1/2/06 Bust: Capping Inversion Question...

BMX has stated that we have a cap....I am not seeing this on the BUFKIT soundings from the latest RUC models. Can anyone show me how to read the cap on the sounding itself instead of this numerical crap?
 
BMX has stated that we have a cap....I am not seeing this on the BUFKIT soundings from the latest RUC models. Can anyone show me how to read the cap on the sounding itself instead of this numerical crap?
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The RUC forecast soundings I just looked at don't show much of a cap (with CINH in the -20 to -30 range) near BMX, which fits well with the SPC Mesonalysis (though that's based on the RUC as well). Another RUC run (w/ TAMDAR data) indicates a moist-adiabatic layer from the sfc to about 800mb... So, as long as the theta-e at the sfc is lower than the theta-e of that layer, you'll have a CINH profile that's pretty deep yet skinny. That said, I'm not sure good these RUC soundings are... The lowest 50-75mb is pretty saturated in the RUC forecast soundings, yet this isn't likely given full sunshine and southwesterly flow at the sfc. If anything, this would yield a cap that would likely be less than the rUC is analyzing (which is not much).

EDIT: For clarification, there doesn't need to be an inversion (temps warm with height) when you have a Tparcel < Tenvironment (CINH layer). For example, if the parcel is saturated, but a layer of the atmosphere has lapse rates weaker than 6C/km, the saturated parcel will cool quicker than the environment... You can end up with a layer with CINH that isn't an actual inversion, which is pretty common.
 
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Well, this profiles shows a little bit of a cap. The RUC data from ANB is also showing that the CINH and cap should have been broken given only a lower level CINH of 36J/kg from about 925-950mb.
 
Brett,

That sounding doesn't show much of a cap for a mixed parcel (which the yellow trace indicates). If you take a surface parcel, you'll see that there is much higher CINH. In this particular case, the storm may not ingest exact surface parcel, but rather parcels a little above the surface layer.
 
Brett - well I thought you were capped fairly strongly, but after reading Jeff's posts above I'm suddenly unsure of myself ... go figure.

Wasn't sure what part of Alabama you are in exactly, so I pulled up Huntsville at http://www.wxcaster.com/rucskewts.php3?STATIONID=72228 and ran the 0z RUC. Go up to the 700mb (10,000ft) level and your temp line is almost the same as your surface temp, looks like ... (almost 20 degrees Celsius, if I'm reading this right) ... that's pretty dang warm for this time of year ... this time of year you'd ideally like to see the cap temp no more than 4-5 degrees.
 
Brett - well I thought you were capped fairly strongly, but after reading Jeff's posts above I'm suddenly unsure of myself ... go figure.

Mike, I just used the BMX sounding valid 20-21z as obtained at http://www-frd.fsl.noaa.gov/mab/soundings/java/ ... The sounding you showed does show significant CINH/capping.

EDIT: I wouldn't put too much stock in model forecast soundings, either. Many oddities may pop up depending on the model used to derive the sounding, including the type of convective parameterization used.
 
I am 20 miles due east of EET in SRN Talladega County. The 15z RUC indicates that only a 2-3C 700mb temp.....I'm still not understanding why convection didn't fire.
 
Well - just looking at it from my amateur perspective, I don't see anything really wrong with that setup. Guess you'll have to chalk it up to another unknown fly in the ointment ... I'm sure there's a good explanation, but then there are plenty of days we think things should happen but never manage to for one reason or another. Sorry Brett!
 
Well - just looking at it from my amateur perspective, I don't see anything really wrong with that setup. Guess you'll have to chalk it up to another unknown fly in the ointment ... I'm sure there's a good explanation, but then there are plenty of days we think things should happen but never manage to for one reason or another. Sorry Brett!

Me either....hell, I'm just glad I didn't go to GA for an MCS. I would rather be sitting with one of my friends that is in KY right now with supercells breaking out ahead of the line.
 
Another Amateur...

I don't know all hope has been lost. The Cold Front is still out their somewhere. VIS Sat images show alot of sun and surface data shows 81deg 59 dew point in central AL.

I have been out in the plains one many ocations everything 100% and NOTHING..
 
I found it....I was reading wrong....the RUC indicates that there has been a level between 860-900mb of CINH of 160-200J/kg. That is pretty stout.
 
Wow - those supes ahead of the line in KY really are getting their act together aren't they ... the one on the KY/TN line in south-central KY looks PARTICULARLY interesting to me. They have included the 'can and sometimes do produce tornadoes' in the svr t-storm watch language there. The entire line has a string of pearls look to it for the time being anyway. Sorry if this is discussion has started to reach the limits of this forum ... Brett's comments just made me take a look at radar for the first time - wow.
 
The big thing I notice on that BMX sounding that Brett posted is the significant dry air aloft - possibly too dry for cloud development. Add to that a slight hint of CIHN, and convection might be supressed.
 
Look at aircraft soundings to get a better idea of the cap, as opposed to a model forecast.

Is there a source for aircraft soundings online? I was getting it via the LDM, but for some reason ACARS kills my LDM...
 
I'm not sure there is anything that is publicly available any more, but during events you can't go with model soundings from 12+ hours before. If you don't, at the least use the RUC analysis sounding, but not a forecast, to help pick up small (but very important) details.

- Rob
 
Aircraft soundings are integrated into RUC forecast.. Use w/Tamdar at Java soundings at FSL website expirementaly into the RUC DEV2. Not avaliable in raw format just RUC soundings and products which use it. I've seen at least one study about the improvement in having more correct moisture profiles during convective events not much else, yet.
 
Yeah, I usually use RUC soundings... Alot of times I have to manually adjust/modify the sounding in the low levels, as it usually has incorrect T/Td's resulting in either unusually high or unusually low CAPE. It's also a hassle because the temperature profile can sometimes be significantly off (for instance - comparing a 00Z RUC sounding to an actual 00Z RAOB). I imagine this would hold true for other hours of the day as well, not just the observation times. I think I'm gonna start pulling in the high-resolution RUC, I'm currently ingesting the 40KM stuff.

Anyway, I'm definitely not gonna chalk this one up as a bust. Within a couple hours of this thread being started, things got pretty active.
 
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