Chatelain]

Curtis McDonald, Daniel Betton and I are targeting the Hobbs, NM area for intitiation of supercells around 21-22z as the ruc is forecasting. We are anticipating main threat to be large hail producers early on in the event and right moving supercells after 0z with a tornado threat as 850 winds increase and storms move into deeper moisture.