3/30/06 FCST: IA/NE southward to central TX/LA

[Rich Thompson]

Looking at morning satellite imagery and surface obs, I'll agree with shifting the initiation area to W of I-35 in OK and near I-135 in KS by early afternoon. Wind profiles most favorable for discrete storms tend to favor central and northern OK this afternoon, storm motion won't be quite as fast as areas in KS, and a slower moving dryline may allow for storm initiation opportunities near I-35.

With mid 60 dewpoints, today would likely end up being a fairly serious tornado outbreak. We'll likely be dealing with low 60s and temperatures in the 70s, which is fine but not quite as strong as you might want to see given the strength of the deep layer vertical shear.

Roger and I will likely head N of OKC by 11 am (must pick up son from school first!).

Rich T.

p.s. As mentioned last night, such a mobile/open wave does not appear to fit the "cold core" conceptual model. Today looks more like a typical warm sector chase to me.

 

[Todd Rasmuson]

New Day 1 Outlook out this morning appears SPC Is sticking with the area of ne ok
and ern and sern ks into extreem wrn mo for best tornado threat but did shift the
mod risk a bit further w including a little bit more of central ok runs now from medford,ok
to okc to sulphur to atoka,ok line east and north of that line is the mod risk area.. for oklahoma
still at this early hr i have a few questions, one being cloud cover this morning, how much if any
will erode through out the morning hours? and am closely watching radar to see what the convection
that has tryed to go up just w of the okc metro area does, for the most part has just been light showers.
but i would have to agree attm with spc on ne ok/se ks although i still have some fairly good hope
for central, ern ok, parts of sc ok but the next few hrs will tell the story of the day, how this will progress...
iam thinking we may have a heating problem with temps becouse when i got up from a short nap this
morning after sunrise here at my location n of adm noticed cloud deck is quite thick, so that could be a
concern... just have to wait and see as the morning goes along... more updates later

EDIT: one note to the spc outlook in my opinion i wouldnt be surprized at the 1630 outlook to
see the mod risk pushed even further west depending on what happens by that time, becouse
quite honestly i just dont see that dryline moving that rapidly to the e today, i think it will setup
between 44 & 35 maybe along the area of west of highway 81.. but i dont see it going as far as
e of 35 by just afternoon, but we shall see what happens... also a note to the above mentioned
showers that tryed going up over central ok, at last look on the radar appeared to be on the downward
trind at last look...
Todd Rasmuson

 

[bbarjenbruch]

I agree, this is opening up into a warm sector chase that just happens to have some great mid level lapse rates. Convection is ongoing in Lincoln right now, putting some discrete outflow boundaries down. Regardless of outflow, my new target is Norhtern Kansas along Highway 81... chasing the storms back toward Lincoln with time. This is really looking like a great setup. It seems that God is paying us back early this year for what we missed out on throughout last year

 

[Edward Ballou]

Looks like the triple point is in SC NE with storms already firing there - namely one larger one that is currently SVR warned. We have a pocket of larger CAPE here and then increasing as we go south along the front. Dps are much better in the OK region that's also close to this dryline bulge I'm seeing over Kansas. As someone mentioned earlier, the cloud deck could hamper things unless some clear slots develop.

I think this is really a locational one - if you're north of all this, you'll probably try for the NE stuff. Some might choose the middle KS bulge area. And finally, let the southern people go for the OK stuff. So there - 3 possible areas of development that I believe are worth taking a crack at. As to which one I favor the most, that bulge really interests me. As I will be virtually chasing today, I'll put my target on the Target page. I'll be interested to see how all this pans out.

Good luck all, and be safe out there. Don't let the moisture in the air this morning get to your head.

 

[Chris C Sanner]

CU is already developing along the dryline and in many other areas across the target region. I've got one more class then its time for some chasing. RUC veers winds somewhat across target area, but NAM keeps them backed in C/NE ok. Going to be a busy day for those warning coordinators I feel....

 

[Bill Schintler]

Target:
30 miles east of Sioux City, IA.

Timing:
3 PM CST.

Comments:
This target is probably further north then what most chasers would choose, however the possibility of low-topped supercells just to the northeast of the surface low in interesting. Ongoing convection this morning will diminish and move northeast of the target area by noon. Renewed convection will initiate by mid-afternoon. Hail to golf ball size will be the primary severe threat, while a few weaker tornadoes will be possible.

Discussion:
A broad area of SFC low-pressure will develop under the left-exit region of a 70kt 500mb jet max. Soundings will exhibit steep lapse rates in the 800mb to 550mb layer, along with an inversion or “equilibrium levelâ€￾ of only 500mb or about 18000ft. A 100mb-deep moist layer has pushed north beneath the shallow EML which will support low-topped convection. In an environment void of forcing, surface-based parcels would need to reach the upper-70’s to reach the LFC and make use of 500J/kg of MLCAPE. Given the widespread cloud cover, this clearly will not occur, however very strong forcing will spread into the area with the advance of the vort max and will allow parcels to become near surface-based. Shear parameters will generally be “averageâ€￾ at best, however good turning of hodographs below 1km should be present as a 45kt 925mb jet noses in east of the MO river, juxtaposed on top of SERLY SFC winds of 10kts. Given low WBZ heights lowering to 8000ft with the advance of the upper-level system, hail will be a significant threat.

- bill