5/23/07 FCST: TX/OK/KS

[Donald Giuliano]

Wednesday looks mildly interesting on the 00Z 22 May NAM in southwest OK, with the GFS looking very impressive from southern KS through western OK down towards Hollis. There are pretty significant differences between the two models, with the GFS much slower with the cold front, yielding more of a dryline setup on Wednesday as opposed to the triple point scenario depicted by the NAM before intense LLJ-induced convection explodes overnight along an intense low-level frontogenetical zone. The NAM has a nice bullseye of 8"+ of precip in 12hr between 48 and 60 hours...now I realize the NAM has issues with overdoing convection, but sheesh, someone could be in for some flash flooding if that even halfway verifies.

I haven't had the time to examine things further, and won't until tomorrow, so I don't have any real insights as to which scenario, if either, might be correct. Thoughts?

 

[Donald Giuliano]

This morning's NAM has trended towards last night's GFS, and I have to say I'm very impressed. Monster CAPE, phenomenal shear, and no cap whatsoever, even at 6Z. If we can get initiation during late afternoon, it could be quite the show for some time. Still looking for the models to become more consistent, and where/when/how initiation occurs remains a question, but I'm definitely excited by the NAM's move towards the GFS solution. This has the potential at least to be a very good chase day, as the thermodynamics/shear would be similar to the 4th, if this forecast were to verify.

 

[Jordan Hartley]

The difference between the 2 models is significant Donald. Tommorows setup will be a coin flip scenario as we wont have a good handle on things untill tommorow afternoon. The potential for tornadoes will be there with discrete storms if we can get some cap errosion. Right now I think I-35/I-135 corridor from Salina S to Ict to Perry, Ok could see some interesting action if things pan out right. I just hope storms dont fire too early and we get some garbage mcs mess.

 

[Josh Boustead]

Seemed like to me that the models this morning sampled the 110 kt jet now moving through WA/OR better, and thus the signficant change in the models. Looked to me like the cold front would slip into sw KS tonight as the shortwave over CO passes. Then the front should stall as a new wave of low pressure develops along the front by afternoon. Then that low ejects northeast along the front Tuesday evening. My initial target area is along a Dodge City to Englewood line. Shear parameters get really impressive as that deepening surface moves into southwest Kansas Wednesday evening.

 

[Donald Giuliano]

I am getting increasingly excited about Wednesday with the 18z model runs. The NAM/GFS seem to be converging on a slower, more intense solution, with the instability/shear combination looking equivalent to May 4th (!). Combine this with the likelihood that there will be more storms than on May 4th, and this has the potential to be a very serious event. Still 30 hours to go, but it looks like I'll be taking time off tomorrow for this one.

 

[cdcollura]

Good day all,

Taking time off on this one too. I am leaving Dayton, OH on a 8:55 PM flight to Kansas City and car rental (with full coverage) into Kansas for tomorrow with plenty of time. Heading back to Dayton, OH thursday morning. I will plan on anywhere from around the Dodge City area as a possible "preliminary" target.

GFS showing a pretty interesting surface low by 0z (5/24) which is roughly 5-6 PM CDT on 5/23. Dewpoints at least 65 F, 500 MB at over 60 (maybe 80) Kts from SW, 30 Kts at 850 MB from SSW, SE to ESE at surface, and 80 to 100 Kts from SW to WSW in difluent 250 MB flow. DDC is right under this.

Hope to see some of you guys out there!

 

[Donald Giuliano]

Still looking at an awesome setup tomorrow as per the 00Z NAM. Things appear especially crazy after 00Z, as the environment remains completely uncapped, the CAPE monstrous, and the shear increases to insane levels by 06Z. I am a little concerned about the system slowing down more, which could cause the better shear be completely out of phase until after dark...not good if you want to see daytime tornadoes. However, as things stand now, I can't wait to get out there tomorrow afternoon. Looking forward to tomorrow morning's data/models to get a better fix on where exactly to go--right now I'm thinking maybe Pampa, TX or Guymon, OK.

 

[Jeff Piotrowski]

Significant tornado’s on Wednesday in TX Panhandle, NW OK, and SW KS


Based on 0Z ETA and WRF model the front keeps pushing south in the TX PHNDL in the morning. Then stops around noon from AMA NE toward Woodward then NE from their. The front and dry line intersection point is very close so AMA before the front turns back north as warm front late in afternoon. The stage is set for significant tornados near the triple point and NE along the lifting warm front. The Capes over 4000 J/KG and Helicity over 0-3 KM 400 over the northern TX & OK Panhandles NW OK.

The wave approaches late in day with over 50 Knts of SW flow over the northern TX Panhandle. The surface winds backed to 130 25Knt’s 850 jet over 50 Knts is setting the stage for long track tornadoes before and after dark across NW OK, SW KS, and NE TX Panhandle.

 

[Bob Schafer]

The surface winds backed to 130 25Knt’s 850 jet over 50 Knts

Where do you see this, Jeff? I have a problem with the progged parameters, at least at 00Z on the WRF. I see sfc winds of 10-15kts

http://weather.cod.edu/forecast/ETA/SP/etaSP_2_temp_24.gif

and 850 winds slowing to ~25

http://weather.cod.edu/forecast/ETA/SP/etaSP_850_spd_24.gif

as they approach the CF. With sfc low wimped out at 1000mb...barely...

http://weather.cod.edu/forecast/ETA/SP/etaSP_2_temp_24.gif (again)

and storm motion NE at ~10-15kts,

http://weather.cod.edu/forecast/ETA/SP/etaSP_1km_hel_24.gif

the storms will be starved.

 

[Jeff Snyder]

Bob: I think Jeff is referring to the 6z forecast in places, which shows >55kt 850mb flow in the warm sector ahead of the front and dryline. 0-1km SRH above 200 m2/s2 is very good.

I am optimistic about the potential for a couple of significant tornadoes tomorrow in the northern TX panhandle, OK panhandle, and maybe far southwestern KS. The best midlevel flow gives a glancing blow to the warm sector. It looks like the post-frontal winds will veer from the E to the SE through afternoon, particularly northwest of AMA, which will draw moisture northwestward towards far northeastern NM. Meanwhile, strong instability will develop in the warm sector as shear profiles strengthen. Personally, I like the area near a line from Pampa to Perryton as a starting point. I hope to see a supercell develop near Borger or Dumas by mid-afternoon that moves northeastward and is located somewhere near Beaver OK by sunset. The cold front slams southeastward after 03z as the surface low moves quickly / redevelops northeastward from east-central NM to the eastern OK panhandle.

As mentioned, the 0z NAM currently shows 45-60kt deeplayer shear north of I40 across the northern tX panhandle by 0z tomorrow evening. As the LLJ intensifies significantly after 00z, low-level hodographs lengthen and conditions become quite favorable for strong tornadoes. It's worth noting that the GFS is farther north with the front tomorrow afternoon across the northern TX panhandle, potential owing to precip cooling the post-frontal airmass in the NAM output. Regardless, the GFS would suggest a target a little farther north, perhaps near Guymon as a starting point.

I wouldn't be surprised to see the MDT pullled a little farther southward, closer to Pampa and AMA. I'm slightly concerned about the lack of CINH in model-land, as well as storm mode after 0z as the cold front marches southeastward (along a line from Salina to Woodward to AMA at 6z per GFS; Hill City to Guymon to Vega per NAM). Prime tornado time appears to be in the 00z-03z timeframe (which isn't uncommon).

 

[Michael O'Keeffe]

I'm heading to SW KS this go around mainly because I'm restricted to that area today. I am confident this area will also produce along with the Panhandles. I am pretty sure an OFB was set in place since storms moved through last night. If a storm could fire along that then we could have a tornado. So my target as of right now is Coldwater, KS, but will most likely change. The RUC us indicating CAPE to 3500 j/kg in this area and i want to be right on the tongue of it just like May 4.

 

[Brian Swiatowy]

Well, the front made progress farther south than just about any model indicated (the NAM being the closest). It has since pulled up nearly stationary and should start going back north here in the next hour or two. I'm guessing the MDT risk area will be farther south and maybe a little west for the morning update. Triple point placement will be key this afternoon, but I think I'll be able to stay pretty close to home (AMA) for storm initiation. There should be an awful lot of spin in the atmosphere this afternoon. Hopefully we won't see a repeat of the Tulia/Cactus tornadoes we had back in late April...but it does appear to be a possibility.

 

[Wesley Luginbyhl]

For those who are going to chase the panhandles this afternoon, here is a page that might be helpful in finding the triple point location, http://www.kvii.com/weather/school_net.aspx. You can change the variables to whatever 2 that you want to see.

I definitely woke up to some cooler air here in Borger this mourning. If the front being this far south is a sign the NAM is closest to being right, it could be a very long day for the panhandles. The fronts location at 7:45 this morning is from Dimmit to Clarendon to Canadian in the TX Panhandle. That is only about a county south of what the NAM said, so the NAM really isnt far off so far.

 

[Matt Hines]

The front is still pushing south at this time and has now passed Tulia, TX on its way to Plainview, TX. The front will lift north today, but my thinking is it will only make it to I-40 or just north. With that, agree with Brian that you should not have to go too far from AMA today to catch something. We will see if the 12z runs pick up on the front being father south this morning. Triple point will likely set-up near Clovis and the Texas state line. Could be a very long day!

 

[Andrew Pritchard]

Well, hard to pinpoint a target now. Sitting in Great Bend, KS attm, so we'll likely just start heading sw. Area around Pampa to Childress looks pretty prime. The front is supposed to stall and start retreating a little, and then form a nice kink/bulge right around that area and I think this is where we may see the storms of the day. Things may wait til later in the evening today until the llj really cranks it up. It's fairly weak for a good chunk of the day from what I can see.