Simulated Weather Imagery (SWIm) | Purpose | Gallery | Cases

Visually and physically realistic sky (and land) simulations are being produced from real-time weather data. In this case a 3-D hydrometeor (cloud) analysis (from an updated version of the Local Analysis and Prediction System - LAPS), runs over a Colorado 500 meter resolution domain every 10 minutes. The analysis uses GOES-16 satellite ABI data (including 2km resolution IR and 500m resolution visible imagery), METARs, radar, aircraft and model first guess information to produce 3-D fields of cloud fraction, cloud liquid, cloud ice, rain and snow. Surface spectral albedo is derived from NASA's Blue Marble Next Generation imagery, augmented with a snow cover analysis. The 500m grid resolution takes advantage of the 500m satellite resolution in the visible wavelengths. The gridded fields are then converted using a ray-tracing technique into an all-sky image. More details are in this satellite data workshop (JCSDA) presentation. A 2014 ESRL news story on this work has been posted. Overall, visualizations are being tested with analyses of present weather from LAPS & GSI along with forecasts from LAPS, FIM, CSU/RAMS, NAVGEM, and HRRR. Preliminary camera assimilation work is being done with the GSI analysis. Other variational assimilation (4DVAR), directly using visible and IR radiance information (e.g. at a 1-minute cadence) from cameras and satellites in a tomographic fashion is being proposed for use in various systems.

The image above on the left is simulated from an analysis of 3D hydrometeors using GOES ABI and other data. Aerosols are specified via namelist. The image on the right is from an EKO Instruments all-sky camera located at CIRA (at Colorado State University in Fort Collins) at the same time. In each fisheye lens view the zenith is in the center and north is up. The color balance of the simulated image is set to reproduce the "actual" colors/radiances when the display white point is set to closely match the sun. Thus to see a true apples to apples comparison (if for example you take your computer outside or right by a window), please set your display to a color temperature of 5780K (the sun's white color above the atmosphere). Some images are shown a bit dark to avoid saturating and losing details on the bright end. This can be compensated for by turning up your monitor brightness, thus showing a broader dynamic range.

Select Site — DSRC | NREL | CIRA | RadioMetrics | BAO Tower | Pikes Peak | Mount Evans

Latest all-sky comparison image | mask (site is CIRA)

Latest comparison animations (site is CIRA): Polar | Cylindrical


In these 360 degree panoramic (all-sky) views, a simulated LAPS image is shown (top) compared with a remapped camera image (middle) from an EKO all-sky camera installed at CIRA. The bottom image is the ratio between the two (camera / simulated). South is at the center of each image and north is at the edges. The listed solar irradiance is calculated from the same radiance information used to construct the image.

(Moore Tornado)

Archive Directories (site is CIRA): Raw Camera | Polar Camera | Cylindrical Camera | Polar Comparison | Polar Blinking | Cylindrical Comparison

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More visualizations are on my main home page | Contact: Steve Albers (Steven.Albers@colostate.edu)