I ran the ForecastBuilder procedure for a 24 hour period to change
the precip mode from stratiform to showers, letting the procedure run
its course beginning with the Precipitation Types and Accumulation
Grids step. Since this was in the extended portion of the forecast,
there were no accumulation grids, and precip type in our area was
simply rain showers. Upon completing the MergeWx portion of the
procedure, I ended up with the attached split Wx grid. The PoP grid
covered the full 6-hour period, but the Wx grid was split into a
1-hour grid and a 5-hour grid. The 1-hour Wx grid matches the PoP, but
the subsequent 5-hour grid had the Wx categories (SChc and Chc)
inverted from what they should be based on the corresponding PoP grid.
I reran just the MergeWx portion of the procedure again multiple
times, with the following results:
- Same 24-hour period => Same result
- Just the 6-hour period in question => 2 grids (1-hour and
5-hour) were still produced, but the Wx categories were correct in both.
- A 12-hour period ... the 6-hour period in question and the
following 6-hour period (PoPs increased to Chc range in the
2nd 6-hour period. 6-hour PoPs also attached for reference) =>
Same result as the 24-hour period. NOTE: This second 6-hour period
was also split into 2 Wx grids despite no change in precip type.
These two grids were identical, though. I've also attached this Wx
grid for reference.
(Edited: Images were attached out of order, so will
place Wx/PoP grids for 2nd 6-hour period in reply for clarity.)
