Subj : Re: Thunderstorms Was: Wegman To : Daryl Stout From : Nancy Backus Date : Mon Aug 05 2019 15:50:34 -=> Quoting Daryl Stout to NANCY BACKUS on 31-Jul-2019 15:55 <=- NB>>> More often, we just get snow.... just like we often just get rain NB>>> (even very heavy rain) without any thunder/lightning.... :) BM>> True. Maybe when Daryl gets back he'll explain it to us. NB>> I don't think I've seen him jump in on this yet... DS> Maybe we should look for Jim Cantore. DS> Seriously, if you have enough lift and instability, along with DS> charged particles in the cloud, you're going to get lightning and DS> thunder. The type of precipitation is determined by the air DS> temperatures aloft, at the mid levels, and at the ground level. Well... When you do jump in, you do with a vengeance...! Seriously, it is quite the treatise... although I snipped out quite a lot for the reply, I saved the whole thing to its own file to refer to in times to come.... :) DS> I forget which one is better for making snow cream and a snowman DS> with (never mind Calvin and Hobbes with his anatomically correct DS> creations ). The dry powdery snow is best for skiing, but in the DS> mountain areas, a large amount of such could lead to deadly avalanches. For snowballs and snowmen, one wants a snow with some moisture, so that it packs nicely, but not so wet that it turns to ice when one compacts it.... DS> What you mentioned is known as "VIRGA"...where the precipitation DS> evaporates before reaching the ground. You can still get the lightning DS> and thunder, but there is dry air at the low levels, and at the base DS> of the storm, that the precipitation dissipates on the way down. Once DS> the lower levels moisten up, then precipitation reaches the ground. DS> Doppler Radar may indicate it's raining, but surface observations note DS> that it's not. Actually, what I was talking about wasn't the lack of precipitation, but the lack of thunder and lightning.... Many times there's just rain, even heavy rain, and none of the electric stuff.... And only rarely does one get thunder and lightning with snow.... I have on rare occasion, though, also experienced the virga... DS> Now, the first stage of a storm is known as the cumulus stage. DS> Moisture rises and condenses into clouds...basically, the entire storm DS> is composed of updrafts. Inside the cloud, particles of dust, dirt, DS> etc., known as condensation nuclei, attract the water droplets, which DS> bump into each other, and grow larger. This is known as coalesence. DS> Over time, the weight of the water droplets in the cloud become too DS> heavy to be supported and held aloft by the updrafts, so they fall, DS> creating a downdraft. That essentially is how I understood rain (and snow) storms to form... Barry was talking about an experiment with oil that he thought could be analogous... but that did require some difference in potential as well as just the coalesence.... ttyl neb .... Seen it all, done it all, can't remember most of it. --- EzyBlueWave V3.00 01FB001F * Origin: Tiny's BBS - http://www.tinysbbs.com (454:1/452) .