Observations used to support RAMS
at the annual IBM stockholder's meeting
As part of the effort in developing forecasts, the results from the LAPS
pre-processing, assimilation step are analyzed as well as RAMS output.
Tools similar to those for RAMS were also developed for the study of LAPS
results. But since this step is critical to the application of RAMS as
well as other mesoscale models, the approach used for RAMS visualizations
has been applied to LAPS. These data were made available for interactive
three-dimensional visualization and analysis via a viewer application,
similar to the RAMS application described earlier. This includes all of
computed variables from LAPS at hourly resolution. Here is a some
sample image for Monday, April 27 at 1300 UTC (8 AM CDT). An animation
created with this application that includes this time step is available.
A surface variable (visibility) has been selected for display as pseudo-color,
which is overlaid on a topographic map. Rivers (blue) and coastlines
(black) are draped on the surface. An upper air variable (relative
humidity) has been selected for display via surface extraction. The
surface at 85% is requested in translucent tan as a representation of a
cloud boundary. Another field (temperature) has been selected to
show as a vertical slice, which is pseudo-color contoured. Any of
the three-dimensional fields available from LAPS can be visualized with
either of these methods. The upper air wind data are shown via streamribbons.
The seed points are along vertical profiles, which are specified interactively.
The upper air wind data can be seen along three vertical profiles, which
are specified interactively. The direction of the model wind field
along these "virtual soundings" are shown via vector arrows pseudo-colored
by horizontal wind speed. The length of the arrows also corresponds
to the horizontal speed. The profile is realized as a pseudo-colored
tube, which is contoured by the variable selected for isosurface realization
(i.e., humidity).
For comparison purposes, you can also look at satellite observations
from GOES-8 for this period in a color combination of the visible and two
infrared bands at 7:15 CDT on April 29. Animation of the available
observations can also be seen in a color combination of the visible
and two infrared bands and the visible.
Some of features visible in the RAMS predictions described earlier are
apparent.
For additional comparison, surface conditions for the region are shown
below for 6 AM CDT on April 29. Temperature and wind velocity are
depicted. An animation of these data for
the entire period is also available. Some of features visible in
the RAMS predictions described earlier are apparent.
Another depiction of the surface observations is shown below for an
hour later.
For additional comparison, radar observations for the region are shown
below for 6 AM CDT on April 29. An animation
of these data for the entire period is also available. Some of features
visible in the RAMS predictions described earlier are apparent.
A more detailed view of the radar data is shown below for 7:46 AM CDT
on April 29.
A different detailed view of the radar data is shown below for 7:47
AM CDT on April 29.
Radar observations can be used to remotely sense precipitation totals.
The image below illustrates estimates for the 24-hour period from 7 AM
CDT on April 27 to 7 AM CDT on April 28. The lack of precipitation
in the RAMS domain as predicted by the model is consistent with these observations.
lloydt@watson.ibm.com
