4/16/09 FCST: KS/OK/TX/NE/CO

[Andrew Stoller]

If this next system can give Texas/Oklahoma some more much needed rain, and then if the models verify with a ridge in the west for close to a week, that might be a good thing because it'll open up the gulf when a new trough develops.

We're still dealing with front after front cleaning out the northwestern gulf. A week long break with no systems and no pacific fronts might be just what the doctor ordered to solve the moisture return issues we're having.

 

[Jeff Passner]

Actually, Thursday does not look THAT bad. Clearly, moisture is an issue again and this is no surprise given the brutal winter and the large number of southern-stream systems that have dropped dew points into the 40s in the northern Gulf. Still, I see a possible "target" based on the latest models. Perhaps, the area NW of ABI will be "okay." There's a highly-diffluent 300-Mb pattern between the polar jet and subtropical jet and pressure drops near DHT. An 850 wind of 20-25 knots is acceptable. One thing that might happen is some storms forming Wednesday night and Thursday morning in the LLJ. This area moves off to the east, and might leave an outflow boundary in west Texas somewhere. I agree that flow up the Caprock will enhance storm formation late Thursday. Given the reasonably cool temps and a 55-60 dew point, the LCLs won't be that bad. Shear seems adequate for rotating storms. Wave timing is an issue and impossible to forecast right now, but a weak vort lobe coming around the base of the 500-MB upper low might help things out. Lapse rates looks a little weak, but it will be interesting to see how this one evolves. Given the choices so far this April, I'm not that down on Thursday yet.... Beyond Thursday, Yuck ... Weak surface winds and large-scale rain in Texas makes chasing prospects look bleak Friday-Sat, although I would not be shocked to see severe weather and perhaps an isolated tornado or two on Friday, but that's for another thread.

 

[Matt Hughes]

If this next system can give Texas/Oklahoma some more much needed rain, and then if the models verify with a ridge in the west for close to a week, that might be a good thing because it'll open up the gulf when a new trough develops.

We're still dealing with front after front cleaning out the northwestern gulf. A week long break with no systems and no pacific fronts might be just what the doctor ordered to solve the moisture return issues we're having.

I am in total agreement with you Andrew. At this point I don't see a whole lot to be excited about with this system except that there will be some weather/gustnadoes to chase. I would glady exchange a week or two of quiet weather to open up the gulf. The systems this year have been so dynamically impressive thus far but have basically all gone to waste. If we can get the moisture return and more of these systems to roll through a little farther apart then the rest of the season could be memorable!

 

[Mickey Ptak]

Not much to say at this point in time but I sure hope things look better in next few runs ...

One thing that is a plus in this case is the fact that it is setting up over the Caprock. Mid to upper 50s Tds can do the trick when taking elevation into consideration. That has been evident in many cases such as 5/12/05.

The flip side, unlike 5/12/05, is that instability at this point in time is so limited and shear IMO may not be sufficient to over come the lack there of. The storms have such a narrow band of instability to work with I see no chance of a supercell sustaining itself for any extended amount of time. Much less long enough to produce a photogenic tornado.

I think if all holds as is, we might see a supercell but I think any storm(s) that fire will quickly turn into a messy mush.

I am sure I will still take my chances if things even slightly improve in future runs.

Mick

 

[Tony Laubach]

If the powers that be would graciously add Colorado to the mix, I would be most delighted...

I think a good secondary target is going to be in eastern Colorado and points just east into Kansas. Been watching this system's potential close to home for several days now and feel as if there is a possibility to see some interesting storms in the higher terrain.

While the overall instability profile isn't great, the mid 40s dews with 60 degree temps keep spreads fairly reasonable. The NAM does approach 1000J/kg of CAPE across the area with very high values of helicity along and near that front. Good upslope will be in place and that should aid in storm development beneath a very nice shear profile. Hail is almost certainly possible, but a few spouts are not out of the question given the low level helicity values that should be in place across northeast Colorado.

 

[Michael O'Keeffe]

As for the Texas target, it continues to trend better and better. The CAPE and instability which have been my main concerns are slowly getting better with each run. The 4KM WRF precip breaks out no precip in the morning and a few nice sups by 22z. Moisture will be fine with 55F+ dews, and instability with be 1000+ j/kg over a fairly wide area. I would like to see at least some pockets of 2000 j/kg and maybe some higher SRH values but the 0-1km which I think is very important is not bad with values between 200-250 m2/s2. The veering wind profiles are trying to work themselves out as well, with a SE LLJ, SSW 500mb winds, and the 0z NAM had more SW 250mb wind.

Though I'm still on the fence I'm not giving up on this setup as it is in an area notorious for doing amazing things with little to work with and the models are continuing to improve.

 

[Stan Rose]

Colorado should be added to the mix. The SPC is justified in mentioning a low tornado threat for ern CO. latets NAM is a bit sparing with the low level moisture, i dont really see upper 40 dews as far north and west as the boundary from the Palmer dvd to Limon, but the winds should be pretty well backed up there. moisture might be better farther E/S closer to KS. Anyhow, a decent low CAPE-high shear setup, although any storms are probably gonna be racing pretty well to the north. If its not out of the state, ill probably take my chances with it.

 

[Brandon Lawson]

If the 00z NAM can verify, I'd say tomorrow actually looks half decent over the Texas Panhandle. My biggest concern would be timing of initiation. If storms go up too early, then it's over. It would be nice to have an area of clearing to bake under the sun for a few hours. Mid 50's dewpoints seem possible on the southern end of the target area. I'm hoping moisture trajectories will be able to pull in the better moisture currently in southern Texas. This moisture will also benefit from the Caprock. NAM is showing relatively good LCL's all along the dryline in Texas with a slight bulge south of Amarillo. Mid-level winds are fairly meridional, but improve slightly as you get south of I-40. If storm coverage is not widespread, perhaps it will be possible to maintain a few discrete cells. Any areas that can achieve AoA 1000J/Kg of CAPE would have a small tornado chance as well, per forecast soundings that show good low-level veering. Overall, the NAM is painting a nice target from around Amarillo to Dickens, Texas. I plan on getting up in the morning to look over everything one more time, and then heading out.

 

[Bill Hark]

I am cautiously optimistic for Thursday, April 16th. I like the backed surface winds from a low in SE Colorado south into Texas along with the SE winds at 850mb per the 00Z WRF. There will be 50 kt or above SW winds thorugh a large proportion of west texas especially south of Amarillo to the Mexican border with a hint of divergence. Dewpoints will be a bit low (55-60 at best) through west Texas and 65 in far south Texas with marginal CAPE to 1000. Helicities are forecast to increase though best after dark. I would have a tenative target of Midland, Texas. I see the slightly better winds to the north but I am picking a southerly target for better moisture. There should be some pretty evening supercells which will hopefully form just before dark. Tornadoes are less likely but possible especially after dark. If one does develop just before dark, I think there could be some nice photo oportunities. Some of the prettiest tornado images that I have seen are relatively weak ones from high-based storms.

Bill Hark

 

[Jason A.C. Brock]

Shut up and chase time

This isnt the best setup for a huge tornado outbreak but nice structured supercells near sunset is enough for some good pics and timelapse so Ill be headed for Happy Texas. Dews could be high but after seeing tornadoes on the caprock with 50s dews before ya wonder what surprises will arrive there tomorrow. If nothing but a nice little squall line to take pics along of the lightning on the ride home. Get ahead of the line....snap snap ....drive.......stop snap snap snap driiive snap snap....you get the idea. Dew points already in the 40s and no substantial precip has formed out west yet. It may soon but some better heating along the dryline than we think could occur somewhere between Amarill and Dickens. Ill go with a Amarillo to Dickens to Childress triangle.
Some nice sunset sups hopefully. everyone stay safe.
Jay
Watch out Labauch....I wear cowboys jerseys ...but not tomorrow

we will be doing updates tomorrow AT WWW.HOLYTORNADO.COM & http://WWW.YOUTUBE.COM/SHADOWCHASER777 ALSO STORM CHASER MAN ON TWITTER AND USTREAM
AS WELL AS WWW.MYSPACE.COM/HOLYTORNADO777

 

[Tim Marshall]

Chase forecast

TARGET: SWEETWATER, TX TIME OF DEPARTURE: 11 AM I agree today is a marginal chase day, but all I am after is a lone supercell. PROS: A closed off low is approaching the four-corners area with jet max rounding the base of the low. RUC forecasts 50 knot flow across Midland by 21z and southeast surface flow at the surface makes for significant shear. I like the clearing on the morning satellite image in SW TX and believe that storms will develop along the dryline in the BGS-SNY area and move northeastward to Sweetwater later today. Low level moisture, while not the best, is better than with the past few systems. At 13z, mid-50 dewpoints are in place from Snyder to Midland with higher dewpoints farther southeast. That's ample enough for me. CONS: It remains early spring according to Mom Nature. The "good" moisture is confined to a narrow ribbon south of Corpus Christi. Low-level trajectories farther north are too dry and dry air lingers over the northern portion of the Gulf of Mexico. I don't much like, slow, stacked lows as not enough cold air aloft moves over the warm sector, so instabilities remain low. CAPES will only be 1000 to 1500 j/kg in the target area. The 12z Midland sounding also shows a significant cap.

 

[Andrew Stoller]

Today could really be a sleeper day for eastern CO near the surface low. The shear profile is almost identical to May 22, 2007 (ie the Windsor tornado), with due easterly surface winds and south south easterly at 500mb, although the system isn't nearly as dynamic.

Dewpoints are already in the mid 40s from Limon to points southeast, and the RUC is forecasting up to 2,000 J/KG CAPE by 00z, with 1,000 to 1,500 from 2000 to 2300.

If 50 degree dews could materialize, with the very strong shear in place near the surface low in south central CO, I wouldn't be surprised at all to see a tornado or 2.

The NCEP 4.0 WRF breaks out what almost looks like a string of pearls line of lower topped, northwestward moving supercells from about Lamar to Limon CO.

 

[Kiel Ortega]

Not too much to add beyond what's already been said here. Currently north of Childress and heading south. Right now the play looks to get food and then head for the clearer areas down around LBB and points south. Major concern for me right now is how far south will all this elevated stuff currently lining up along the TX/OK border and then to the south will affect later today; if it continues to build to the south and continues for the rest (or at least a good part) of the day it will probably block the moisture from getting into my current target area and cause some problems for my convective hopes. If it doesn't interfere that much, given current 15Z RUC output, looks to be some good play off the dryline bulge in the CDS-LBB-SNK area with moderate instability and shear.