crimsone

Just to give some kind of idea of the human feeling involved with such an eruption - when was the pompeiian eruption, and where on the scale was it? I'm tempted to thing it was the AD79 one, but somethings telling me it may have been earlier than that.

Maybe - but lithium ones would last longer.

What!? A discussion of teleportation, quantum physics, string theory, relativity and lightspeed, and yet no mention of the Zero Point Field? I thought this was supposed to be the Unified Theory of Everything!?

E=MCC is the problem with lightspeed. It demands that a subject must reduce in mass as it approaches the speed of light (matter -> energy conversion). As for this teleportation thing and the speed of light though, Isn't there some wierd magical quatumn thing that says that when you chang the polarity of a particle on one side of a room/the world/universe, it's matching particle on the other side of said explanse will also change (instantaneously)?

rain here is torrential! My patio doors look like a cross-section of a small waterfall.

hankyou very much Hemlock and John - your help is very much appreciated

Ah. sorry. That's just my mind going screwy and coming out with words in the wrong order. lol. I shall PM tlater though - thanks

After searching for definitions, it seems that I can only find half a story from the AMS glossary. We always hear how something is an "upper level low" or a "mid level trough", but it seems that a description is evasive. So far I've managed to find out that the upperlevel is usually considered to be anything above 850 hPa, that the low level is up to about 6000 feet, and the mid level is everything inbetween. The thing is, these are approximates. How exactly are these levels defined? What values are they defined as? Are there any characteristics specific to each level? I mean, I know the earths atmospheric flow is a general trend from west to east, but is this true of all three levels? What's the difference (for example) between a mid level and low level trough? Is there anybody that can offer a definitive description of these levels, or is it something that's just approximated as we go along?

Cool. Thanks John - I thought I was going crazy there for a minute. lol

Oh, I don't know. We may get one more major out of the season yet. I must confess though - 4 TSs and 5 Hurricanes so far seems a little short of par?

I've recently been doing a lot of work on Wikipedia article (Extratropical cyclones - as in normal run-of-the-mill mid lattitude ones as it happens). I figured that reading and editing wikipedias meteorology and climate articles might be a good (though by no means perfect) way of learning a bit more. I had pretty much thought with certainty that forecasting the weather for a maritime area/country would be a little more difficult than doing so for a landlocked nation. I was under the impression that forecasting for a more landlocked area could be done a little further out with a little more certainty. I was actually so sure that I added a short sentenece or two to the article saying as much. When somebodyy (quite rightly) suggested that the statement needed a citation though, I looked for one and could find nothing (looks like I shall be removing the statement then! lol). The question is then, was my original view of maritime vs landlocked forecasting correct, or was I grossly mistaken? (and if I was - where the heck did I get th idea from in the first place! lol)

Frequent lightning - unknown type because each time it strikes it blinds me. (wow). Heavy rolling thunder, and somewhat breezy - moderate rain only so far though.

The vertical shear from that ULL is enough to displace the center. Never the less, this should be called as a tropical storm later today. The center is passing a buoy in a few hours apparently, which will give a fair idea of where it's at. Models are in unusually tight agreement on the track. recurving as Gordon and helene did.

TD 9 has just been officially announced in the Atlantic. From the uncertainty the NHC have expressed over the initial heading, it seems that the track is a little uncertain due to a recent reformation of the low center. Never the less, given reasonable light vertical shear and warm(ish) seas, gradual intesification is being forcast, making it a 30 kt tropical storm in 12 hours ( TS Isaac). Forecast track follows the (now standard) recurve taken by both Gordon and helen, and it seems its expected at this early stage to happen quite quickly. I note though hat they only mention a concensus on this from three models - one being the NOGAPS model which has been pretty good of late year in all fairness. Currently located at 26.5°N 53.1°W between a low to mid level ridge and upper level low heading NW at 12 Mph with a pressure of 1012mb. Penny for your thoughts, anyone?

DO we have our next system here - just creeping onto this sattelite image?

NHC seems to have issued its final advisory on Helene, concluding as they do that extratropical transition is now complete.

Heavy rain, gusty breeze in kenfig hill. Numerous thunder in kenfig hill an hour or so ago. Numerous IC and CG on the hills between North and West of here just a few miles away, now moved off further into the distance. Hope it's not the end for today :huh:

No problem Happy to help.

In reply to your first question, yes, it does As for the second question - that's something that none of us can answer with any certainty. The track forecast is just like any other forecast in that the further away you try to forecast, the harder it is and the greater the margin of error. This is what is shown by the "cone of probability". While the line represents the best idea of where the cyclone will go, the shaded cone around it indicates a margin for error. The trouble is, while intensity forecasts for the cyclones themselves can (in theory) be predicted with far more certainty than we could the weather in the UK (baroclynic synoptics) at a longer period, The uncertainty of the forecast for environmental conditions (fronts, highs, lows, etc) means that the further away we forecast, the harder it is to predict what effect theywill have on a tropical system, and thus what effect they will have on it's track and intensity. At 5 days out, there is a significant margin for error. As it stands, the current NHC track brings helene just short of Ireland in a weakened state. (depression rather than storm). It's worth mentioning though that while extra-tropical systems generally bring somewhat less rain than their tropical counterparts (or pervious incarnations), the effects of the winds can be considered to be no different from tropical systems - if a cat 3 hurricane goes through extratropical transition, and the resultant "extratropical storm" re-strengthens and deepens with windspeeds as deep as a cat 2 hurricane, the winds will do just the same damage. As a general rule though, extra-tropical storms arising from hurricanes are far broader than their tropical cousins, and so effect a wider area. Overall, it could turn out to be a damp squib for the UK, or it could turn out to be quite strong. We just can't tell yet. If I've said anything out of place, no doubt one of the others will pick me up

My my that track looks pretty http://en.wikipedia.org/wiki/Image:TD82006atlantic.gif Incidentally, this GFDL run looks interesting. It seems that at the moment, the models are divergingmore on the subject of intensity rather than the track... http://moe.met.fsu.edu/cgi-bin/gfdltc2.cgi...;hour=Animation Incidenentally though, it also appears to recurve Isaac into the mid atlantic, but it does seem to be sending a possible Joyce into the Carribean. ....Then again, it's the GFDL I'm takling about here. lol

To the best of my knowledge, the NHC only issue forecast tracks up to the point where the system becomes fully extratropical.

My question would have to be "who's worrying?". A lot of people on here harbour secret or perhaps unconcious desires to see an ex hurricane make landfall in the UK as a powerful extra-tropical system. Orthers are just interested in where the track will be, using theirselves as the quite natural reference point. the "what if", "where next", and "where now" questions are all part of the fun in following tropical systems.

lol. thought I might be I should add here though that there is a bit of a typo in my post there. I didn't mean to imply that I was wondering if that was the methodology for the whole forecast - just whether it might play a substantial part. Not that it matters, the answer is no. lol Viking - I award you the advanced certificate in BS detection. (unfortunately it's quite large, and so if you could paypal me £10 for postage, or better still, sent cash to... :lol:

My god! It's Satsigs 2 already! lol With regard to the average - would I be mistaken in saying that with this kind of long range forecast, the methodology lies with comparison to the most common setups of previous years related to given signals? This being the case, surely the average would need to move with the times to an extent (like 30 year spans) in order to have a better comparison for likely setups? I would have thought that where information is so limited, such a source of information would be an invaluable piece to the puzzle, and so would need to be kept reasonably recent in order to be valid for the forecast. Or on the other hand, I may be completely looney. lol

I like that ofrecast. From both the page there and the graphs for the UK on the link in the page, it's almost like the met office is saying "Your guess is as good as ours really, but at least we've come to this conclusion scientifically." Absolutely fantastic. lol