2019-05-23 EVENT: NE/KS/OK/TX

[Dean Baron]

Thursday has been on my radar for a few days. SPC has it highlighted in their day 4 outlook. Looks like we will have a warm front draped across the NE/KS border by Thursday afternoon/evening and a dryline/cold front across western KS. Forecast soundings show quite a bit of shear along the warm front with 0-1km SRH in the 200-300 range with 30 knots of shear and 0-3km SRH over 400 and perhaps over 500 if you cherry pick the soundings and 50 knots of shear. Instability doesn’t look to be crazy but forecast soundings show solid MLCAPE values of 2500-3000. Combined with low LCLs it could be a decent set up. It’s outside the range of the CAMs right now. It’d be nice to get an idea of what they are thinking for storm mode and evolution but we’ve already seen this season that the CAMs don’t always get it right anyway so it might be a moot point. NAM is much more bullish on the parameters than the GFS is, although that might just be a resolution different between the two because the GFS is still throwing out some decent forecast soundings. It’ll be interesting to see the day 3 in the morning. If the NAM verifies it could be a pretty good setup on Thursday. Curious to get anyone else’s opinions.

 

[James Gustina]

The only potential qualms I have with the amazing parameters on the triple point are the storm motions. I'd very much bet on tornadoes in N KS/SW NE but storm motion in the 45-50 knot range perpendicular to the warm front has me worried about the viability of the TP for more than a brief show. Further down the dryline, the NAM and GFS have much more manageable storm motion vectors but both models (in particular the NAM), show a hint of backing around 3KM along with slight height rises/warming in the mid-levels . Regardless, I'd be very surprised if both potential targets don't see supercells, with the NAM and GFS progging >200 m^2/s^2 of 0-3KM SRH and MLCAPE values exceeding 2500 j/kg in most area from the surface low south along the dryline. The consistent signal of mid-upper 60s dews pooling along the dryline in the vicinity of Dodge City and it only takes one mesoscale feature this time of year to set off something good in that kind of environment. Hope to see everyone out there on Thursday!

 

[Dean Baron]

12z NAM has come in and it is keeping the warm front farther south that previous runs and places it more in central KS. Probably out of range for me for a one day trip unfortunately. The set up is within range of the 3km NAM and it doesn't paint the most promising set up. Still some maxed out parameters but it isn't showing many big, healthy, sustained storms on reflectivity and this is also reflected on the UH tracks. Forecast soundings show nicely backed surface winds but right now there is some VBV in the lower levels. The set up is at the end of the range for the 3km NAM so things might improve once it gets a better handle on things. The NAM is still showing nicely curved wind profiles along the warm front. Deep moisture and low LCLs (500-700m) could help compensate for some issues with the set up.

 

[Warren Faidley]

Any chance of the Mods adding TX to the thread? (45-60 kts. bulk shear and capes of 2500+ j/kg forecast). Areas in central and / or NW Texas Panhandle southward could have potential (structure, LP's, big hail and brief tornadoes) *if* the stout cap is breached. Some models, including today's 12z NAM hint of VBV issues below 700mb at 18z. We are also entering the time of year when models often underestimate the westward extent of moisture return. Not a perfect day, but even "perfect" days can go bust.

 

[JamesCaruso]

Flying to ICT this evening to start my chase vacation, meeting up with my chase partner there who is flying in from AZ. First leg to Chicago was delayed and I would have missed my connection, so I changed to a DFW connection. If something goes wrong I can always start out from there just as easily.

Plan is to head west from ICT early and reevaluate N/S extent from there. Didn’t have much time to forecast today but a preliminary look just now while at the airport will have me targeting the triple point in SW KS or south into the OK/TX Panhandle. Confused as to why GFS does not show as much CAPE in KS as in the TX PH given its temp/dewpoint profiles. Also confused as to why it maximizes the supercell composite in the SE TX PH - it has CAPE higher in that area but dews are similar to the north and wind profile looks better to the north. Is convection north of the front responsible for this? NAM similarly shows max CAPE in the TX PH (supercell composite maximized more toward the NE TX PH) and almost no CAPE in KS but that makes more sense because it shows a cold front looking cool air intrusion into SW KS. As @Jeff Duda pointed out in the 5/20/19 thread, the “GFS is notorious for undergoing the extent of cold air” so I guess I should favor the NAM and bias south toward the TX PH but can figure that out in the morning.

 

[JamesCaruso]

Quick check of 0Z models upon checking into my hotel in Wichita after a long day of traveling for work and then out here... GFS has come in line with NAM showing cool air sagging southward from SW KS, but doesn’t bring it all the way into the northern TX PH like the NAM. Both models hint at a dryline bulge at a latitude a little south of AMA, further west on the NAM. HRRR shows a NE-SW oriented line of UH with a nice tail end Charlie a little east of AMA. Could be a tough target area forecast, need to get south of the (outflow reinforced?) cool air but the cap is stronger as you go south. Will be heading SW out of Wichita pretty early and will forecast on the road.

 

[Warren Faidley]

Nothing like an extended period of sloshing dryline days over some of the best chasing real estate in the Alley. Typical, late season dryline forecasting with a smorgasbord of fun and exciting monkey wrenches and atmospheric brain teasers. There will likely be a very small window for tornado development with any supercell before they line or cluster out. GOES shows nice clearing near the E NM border, so will likely target that region, for the first round. Very impressive DP's for this region, so LCL's are quite low, which could make things very interesting.

 

[Jeff House]

At 1pm central, clearing is noted both sides of WF in northern Oklahoma. That's a bullish sign usually. Did not happen Monday. Did happen Wednesday. Let's avoid population centers this time.

We are lunching in Woodward. Trying to avoid dot advection on I-40. Believe DL intersection with WF or OFB has a legit chance now, with clearing both sides.

 

[Dan Robinson]

Uncomfortably cold and strong NW winds behind the boundary over AMA now, even though it looks to have stalled/is in the process of stalling. Don't like seeing that strong of a push on the cold side. A little outflow from a storm and it's going to start moving southeast quick.

 

[Dan Robinson]

Thinking this day is already done for in the Panhandle. Storms going up behind the boundary will only help reinforce it, and storm motion is taking cells deeper into the cold air. No sign of CI southeast of the boundary except SW of Lubbock and up near Perryton. The northern environment has been and still is socked in with clouds. The southern storm has a more favorable trajectory, but is moving into 700mb temps of 12-14C - it may struggle to maintain.

 

[Quincy Vagell]

Storms will be initiating along an axis that nearly parallel to the deep shear vectors (W TX/TX PH). They’ll probably line out rather quickly. Storms near the warm front seem to be just blowing past the warm front.

It‘s not over yet, but I can’t help but struggle to find a particular target that looks solid right now.

 

[JamesCaruso]

Agree with Dan and Quincy. Adjusted initial target of Dimmit and dropped south to Plainview to stay southeast of the front, which is where we are now. LBB AFD says Parmer County (Friona/Bovina) has best chance of tornado but those storms are behind the front, that’s the whole reason we deviated south. Winds have backed and strengthened in both LBB and PVW but there is not a lot of convergence - as also noted in LBB AFD. The dryline is quite diffuse. Not interested in storms to the north moving along that boundary and on the cold side to boot. As Dan said that storm to the south (now in Plains/Denver City) is moving into a more strongly capped environment. Not ready to give up though - if that storm went up to the south, where the dryline is similarly diffuse, why couldn’t one initiate here in the PVW area, from where it can move into a much better environment than the storm to the south?

EDIT: Actually, upon closer look, both the Plains storm and any storm that goes up on the dryline north of there (west of LBB/PVW) will probably move into an equally hostile environment - 700mb temps 12C per SPC mesoanalysis. Will be interesting to see how the Plains storm fares as it tracks NE into that environment, that will tell a lot about what to expect IF storms can initiate west of LBB/PVW.

 

[Dan Robinson]

Feel like the Lubbock-Brownfield cells have the best potential. They could have 2-4 hours of unimpeded intensification before they run into the stronger capping. SRH is marginal there now but should slowly improve with time. The storm NW of LBB is a player, but the front looks like it is about an hour from reaching it.

 

[Bob Schafer]

I wrote this day off when, yesterday, I saw convection forecast for 15Z. Plus, I don't like to see drylines oriented SSW to NNE, or either an upper level speed max or exit region over my target (the DL). I also want to see sfc winds backing at the (a) TP. Well, I missed a big tornado S/E of Perryton. Win some, lose some. BTW: How cold is it behind this system? For the second time this month Lamar CO set a new record for low max temp. The high today was 54°F, breaking the old record of 55 for this date.