SuperCooled Water Droplets

[your_dreamguy]

Yo dudes

Does anyone have a better description of super-cooled water droplets than the limited info. the FAA gives out. All they say is that Supercooled water droplets indicate freezing rain above and that they freeze on impact.

What about other info.??? Are these droplets formed in TSTRMS??? etc.

Also, does anyone know a good website for weather info. and simple explanations (for topics like fog, hail, etc). I heard USA Today's website used to have something but I couldn't find anything.

 

[avbug]

Supercooled droplets exist down to minus 40 degrees. They occur when liquid precipitation falls through or into a cold air mass. The droplets are prevented from freezing by surface tension. If this tension is broken by striking the surface of an airplane, the droplets freeze. Thunderstorms are one source of potential supercooled droplets, but any form of precipitation that causes supended moisture to rise or to precipitate out while still liquid, may be a source.

Freezing rain is an indication of warmer temperatures above, but supercooled droplets do not necessarily indicate warmer temperatures above, nor freezing rain above. Merely the presence of droplets of water that are cooled below the freezing point of water.

 

[414Flyer]

Anyone who has done much with cloud seeding (if they are top seeding) will be able to talk a lot about it.

Yes as Avbug said, water droplets can potentially stay in liquid for to minus -40, although that is not entirely common.

Ice melts at 0C, but liquid water does not neccessarily freeze at 0C. There are some aspects regarding physical factors that can keep water from freezing. When cloud seeding, we look for liquid water, existing from -5 to -10 C for the appropriate altitude to work. When you get icing on an aircraft, you are finding liquid water drops that are freezing to the aircraft on contact.

When you look at a thunderhead and see lots of "texture" and "crispness" to its shape, that is liquid water you are seeing, and it is still in its growing stage. once it loses that and looks wispy, its all turned mostly to icy crystals and is going to be dissipating most likely. Liquid water containts a lot more energy (heat) than ice crystals, even if both are at -5c

 

[mar]

John Muir is a personal hero of mine.

I like that quote a lot.

One last thing: Only de-ionized water may be supercooled.

You know, pure like rain water. No minerals. Tap water contains minerals (good for nutrition) so you can't supercool it, the ice crystals would form on the minerals.

 

[avbug]

Sounds like a job for Sharper Image.

 

[cj610]

MU-2 SCWD Video

Back when I use to fly the MU-2, we had to watch a video about the plane and SCWD. It discussed the different sizes of the droplets and temperatures. Basicly it was suppose to scare us out of letting the MU ice up. The video was made in conjuction w/ the FAA. I suppose if you contacted your local friendly FISDO they might be able to tell you how to abtain it.

CJ610