Different levels of circulation, how to tell the difference

[Loring]

A while back i took a look at a swirl, which looked to me based on IR and WV, pretty healthy. turned out to be nothing, and i was told that it was just an ULL.

so how do you tell the difference by looking at satellite, or is there a better way to quickly discern?

[wxmann_91]

If there is a lot of dry air wraping around a circulation on WV, it's probably an ULL.

It's really hard to tell whether something is a mid-level or low-level if it's a warm-core system. I'd use visibles and observations (or recon if available) to discern that.

[JonathanBelles]

something ive been wondering as well. cant wait for a 3-d satellite/radar!

[Wthrman13]

There are a number of visual clues that will tell you whether a circulation is primarily in the low, mid, or upper-levels. As already stated, if the circulation is clearly visible on WV imagery, it is almost certainly primarily in the upper-levels (although it may have a surface reflection that is less visible). Also, the clouds in upper-level lows are typically of the cirrus variety, whereas clouds associated with surface lows are typically cumuliform. Surface lows in the tropics are usually easily visible in visible satellite imagery, but are very hard to see (but not impossible if you know where they are) on conventional IR imagery. Bottom line, if you can detect the circulation easily on WV or IR, it's probably in the mid and upper levels. If you can only easily see it on visible imagery, it is probably a low-level circulation. Of course, for a tropical cyclone, the circulation is present at almost all levels, but is strongest in the lower levels.