[gembud] Plotting obs with various ob times

Hi,

I am trying to create regional surface plots using both METAR and various
mesonet obs.  The mesonet obs all have varying reporting frequency, so
observation times are all slightly different.   For example, at 01Z, the
date/times of the mesonet data I'm looking to plot on the map may look like
this:

TS645    140313/0050
CSBT2    140313/0053
PXWT2    140313/0053
EW0792    140313/0101
FDST2    140313/0103
DW5244    140313/0103
PJNT2    140313/0038
EMNT2    140313/0038
RPILAS    140313/0102
ESCOND    140313/0102
VNHRN    140313/0105
PGPT2    140313/0100

While it seems 'dcmetr' is smart enough to round up METAR reporting times
(e.g., 0054 becomes 0100), it seems that sfedit and sfmap take the "DATTIM"
variable quite literally.  If I ask it to plot data from 140313/0100, in
the above example, all I'd get are the METAR sites and the one mesonet
station, PGPT2.  If I set DATTIM to a range (140313/0035-140313/0105) with
DEVICE set to 'XW' ... I'd get a quick animation with one frame for each
unique report time.  With the GF or GIF device, my plot would only contain
one surface ob, station 'VNHRN'.  I'd the get the same results if I set
"DATTIM = latest".

Is there a 'hidden' feature in sfedit or sfmap that I'm just not seeing?
I'd like to be able to create a single plot with just the latest available
ob available from all the stations, as long as they are within a certain
range from the requested time.

For example, I'd like to specify "140313/0100" but get a plot that contains
the latest obs for each station, assuming the latest obs are no older than
say, an hour.  All the ob times listed in the example would be included
because they are "close enough" to 01z.

I haven't been able to find an "easy" way to do this.  I'm guessing my only
option is to fudge the observation times (round them up or down to the
nearest hour) before pushing the obs through sfedit.

Does anyone know of a better option?

Thanks,
-Mike Hardiman