3/30/08 FCST: OK/TX

[Wesley Luginbyhl]

If this is not a far drive for you, then it should be a chase IMO. The 12z RUC 3h precip will give you some more confidence in today if you trust it. It has what looks like cells from NW OK down to the Abilene area even. The RUC also showed an area of 3500 CAPE around Lawton at 00z that was capped, but just to the west of that was an area of no CIN. The 12z NAM looks to keep the precip north of I-40 still atleast before dark. It looks as though that some storms are going fire right at or just before dark. I feel that we may even get a few hours in before dark considering the way the models have handle the cap recently. Triple point still is the best option at this point to me, but we will see as the day progresses.

Edit: Jeff beat me to it.

 

[Jason Montano]

OK, the RUC has precip breaking out by 21z as previously mentioned. I am pulling the trigger and heading to SPS. If the convection that is progged to develop there around 21z can hold on until 0z some mid/upper level support comes to the rescue. The h9, h8 begin to back and the h7 winds pick up some. The h5 flow is still a bit weak but it's worth a shot. What I also like about this area are the backed sfc winds reaching 15 knts.


Good luck to all heading out!

 

[Shane Adams]

I agree the new RUC *looks* encouraging, but as has been the trend in 2008, the RUC is on crack. Look at the runs for current time and a few hours from now and then compare that to radar....there's nothing out there. I got burned early in the year on a RUC precip forecast and have taken it with a grain ever since...I've done a lot of these 'real-time' tests and it's failed miserably much of the time.

I'd be weary of basing a target/plan based solely on RUC precip runs.

 

[Dustin Wilcox]

FWIW nobody will be chasing today, myself and some highly trained Meteorologists have determined based on our analysis that everyone should stay home...

On a more Serious note am pleased by the trends of this mornings RUC, though it pushes the target a little farther south, further from the stronger upper level support, though I still appears to be sufficient for some dear dusk initiation and ultimately some ragging supercells by dark.

 

[Gabe Garfield]

I agree the new RUC *looks* encouraging, but as has been the trend in 2008, the RUC is on crack. Look at the runs for current time and a few hours from now and then compare that to radar....there's nothing out there. I got burned early in the year on a RUC precip forecast and have taken it with a grain ever since...I've done a lot of these 'real-time' tests and it's failed miserably much of the time.

I'd be weary of basing a target/plan based solely on RUC precip runs.

I quite agree, Shane. I've never been a big fan of the RUC QPF, and the NAM still doesn't produce precip by 00z. That being said, the fact that the NAM doesn't produce precip doesn't necessarily mean much; it said as much before Thursday's supercell bonanza in OK/MO.

That being said, I am happy that the RUC produces precip over a broad area, and in the right areas (along the dryline to the triple point) instead of the free warm sector (as was the case in last night's NAM). Also, the QPF amounts are fairly substantial, suggesting that the RUC might be picking on up on a real atmospheric cause for initiation. I suspect the difference between the NAM and the RUC may simply be in how much CAPE each model generates. The NAM is slightly chintzy with its development of instability, while the RUC (as usual) is going gangbusters with almost 4000 j/kg of SBCAPE. If the RUC is out to lunch on the CAPE forecast, I'm going to start getting concerned.

 

[BrandonWhittington]

As of right now, i still look to be chasing this evening and tonight. I want to be in western Oklahoma somewhere when the LLJ kicks in. I really like the setup and there is no need not to chase, close to home....... Im starting to lean a little further south than i first thought of. It was woodward, but now its more like gage down to clinton line,.....We will see, moisture is here, and the surface low has already developed in the the far easten part of the Oklahoma Panhandles........

 

[Mikey Gribble]

Just wanted to echo the other comments on trusting the RUC QPF. I trust that thing about as far as I can throw it. I don't really trust any model on precip., but the RUC is at the bottom of my list if I have to trust one of them. That being said I'm going to contradict myself and say that I do think we'll get a storm going near the triple point before dark or right at dark. I think the best bet is setting up East of the triple point. I am still looking at Enid as a good initial target. Still haven't finished my morning forecast yet though so that could change.

edit - The RUC also has 850mb winds in the 15kt range at 00Z.

 

[Tim Marshall]

If I could chase today, I'd definitely head out -late show or not. My target would be Sayre, OK based on funneling of surface moisture into that area by 0z. There should be ample clearing of the low clouds out there that will help heat things up. Sure, I am concerned about the convection farther to the east, the capping inversion west, and timing of the upper air trough (main axis is still a day away), but I wouldn't want to be sitting at home when the first T-warning is issued tonight -unless of course I lived in Sayre, OK.

 

[afischer]

Model concensus is for the triple point to stall near/southeast of the Amarillo area, with a diffuse dryline organizing/mixing eastward through the southeastern panhandle/eastern south plains. MAF and AMA show 7C at 700mb this morning, which is a little toasty considering uncertainties regarding whether deep/rich moisture will back all the way up to the dryline by 00Z. NAM and RUC show 2000-2800 MLCAPE developing later today in an axis ahead of the dryline, which is pretty nice. My confidence in how convective initiation will play out, as well as whether low-level thermodynamics and low-level shear will support tornadoes before sunset, is pretty low. Also, I'm afraid any tornadoes that occur after dark may be embedded in stratus clouds. I have stuff going on today, but could chase tonight... I'm up in the air at this point.

 

[Angie Norris]

If I could make it out today, I'd heading to Cherokee, OK. Winds look to back nicely by 0Z (there appears to be an outflow boundary in the area ATTM with NE winds per the obs...another good thing), moisture is definitely in place.

Everybody be careful and good luck...

 

[Jay McCoy]

As dry as it is in the panhandle the dryline will mix rapdily to the eastern border. Stronger lid to the south but with better instability compared to weaker CIN and weaker cape north then play the middle so I-40 just east of the state line it is.

I do think we will get some initiationa few hrs before dark (22z). I was 1st worried about cloudcover but most of western Ok is nice and clear allopwing max heating and wiht a sharp dryline and a strengthening LLJ I expct a few nice cells before dark.

Target: Eric-Elk City area with an eye to the south.

 

[Kenny Drake]

What I am worried about anywhere across the potential initiation regions at this point is the RUC forecasting meager 850mb winds at dark after they back to the south. I think the PBL may decouple rather quickly if that is the case. Regardless, I think we can get initiation at or maybe an hour or 2 before dark. There will be a narrow window for enhanced tornadic potential and then things may get elevated rather quickly. Personally, I just love convection so elevated or not I'll be out (with Eddie Natenburg more than likely.) We haven't looked at details yet as to a chase target but at this point it looks like I-40 West from OKC is looking juicy. RUC is progging the triple pt to be across W. OK near I-40 by 0Z. Strong moisture advection and backing sfc winds beginning just before dark should help the dryline seemingly "move" west rather quickly after dark. This doesn't mean convection is not going to keep firing after dark all along the warm front as I think it will. All in all an interesting evening and night should be in store. The sun is shining and I see a nice Cu-field across W. OK (as of 11:45am vis sat) in response to what looks like a s/w via w/v imagery. The instability is there for later this afternoon and the CAP will most likely break at or just before dark assuming the RUC pans out. Daytime heating may be enough to get some HCRs (Horiz. Convective Rolls) going as winds are already at or above the accepted threshold of 5.5m/s (~12mph). If these occur then I would pay very close attention to them as possible sources of convection ahead of the dryline.

 

[Jason Montano]

The 1630z outlook from the SPC is a little discouraging for my target of around SPS. However, per RUC 16z runs it still looks pretty good to me. Granted it is on the south side of the dryline bulge and the h5 winds are about 5kts slower, but RUC still has precip breaking out in that area. Anyone have thoughts on why SPC left this area out of the SLGT risk cutting it off sharply at the Red River?

 

[Mikey Gribble]

I just updated my forecast here...
http://loadedgunchasing.com/blog.html
After looking at forecast soundings I am afraid that any convection that gets going will struggle with the cap. I also don't like the short hodograph, so I am probably going to sit this one out. If I was chasing I would target Watonga. I think the Clinton to Enid corridor holds the best tornado potential in the 02-06Z time frame. Good luck to anybody who goes out.

 

[Jeff Snyder]

Not sure what to think of the very veered sfc flow in western OK attm, as I'm not sure if it's a sign that moisture is being depleted in a top-down fashion. The 15z RUC depicts this veered flow well in its 3 hr forecast (valid 18z), and it backs that flow to S then SE by 00z. However, it is still maintaining anemic 850mb flow in northwestern OK until 3z, which continues to make me nervous over daytime supercells (much less daytime tors). The drier air starting to advect into or mix down from from above in NW OK is likely the culprit for model forecasts of weaker CAPE in the NW 1/4 of OK later today, with the 00z NAM not showing much at 3z very far N of I40. As it's looking now, I think my "wait and see" target is somewhere near Elk City, though I hope to see the veered flow begin to back before I commit there. Regardless, such a location along I40 gives a decent N-S option for adjustment. The sfc cold front is farther S than I had anticipated it would be yesterday at this time, showing up reasonably well on KAMA 88D... 12z NAM shows maximum convergence in the east-central TX panhandle at 00z near the 'new' triple-point established by the then-stationary front and the confluence line / DL established as winds back in far western OK late afternoon and evening (see here).

12z RAOBs showed very steep mid-level lapse rates across much of the area, including nearly a dry adiabatic layer (>9 C/km) between 575-800mb at DDC and between 600-800mb at AMA, which is nice to see. Even better to see is the 20-30kt storm motion in March (which would be fine in April as well). Latest HWO from OUN seems a bit more optimistic, noting the possibility of a "severe weather outbreak" later today.