Determing is LLC (low-level circulation) has developed?

[ticka1]

Is there anyway an amatuer like me can review the Invests that are posted to determine if an LLC has developed? Until this criteria is established - most of the times we are just watching a blob (need better terminology).

Advice, comments and suggestions welcome.

[jfranklin]

Determining the surface (or low-level) flow is very difficult. There are a number of tools that are used, and some are easier to interpret than others. The simplest is to look at high resolution satellite loops and follow the motion of low clouds, if they are visible. This is almost impossible at night, but there is a combination of channels known as the "night-vis" that can sometimes reveal low cloud lines. The QuikSCAT scatterometer gives surface wind, but this is an extremely difficult kind of data to interpret because it does not give a wind, but at each grid cell gives a choice of 2-4 possible winds. These are called "ambiguities". You may have seen QS analyses with single vectors shown - this is simply the result of an automated algorithm choosing particular ambiguities. The choice is always wrong. There is no way to properly interpret QS data without looking at all the ambiguities in the context of other available data (such as ship reports or low-cloud motions) and coming up with your own analysis. An inexperienced analyst has almost no hope of getting it right.

The best way to determine the existence or lack of existence of a closed circulation center in these uncertain cases, however, is to send an airplane in to actually measure the winds directly. With the new C-130J aircraft, it has recently become possible to relay the high-density obs (MINOBS) from the aircraft and post them on the web - these are now on our web site in real time, so people can follow along with the progress of a recon mission at homw and not have to rely on infrequent RECCO messages.

The short answer to your question, though, is generally no.

James