Question

We're getting negative GRVT values for all times (P1-P6) and are
wondering if we're using the table template incorrectly.


Answer

It is unlikely that I would choose a case study that is undergoing
cyclolysis (cyclone death and decay) through the entire period of
interest. It is likely that the lat/lon of your 1000 hPa level
cyclone center is incorrect and quite possible that it is a result
of incorrectly using the table template.

Recall that the second column (heading "6-h Cyclone lat/lon (Time
+ 6-h) is the PREDICTED 1000 hPa level cyclone center six hours
AFTER the time listed in the first column.

So, as an example, the lat/lon position you place next to the P2
row (t0+6h) is where you expect the 1000 hPa level cyclone center
to be at P3, but you are using GAVA, nearly LTHAD, LAD, and LDIA
maps from P2 to calculate whether you expect cyclogenesis or
cyclolysis to occur at the position of the cyclone center at P3.

Review what you did in the tables of Project #9 where you used the
"final" cyclone lat/lon position to determine if the GAVA, 
nearly LTHAD, LAD, and LDIA at the "inital" time were contributing 
to cyclogenesis or cyclolysis at the "final" cyclone position.