IWV and IWVF Events

As referenced in an earlier post, I have been working towards quantitatively describing surges with IWV and IWVF. I have tried many different approaches to this problem, such as:

(1) the aggregated value of the domain being greater than 95th, 90th, 80th, 70th or 50th percentiles
(2) sustained values of (1) for 2 and 3 consecutive days

Below are the 12 combinations of the above two critera for the year 1983. Titles for each plot are given above the respective plot.
Note: You can click on any graph to open up the full resolution version of the image in a new tab.

To test these 12 thresholds for accuracy, I compared them to a Hovmoller for precipitation (averaged over -116 to -107 longitude) for the same domain and same year (This figure will be shown below). From the precipitation Hovmoller, I chose 5 suspected events on days ~38, ~50, ~70, ~78 and ~120. I compared the above plots to see which, if any, produced events on roughly these same dates. From that, I observed that the IWVF thresholds produced better results than the IWV, note plots 1 and 2 (1 day of >=90th percentile for IWVF and IWV, respectively). Overall, it appeared that 1 day of IWVF >=95th percentile, plot 3, and two consecutive days of IWVF >= 90th percentile, plot 5, produced the best results. These two plots will be highlighted below and compared to the Hovmoller of precipitation mentioned earlier.
It is my judgment, that for this year the two consecutive days of >=90th percentile threshold produced better results. To provide a better view of exactly what this threshold is describing, below is a comparison of 'events' in this criteria to a Hovmoller of IWVF for the same time period and domain.

It seems clear that this threshold limit is picking-out the more statistically significant periods of IWVF. Now, to show the relationship between IWVF and precipitation, below are IWVF and precipitation Hovmollers for same temporal and spatial extents.

There does seem to be a rather nice agreement between this two parameters (precipitation surges seem to be associated with high values of IWVF). So, I got that going for me...which is nice.

Hopefully, this will be an accurate and clean way of describing this "Gulf Surges" in the North American monsoon.

-jamie