5 December 2000: Dan Baumgardt, SOO in LaCrosse, WI and Phil Schumacher, SOO in Sioux Falls, SD
have made significant improvements to the AWIPS ingredients maps.
Dan's Volume Browser Localization Page
includes the new AWIPS Winter Ingredients-based
Methodology fields. These fields include EPV* (i.e., PVes, or Saturated Equivalent
Potential Vorticity) and QPV. They are combined onto the following
AWIPS Ingredients Maps. Many thanks Phil Schumacher for creating the EPV* field and to Dan
Baumgardt for computing QPV and assembling the diagnostics into these nice plots.
These new maps overcome many of the limitations that the pseudo-ingredients (discussed below)
suffered from. It is recommended that the new Baumgardt maps be used instead of those
presented on this page.
Important Notes (Please read before downloading the AWIPS procedures):
AWIPS pseudo-ingredients maps suffer from a number of limitations
and are inferior to the NTRANS or GEMPAK ingredients maps.
Some of these differences are due to problems inherent in AWIPS and
some are due to my lack of expertise (and lack of time to gain the
expertise) to code up some of the computed quantities.
The primary reason that I am making the AWIPS pseudo-ingredients maps
available is not for operational use but for skilled AWIPS users to
improve upon them and hopefully share their improvements with others.
Some of the shortcomings of the AWIPS pseudo-ingredients maps are listed below:
- Equivalent potential vorticity (PVe) is used in place of
saturated equivalent potential vorticity (PVes). Where PVe
is negative, the atmosphere can be characterized by PI or PSI, but
conclusions about CI and CSI cannot be drawn.
- The convection potential indicator, QPV, is not shown on the maps.
- Contour intervals and ranges are somewhat arbitrary and are determined
automatically by AWIPS. Problems associated with this include:
- Negative and positive contours of Q-vector divergence are shown.
In Gempak, only negative contours are shown to indicate regions of
forcing for upward vertical motion without cluttering the map.
- Colored (filled) contours can be very misleading. Even though
I developed the colormaps for a specific range of values, AWIPS automatically
adjusts the starting and ending points of the colormap based on values
present on the given fields. For example, although the temperature colormap
was designed to shade the regions where temperature is
between 0 and -20C, the actual
range of temperatures shaded will vary. This is particularly troublesome
when used operationally because a forecaster needs a consistent
color range that doesn't vary day-to-day or model-to-model.
- Overall aesthetics and readability are not at the level of NTRANS/Gempak.
|Example of an AWIPS pseudo-ingredients map:
|(click to enlarge)|
Key to the AWIPS Pseudo-Ingredients Plots:
|(1) 6-hour Forecasted Precip
(1) PVe (NOT PVes)|
2) Q-vector Divergence
|Temperature||(1) Relative Humidity |
(2) Specific Humidity
Once you have read and understand the above limitations, you may
download the ETA AWIPS pseudo-ingredients procedure files:
"awipsPseudoIngredients.tar". This a tarred file containing four directories, "Ingredients 600mb ETA", "Ingredients 700mb ETA", "Ingredients 850mb ETA", and "colorTables." After un-tarring the
file (tar -xvf awipsPseudoIngredients.tar), these
directories should be placed where your machine looks to find procedures.
On our machine at UW-Madison it is a different directory than on the
NWS machines, so I do not know the NWS location exactly. One source told
me that these procedure directories at the NWS are in "/data/fxa/procs".
Any additional information is welcome.
Download the ETA AWIPS pseudo-ingredients procedure files