Brandon Sullivan
EF5
Matt.. I was referring to the 29th, on thursday.. Yup.. Sorry bout the mixup..
Anyways, I like the new 12z WRF
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3-28-07 FCST: SD / NE / KS / OK / TX
- Thread starter Brandon Sullivan
- Start date
Matt.. I was referring to the 29th, on thursday.. Yup.. Sorry bout the mixup..
Anyways, I like the new 12z WRF
Mikey Gribble
EF5
Going off what the NAM is showing, I would have a tough time making a call between north central Kansas along the dryline and the surface low near the KS-NE border. I am a little nervous about the moisture. If we get low 60's, I think we are in good shape and I am pretty confident that low 60's will verify after looking at the surface chart and this mornings soundings along the Gulf.
I am not sure what to think about the tornado potential. The directional shear sucks, but I still think a few tornadoes across Kansas and southern Nebraska is a good bet. I am 90% sure I'll be chasing.
I am not sure what to think about the tornado potential. The directional shear sucks, but I still think a few tornadoes across Kansas and southern Nebraska is a good bet. I am 90% sure I'll be chasing.
matt patterson
EF2
If i were basing where i would be chasing off of todays models then i would probably head to W OK along the dryline where directional shear is better, quality of moisture will be higher (pending DL mixing doesnt kill it), along with somewhat of a cap to provide some suppression for isolated storms... Only time will tell...
Ray Walker
This system has some good things working for us along with a few bad ones. I havent really dug deep into the models the past few days thanks to other obligations, however just glancing over the GFS and a few others I have my own opinion to add the this forcast thread. Although I do think that Northern Kansas, and parts of Nebraska look ok I see alot wrong with it also. The further north you go the lower the moisture content, the worse the directional shear gets, and the lower the instability. Also the forcing will be stronger to generat a huge cluster or mess of convection. Now along the Dryline in Western Oklahoma I see a stronger cap, more instability, better directional shear, and deeper moisture. So Matt I really agree with you that western Oklahoma will be the best bet on Wednesday. I still think that this event will produce the first tornadoes of the season here in Oklahoma. Although this system could have better wind feild orientations I still think the speed and directional shear will be plenty good enough for a few tornadoes across the southern plains.
Chris Wilburn
EF4
I agree with Ray and Matt on this one. I too noticed that the further north you go the less instability, moisture, and ability for storms to stay more discrete. Also like the better directional shear, esp. the 500mb winds the further south you go to say western Oklahoma. Not to say northcentral Kansas and Nebraska is no good, but I just like the ingredients better south along the dryline. Will have to see what cap strength looks to be. The models have differences now, but if the current run of the GFS is the correct one it looks to be a really good day. Still a couple days out, but I am looking towards the western Oklahoma region at this time. This can and very well may change.
Chris
Chris
Mikey Gribble
EF5
The GFS shows both Oklahoma and Kansas having dewpoints in the 60's and the NAM actually shows a tighter moisture gradient up North than in Oklahoma.
http://wxcaster2.com/CENTRAL_ETA_SFC_SLPTMPDPTWINDSLI_60HR.gif
As far as directional shear goes, you may get a little more of a westerly component to the 500mb winds in OK, but in northern Kansas and southern Nebraska you get backing low level winds. If I'm looking for tornadoes, I'll take the target with better low level shear over mid level shear.
I do agree that you have a better chance at more discrete storms in Oklahoma since the cap is stronger, there is less forcing and the shear vector is more normal to the boundary, but I'm not convinced right now that convective mode is going to be the deciding factor in this set up, so I am sticking with the Kansas-Nebraska target for now.
http://wxcaster2.com/CENTRAL_ETA_SFC_SLPTMPDPTWINDSLI_60HR.gif
As far as directional shear goes, you may get a little more of a westerly component to the 500mb winds in OK, but in northern Kansas and southern Nebraska you get backing low level winds. If I'm looking for tornadoes, I'll take the target with better low level shear over mid level shear.
I do agree that you have a better chance at more discrete storms in Oklahoma since the cap is stronger, there is less forcing and the shear vector is more normal to the boundary, but I'm not convinced right now that convective mode is going to be the deciding factor in this set up, so I am sticking with the Kansas-Nebraska target for now.
Michael O'Keeffe
I'm favoring the Eta more then the GFS at this point. As of right now I would target NC Kansas into SC NE maybe into SE NE. I like playing the surface low or the dryline. CAPE to 2500j/kg over much of this area and decent moisture though we could use a bit more. I'm thinking the NAM is a bit modest with moisture, because I just glanced at the surface obs and we have 60-65F tds all over E KS. We should have S winds tomorrow and Wed, so just maybe we can get a bit better moisture then forecast and maybe we can get some tornadic supercells with the possibility of strong tornadoes. Even not we will still have suffient parameters for a least a few nice tornadoes. I am planning on chasing this setup if this varifies.
Marcus Opitz
EF2
- Joined
- Mar 24, 2005
- Messages
- 197
I like the way the ETA shows helicity values, CAPE, and upperlevel divergence on the 60 hour run and hence favor the north Kansas, southern Nebraska area. I prefer to chase near the Low pressure area on days like this where from what I can see the winds look to be more unidirectional. I will make my final decision on wether or not to drive from Louisville, KY and meet up with a crew in KC.
Adam Atkins
EF2
UGHHHH WOW the new WRF is pretty amazing. I know it's a model but I like to chat lol. Kinematics and height fields just got a lot stronger. It appears strong height falls will lead to significantly backed low level flow. Helicity will be >400 m2/s2 from KS/NE border north. If the cap is strong enough discrete supercells are appearing more and more likely. Strong tornadoes as well if sufficient instability develops. I'm starting to favor targets from about Hutchison, KS and north into Nebraska because of the incredible low-level shear. With 60's Tds, could be a good show, UNLESS storms fire all at once and congeal into a strong line...which is also likely because of a nearly uncapped boundary layer and a shear vector directing storms very close to parallel to the dryline. Need a right mover in this situation!
Mike Hollingshead
I think I'll just head to the Broken Bow area now.
BBW Fcst Souding
I agree with the possibility of linear "fun"...regardless, it'll be nice to chase a day without the scouring veered low level going ons.
http://www.wxcaster2.com/CENTRAL_ETA_ATMOS_STORM-MOTION_48HR.gif
I'm sure that'll prove fun. Best option might be to be around a good east or se road to just catch things as they FLY north.
BBW Fcst Souding
I agree with the possibility of linear "fun"...regardless, it'll be nice to chase a day without the scouring veered low level going ons.
http://www.wxcaster2.com/CENTRAL_ETA_ATMOS_STORM-MOTION_48HR.gif
I'm sure that'll prove fun. Best option might be to be around a good east or se road to just catch things as they FLY north.
Dal Archer
I think that the best opportunity for tornadoes will be into northern Kansas and southern Nebraska. The forecasted directional shear should be quite nice in this region and I think that storms may stay discrete long enough to put out some interesting action. However, being the Okie that I am I like the models well enough to plan on taking off on Wednesday to shoot for the western OK setup (with an option to move into western KS).
The NAM is forecasting enough of a directional shear component to get me excited for the Western OK/SW KS region. CAPE should certainly be adequate and the forcing should (hopefully) be sufficient to bust the cap this time and get things going in our neck of the woods.
The NAM is forecasting enough of a directional shear component to get me excited for the Western OK/SW KS region. CAPE should certainly be adequate and the forcing should (hopefully) be sufficient to bust the cap this time and get things going in our neck of the woods.
Mike Hollingshead
Actually if it were to happen just like the NAM shows maybe being closer to southern NE would be a better option as the warm sector probably won't be very wide to the north and storms may want to out run that. Then again I don't care for being south of any dl bulge. Then again maybe that will help this day. Erroring to the north is obviously a good choice with those storm motions. Guessing I'll wind up on I-80 ahead of the front and just use the interstate to go east. Lexington it is.
21z LXN
It'd be nice if that cape could be close to that.
Hope the gfs can move it a bit more east than it has it on the 0z run.
21z LXN
It'd be nice if that cape could be close to that.
Hope the gfs can move it a bit more east than it has it on the 0z run.
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Gabe Garfield
EF5
I wouldn't be so quick to down the prospects of a big tornado event on Wednesday. Granted, this setup is not completely free of "flies in the ointment," but it does have major-league potential.
This situation is slightly reminscent of the March 13, 1990 tornado outbreak. Consider the following 500 mb map and surface analysis:
500 mb Map:
http://bangladeshtornadoes.org/UScases/031390/03149000zh5.gif
Surface Map:
http://bangladeshtornadoes.org/UScases/031390/03139021zsf.gif
Storm Reports:
http://bangladeshtornadoes.org/UScases/031390/031390pth.gif
Notice that 500 mb flow was not particularly veered, especially in Nebraska where a number of strong/violent tornadoes occurred. Compare this with the forecast pattern at 500 mb on Wednesday, and you will note that they are not all that dissimilar.
I'm not saying Wednesday will be a repeat of that event, but there is a lot more that goes into a big event than simply considering CAPE and helicity.
Gabe
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Brandon Lawson
EF2
Gotta give oklahoma some love 
Hey Gabe, I'd buy that outbreak for a dollar!! A lot of people are targeting north central Kansas into Nebraska, but I also see a lot of potential in southwest oklahoma.
The WRF has significant cape values of up to 3500 by 18z and dewpoints in the mid to upper 60's before mixing out later in the day. However, I'm really interested in seeing how much they'll actually mix out, assuming they get that high to begin with. This board had a pretty good discussion before the chase season began on the effects that evapotranspiration has on dewpoints, and now we may get to see if they contribute to the forecasted dewpoints on wednesday. Much of western Oklahoma, and even the Texas Panhandle, have had quite a bit of precip recently. I wonder if this will enhance or at least sustain favorable dewpoints in that region.
If we can get surface winds to back even more or the upper-level winds to veer a tad more than they already do, I'd say Wednesday could go "gangbuster" for southwest oklahoma.
And it'd be about freaking time
Hey Gabe, I'd buy that outbreak for a dollar!! A lot of people are targeting north central Kansas into Nebraska, but I also see a lot of potential in southwest oklahoma.
The WRF has significant cape values of up to 3500 by 18z and dewpoints in the mid to upper 60's before mixing out later in the day. However, I'm really interested in seeing how much they'll actually mix out, assuming they get that high to begin with. This board had a pretty good discussion before the chase season began on the effects that evapotranspiration has on dewpoints, and now we may get to see if they contribute to the forecasted dewpoints on wednesday. Much of western Oklahoma, and even the Texas Panhandle, have had quite a bit of precip recently. I wonder if this will enhance or at least sustain favorable dewpoints in that region.
If we can get surface winds to back even more or the upper-level winds to veer a tad more than they already do, I'd say Wednesday could go "gangbuster" for southwest oklahoma.
And it'd be about freaking time
Gabe Garfield
EF5
I'm pretty sure that this is simply convective feedback, since the moisture depth and magnitude should be high enough that mixing will have only a limited effect on the sfc dewpoints. We've had several days of return flow, and from the looks of recent soundings, a tropical airmass is already in place across the Plains. Rest easy...
Gabe
