4/10/05 FCST: Southern/Central Plains

[Dan Dawson]

One thing that jumped out at me as I was looking at data tonight was the fact that the 0Z upstream soundings in the warm sector have a significantly deepr moist layer than what was advertised on the 12Z soundings. OUN AFD mentions this as well. Also, I really like the new 0Z Eta in that it holds the dryline a little further back from previous runs: still west of I-35 by 0Z. I really don't want to chase storms all the way into the woods of eastern OK again, so I like this development. Also, the directional shear, while not ideal, is still there, with about 30-60 degrees of turning from the surface to 500 mb most areas ahead of the dryline. Taking a closer look at the orientation of the dryline by 0Z, as the Eta advertises it, from central OK NW to the surface low in SW KS, the orientation is nearly SE to NW, unlike last Tuesday, where the dryline had a much more S to N orientation. Just eyeballing the sfc to 500 mb shear vector, this actually isn't a bad orientation, with the shear vector just ahead of the dryline being approximately S to N, or even a bit SSW to NNE. Thus, I'm a little more optimistic about longer-lasting discrete cells in central to northern OK, now that I've had a chance to examine the 0Z runs and data a bit more closely.

 

[Dan Dawson]

Sorry Jeff, I see you and I mentioned very similar things, I was composing mine and posted it before I saw yours

 

[Shane Adams]

Well I'm not thrilled at the latest run of the ETA. For some reason it wants to plant a huge area of subsidence along the dryline by 0Z, effectively killing any shot of initiation along and just west of I-35. I don't understand what's happening here, but it looks as if it has something to do with the huge spiral of UVVs spiked from NW OK into WC KS, wrapping around the low. I suppose this is creating some kind of sinking wave effect, which is what the model is picking up on.

Speed shear could be decent, despite largely-unidirectional flow tomorrow across much of the risk area. I'm most intersted in watching surface data tomorrow morning, to see if we can get some good backed surface flow. The thing that really killed the southern half of the risk area last Tuesday was a severe lack of backed surface winds. Even with the marginal speed shear in place, enhanced backed flow at the surface could give us a shot at an isolated sup or even tornado. I don't think playing the best helicity areas along the dryline is any more of a longshot than driving to that LOW and hoping you're there for the 10-15 minutes those storms are producing landspouts.

 

[Jim Bishop]

I believe the best tornado threat to be near the surface low in southwest Kansas. Alas, the drive from Houston will be too long, along with having to be back in time for work Monday morning.

Therefore, I'm going to play the dryline convection near Waco, Texas where the storm motion looks to be northeast. I think this will allow for storms to be discrete initially, but *not* for long, as the 850winds will be rather veered. Tornado potential in this area looks terrible based on low level helicity values and forecast hodographs.

Good luck to all that go chasing!

 

[George Flickinger]

If I were chasing Sunday, around Medicine Lodge, KS would be my starting point...GF

My forecast is below, and I will sit this one out...GF
www.flickingerweather.com

 

[Jay McCoy]

I dont like all the convection going on in Kansas and North oklahoma. I dont think there will enough recovery for good CAPE's. I also dont want to get too far from the low itself so I and Kanani plan on splitting the difference for now and will set up on I-40 near Clinton (or where ever the dryline is). That way we can play the dryline early but if anything good starts north or south we can move on it. Sortof the difference between 2 evils. Should get some storms no matter what but a tornado would be an extremely lucky catch today

The dryline is still in the east Tx panhandle with nice clearing ahead of it. There should be a nice little bulge right along I-40 where CAPE and LI's are already climbing. SRH is only 150 but that will do for now.

Hope to see some folks in our area today.

 

[Bill Schintler]

Chase target for today, April 10

Chase Target:
Pratt, KS

Timing:
Storm initiation 2 PM CDT.

Storm type:
A few F0/F1 tornadoes and hail to 1” diameter.

Discussion:
A vigorous upper-level system is lifting into the southern plains. At the surface, a dryline will push into SWRN KS and NWRN OK by early afternoon as surface low pressure tracks slowly towards DDC by 00Z. This feature will serve as the focus for renewed storm development. Instability will be marginal for severe storms – afternoon high temperatures of 73/60 should yield MLCAPE’s of 500 to 1000. However, 0-6 km shear should assist in storm organization. Storm motion will be to the NNE at 25 kts.

- bill

 

[Philip Flory]

Current target for this afternoon is Larned, KS. Looking at 12z NAM and latest RUC, it appears RUC is underdoing moisture a bit, NAM solution of 60 td line into S KS by 0z looks plausable. I am not overly concerned over current convection over S KS/extreme N OK... convective trends indicate this convection should be exiting the area within 2 hrs and no development is currently taking place over N OK. Values of 1000-1500 J/KG SBCAPE seem likely ahead of dryline from SW KS into NW TX. SFC dewpoints should be somewhat more limited NE of the LOW this afternoon .. although 55-58 td's should be fine. RUC has indicated a bullseye of SFC conv just NE of DDC the last few runs, along with increasing conv S along dryline by 21-0z. Plan currently is to play the development near the SFC LOW near DDC.... and possibly shift south along the dryline into SC KS if any isolated convection can fire, I would not be surprised to see an isolated supercell or two in S KS near the Medicine Lodge area with the locally enhanced SRH of 200-250 and locally backed flow.

Departing for the Kinsley/Larned area within the next hour.

Good luck all

 

[Shane Adams]

Socked in with clouds here in OUN currently, and not very excited about the prospects for the DL along the 35 corridor. Forcing will ensure a line no doubt, but our window of discrete sup action seems in jeapordy. With the cool temps and clouds lingering, I'm starting to feel there won't be recovery time for the DL. I mentioned last night about the lack of lift showing on the ETA along the DL, and current RUC runs aren't much better regarding UVVs at 500mb. Also not impressive are the current RUC CAPE forecasts, which struggle to reach 1000j/kg by 21Z per the current 9-hour run (which would be the best window of opportunity for sups).

The only area that seems to stay consistent with each run is the area ENE of DDC. Contemplating this area for later in the afternoon, as I'm not going to through myself NW to the LOW in search of CC tornadoes. Thinking is to play the area ahead of the LOW as it shoves ENE across Kansas.

Getting ready to start satellite and surface analysis to try and determine how long to hold out for DL storms in central/southern OK/north TX. I will most-likely bail north on 35 to KS if conditions havebn't improved here by noon. I just don't get a good feel for these type set-ups, I'm like a fish out of water today (again).

 

[Adam Atkins]

Update

16Z RUC must have picked up on the subsidence filtering into W OK/TX panhandle because the precip doesn't break out until 00-3Z in central OK. The dryline appears to stall and tighten just west of I-35, which makes sense as the low deepens and SE surface flow backs and increases through the day. CAPE maximum appears after sundown via cold air advection at mid levels and it appears the surface based CAPE will be limited east of the dryline by this fun stratocu drizzle. Just east of the dryline has been sunny all day though, so surface based storms could develop early, as in the next three hours. They won't be long lived discreet cells as they motor off to the NNE due to this terrible air in C OK though. I would target Lawton right now and wait for the dryline to buldge.

 

[Nic Wilson]

I like your target Adam, I'm sitting in a Fairfield/Marriot Suites in Lawton right now haha. The cu field is thick but insolation is decent with temps climbing into the low 70's now and should keep rising ahead of the dryline push. Currently 70 over 61 in Lawton. I like the possibility of a quick discrete cell down this way in the next 1-2 hours, but the forcing will quickly turn it linear and I'll ride it on back to Norman. If anything the morning showers helped strengthen the low level moisture in the I-44 corridor. Good luck to everyone trying their luck in Kansas or along the dryline in OK/TX!

 

[Bill Hamilton]

Posting this for Joey.

Originally posted by jketcham
I was just gonna wish everyone out chasing the best of luck. Due to lack of funds, high gas prices I won't be able to make it out for this one.

With the DL finally moving and dew points dropping across the region (FDR 80/32 GAG 72/33) I am still holding hopes for SC/C OK. The cloud cover has broken in these areas and temps are climbing quickly.
Good luck to everyone headed to Kansas as well.

 

[Brett Adair]

Classic dryline setting up....OUN to ICT needs to watch out as good mixing is taking place along this boundary. Check out the differentials across KS/OK. New tornado watch will likely be required for OK soon.

[Broken External Image]:http://weather.cod.edu/wx/public/sfc/kc.wxpsfc.gif

 

[nickgrillo]

Cell has just exploded southwest of Chicasha ahead of the dryline and is headed straight for OKC. Cells are also looking pretty darn good in southcentral Kansas, with Pratt and Stafford county storms showing excellent rotation ... along with some hail potential as well. Stafford is now TOR warned...

..Nick..

 

[Scott Lincoln]

Right now the primary weather concern would be the mini-supercell that just passed to the west of Russel, KS. Last report from the NWS has a large tornado on the ground. The storms in Kansas have been the ones producing the confirmed tornadoes. This still appears to be the area with the highest potential for further tornadoes in line with the types of watches issued by the SPC.