The image below gives a general impression of what you'll see with WXSIM. (This image is not clickable, but there are better views available below).
To get a much clearer idea of what this program is and does, please view the
following, much more detailed screen shots. Each is from a sample run for Atlanta,
Georgia, made on November 8, 2003, unless otherwise indicated. NOTE: These images
are separate files, not inline images or web pages with their own 'back to home
page' features, so you'll probably need to use your browser's 'Back' button
after viewing them to see this page again.
Data entry form: This is where the user can enter
initial data and edit defaults. Note that most of the numbers displayed are
default values and calculations; you need to enter only a fraction of this data,
and most of it can be imported from METAR files downloaded off the internet.
Data output screen: This is the model's output, which
takes anywhere from a few seconds to a few minutes for the program to generate,
depending such factors as the time step and length of run specified by the user,
and of course the speed of the computer. The text/numeric data can be scrolled
to view every output time step (sometimes over 100). The graph is plotted as
the model runs.
Upper air data display: After a brief, initial "calibration"
run, the program displays its choices for upper air temperatures and dew points,
including a small sounding plot. The user can take this as is, or modify it
in consideration of RAOB soundings (black lines on plot) or mixed NGM and Eta
forecast data (gray lines on plot).
Advection options and entry form: This screen appears
just before the actual forecast run, to provide an opportunity for use of various
advection routines. Usually the best - and selected here - is the regional data
option (custom sites only), including the advanced option to import raw METAR
data, though the others can provide a quick approximation to reality in many
cases.
RAOB sounding data: The program can import TTAA data
for up to three surrounding RAOB sites' latest soundings, and then interpolate
and adjust for elevation differences to provide a representative RAOB sounding
for one's exact location (custom sites only), along with a few of the most commonly
used stability indices.
Data import form and FOUS graphical display: This
form is used to import raw METAR, RAOB (TTAA), and NGM and Eta FOUS data (custom
sites only). The graphs show interpolated FOUS data in the form of a weighted
average of the NGM and Eta output. Some of this data can be filtered into the
WXSIM model run with the "Use FOUS" option.
Interrupt planner form: This form is used to trigger
changes in a number of variables without the user needing to interrupt the program
during the forecast run (though this is still an option and several types of
changes are possible only through direct interrupts). This shot shows data derived
from GFS model meteograms on NOAA's READY site. The form may also be filled
out or edited by mouse clicks on the graph.
Data retrieval request form: Forecasts can be saved
to disk (registered version only) and then retrieved for detailed analysis.
This screen shows the output options available. Those checked were used to generate
the graphs in the next screen (below).
Display of retrieved forecast data: This is a sample
of retrieved data, specified in the previous screen (above). Notice that a sounding,
valid for the time marked by the mouse cursor, appears overlaid on the right.
Output screen showing winter precipitation event:
This is a "pretend" forecast for Zurich, Switzerland (note use of Celsius degrees),
showing the onset of winter precipitation. The onset itself was triggered by
a preset entry on the Interrupt Planner, but WXSIM itself made all the decisions
with regard to the type of precipitation. Note the initial mixture of rain and
sleet (ice pellets) as rain fell through layers of dry air aloft, changing to
all rain as the dry layer eroded, and then gradually mixing with snow due to
evaporative cooling and loss of daylight.
Output screen showing snowmelt, overnight radiation fog,
and solar eclipse: In this run for Peoria, Illinois, 6 inches of snow was
placed on the ground and the model was allowed to "free run" in clear weather.
The snow melts primarily during the day, and the resulting moisture combined
with strong radiational cooling over the snow cover at night produces early
morning fog (seen via the light blue "visible sky transparency line" on the
graph). As the snow melts, the surface albedo decreases, allowing a warming
trend. An interesting addition here is a total solar eclipse on Friday, cutting
into that day's high temperature and interrupting the warming trend.
Ouput screen showing land/sea breeze cycle: This
run is for a series of mostly sunny summer days in Sydney, Australia (note Celsius
degrees in use), at a distance of 2 km from the ocean, which lies ESE of the
site. Wind speed (in kilometers per hour here), and direction (in the standard
degrees east of north - also displayable as compass points such as "ENE") are
shown both in the text/numeric output box and as selected red flags on the graph.
Notice the light land breeze before dawn, followed by development and strengthening
of a sea breeze during the day, then weakening in late afternoon. Water temperature
has a climatological default value, but can be over-ridden by the user. Here
it was set at 21 C.
The WXSIMATE companion program for internet and home weather station data retrieval: This shows the main form, where you can specify which types of data to retrieve. Note here the data collected from a Davis Vantage Pro (TM) home weather station.
