Water Vapor imagery, what does it tell me?

[tom hanlon]

So I take a look at the GOES East Water Vapor loop and I see some swirling waves and clouds. Very pretty. How does this apply to my nowcast of a situation.

http://www.ssec.wisc.edu/data/east/animati...goeseastwv.html

What does it tell me that can aid in a NOWCAST of a weather situation ?

Does it show me advection at the surface ? If so than I can use it to see if dewpoints will be high enough and the LCL will be low enough and the air will be wet enough for convection to be powerful.

I doubt it is showing surface conditions though it just don't look like that.

Looks more like I am looking at the conditions at the 500MB level or so. Is that correct ? If so it sure seems easier to read than a chart with windbarbs and the like. Are the swirling clouds more or less reflective of what is going on at the 500mb level ? Can I use this to get an up to the minute view of the upper level jets, troughs and ridges ?

I dunno I have taken a met class and looked at all the charts and applied them to the weather but it was more synoptic in scale and more chart and model focused rather than live data and nowcasting so I am trying to figure out how to firmly place live data from the web into the picture of what is happening on any given day.

Please post info on how you use the Satellite WV imagery to plan a chase.

Thanks

Tom Hanlon

 

[Jason McKittrick]

The water vapor imagry is also known as moisture channel. It does not show "clouds". It also does not give you any information reguarding surface processes.
The water vapor product is an image of a specific wavelength of radiation, I believe it is 8 microns. That wave length, is the wave length emitted by water vapor at approximately 400 mb.
This product is useful for nowcasting because since it shows you the location of upper level features, such as short wave troughs and jet streams. Dark areas not only represent dry air but also imply downward vertical motion. Bright white areas many times are areas of cloudiness but more importantly they coincide with upward vertical motion. This product allows you to view the location, past movment, and a qualitative assessment of the strength of upper level troughs that may not yet be associated with any significant cloud features.

 

[tom hanlon]

Thank you for the informative reply.