Steve Albers (left) and Kirk Holub with All-Sky Cam Steve Albers (left) and Kirk Holub with All-Sky Cam
ESRL Global Systems Division researchers Steve Albers (left) and Kirk Holub with All-Sky Cam atop the NOAA Boulder roof. This 180-degree, "fish eye" lens captures live images that are compared to weather model images from the same geographical perspective. (Photo credit: Will von Dauster, NOAA)

All-Sky Cam Looks Up – Helps NOAA Refine High-Res Weather Models

19 March 2014

If you really want to know what’s up in Boulder – and get an update every 15 minutes – check out a website from NOAA's Earth System Research Laboratory (ESRL) that displays real-time observed and simulated images of the sky over the city.

The real sky images are from an “all-sky camera” that ESRL installed on the roof of the David Skaggs Research Center, NOAA’s home in Boulder. The All-Sky Cam features a 180-degree “fish eye” lens. It’s cool to see the “real” sky image next to the modeled version, but the All-Sky Cam’s greater value is in helping to improve short-term forecasts of severe weather, such as thunderstorms and tornadoes.

The simulated images show the sky from the same geographical perspective as All-Sky Cam, but are created from a high-resolution digital copy of the three-dimensional atmosphere made by ESRL’s Local Analysis and Prediction System (LAPS). Every 15 minutes, the LAPS model is generated by computer using weather observations, including meteorological radars and satellites. LAPS is a publicly available, highly portable and adaptable weather analysis and forecasting system developed with national and international collaborators, and can be run at any location as needed.

Because LAPS is not yet using the observed all-sky image in its analysis, a visual comparison of the observed and simulated clouds offers a subjective test of the quality of the LAPS 3D analysis that is useful to researchers, while also of interest to the public. Visitors to the website can compare the LAPS model output with the actual all-sky camera imagery. The observed and simulated all-sky images are shown as 360-degree panoramic views on the site.

Short-term weather forecasts (zero to three hours) of high-impact weather events such as thunderstorms and tornados critically depend on how realistic the analysis fields are. By comparing the actual and simulated images, researchers can improve the LAPS analysis.

NOAA works with partners, including the Longmont Astronomical Society and the Meyer-Womble Observatory on Mount Evans, to produce similar comparisons from different geographical viewpoints. NOAA scientists hope to expand these observations into a national network and use the observed all-sky imagery to improve the quality of LAPS analyses and short range severe weather forecasts. Once refinements are made, the simulated all-sky images or time loops could be used as weather guidance for emergency operations (e.g., response to natural disasters) and onboard small aircraft for navigation.