C-Nimbus wrote:1) What does CAPE and LI stand for (although i think LI is lifting index) and what do they mean
CAPE is Convective Available Potential Energy and LI is (as you say) Lifted Index. They are indices, calculated from values of temperature and humidity at different levels in the atmosphere. If they are calculated from soundings (balloon ascents) then they represent real life, but the indices can also be calculated from model data as predictions for the future. I'm sure if you google CAPE and LI you will find the technical definitions. They both represent different ways of defining stability and instability in the lower atmosphere, and therefore are useful for predicting convection and storm development. Total Totals is another such index.
C-Nimbus wrote:2) What does 8/8 stratocu mean? Obviously i know what the cloud is, but its the 8/8 thing that gets me
Steven has already answered this - the sky is divided into eighths or oktas for the purposes of cloud observations, so 8/8ths is totally cloudy. StratoCu is Stratocumulus, one of the ten basic cloud forms. Again, a google on Cloud Types should yeild some photos and definitions of these.
C-Nimbus wrote:3)500mb temps, what does this really mean and its effects on T/S developement. Am i right in thinking that this indicates upper level instability due to a cold upper?
Again, Steven has answered well. 500mb is halfway up through the atmosphere (by weight) - ie the surface pressure is 1000mb, so 500mb is half the surface pressure. Its usually around 18,000ft altitude. The colder it is at 500mb the stronger the lapse rate is for any given surface temperature (ie the line on a Tphigram is steeper). This usually (but not always) makes the atmosphere more unstable. A google on atmospheric stability should yield further info.
C-Nimbus wrote:4) What does Vvel mean? (from TonyT i think...who surely is a pilot!)
Nah, I've only ever had the controls of a plane once, and damn near made myself sick in the process! I laughingly call myself a professional weather forecaster, in the sense that some people actually pay me to tell them what the weather might do.
Vvel is vertical velocity, ie the vertical speed of air movement. Its usually quite slow (compared with the horizontal velocity, ie the wind) so its often quoted in centimetres per second. A map of vertical velocity will show you where there are broad regions of ascending air (often in depressions and troughs, also upwind of mountains eg west of the Southern Alps in a nor'wester) and descending air (often in anticyclones, ridges, and in the lee of mountain ranges). This is an important parameter, because ascending air supports the development of clouds and rain, while descending air tends to suppress cloud and rain development.
C-Nimbus wrote:5) on shore breezes, which seem to be a cause of some T/S developments, what is the development mechanism for these, is it simply a temp difference between the land and the sea in an afternoon situation?, if so, do we get onshore breezes almost every day?
In theory yes, its just about temperature differential, warm air over land rises, cool air from the sea rushes in to take its place, hey presto a sea breeze. In practice its a bit more complicated than that - eg Auckland has two sea breezes, one from each side, and one may be more or less dominant depending on the synoptic scale weather situation. And in Canterbury we often get a NE "sea breeze" even if the land is cooler than than the sea - because in fact our "sea breeze" is a lee trough wind, whereby the upper trough formed by the prevailing westerly flow over the Southern Alps sucks a low level (ie less than 3000ft) NE breeze inland.
C-Nimbus wrote:6) can you tell what sort of lighting (eg CC, CG, GC) it is by the sound?
Fascinating question - no idea, sorry.
C-Nimbus wrote:Can I also suggest to Steven Graham that we have a technical forum for all of the airheads like me?
Personally i would be against this idea - lets keep all the discussion together in the one place. Its not like we have so many threads that its hard to read this forum (unlike some).
