NOAA DAFS In-Flight Icing CONUS

Description

DAFS IFI CONUS is NOAA/NCEP's Domestic Aviation Forecast System in-flight icing product for the contiguous United States. DAFS became operational as a standalone aviation forecast system on March 30, 2026, producing HRRR-based aviation hazard guidance through the Unified Post Processor. In GribStream, dafsificonus exposes the 3 km CONUS in-flight icing feed mirrored from NOMADS.

The dataset contains IFI v2.0 guidance for icing probability, icing severity, and supercooled large droplet potential. NOAA's official notes highlight several science changes in IFI v2.0, including explicit liquid water content in the main icing calculation, total water content for cloud-boundary identification, and treatment of explicit model supercooled rain as an indicator of SLD potential. The product is published on 60 vertical levels every 500 ft from FL010 through FL300, which makes it useful for altitude-specific route planning instead of only broad icing-area awareness.

Common uses include in-flight icing map layers, route and altitude screening, airport-area icing context, dispatch tools, and applications that need to distinguish icing probability from severity and SLD risk. For turbulence diagnostics, use DAFS GTG. For full atmospheric profiles, freezing-level context, winds, temperature, humidity, and cloud diagnostics, pair this product with HRRR or RAP.

Detail

• Archive window: Last 3 days
• Product inventory: NCEP DAFS products
• Operational source: NOAA NOMADS DAFS
• Operational notice: NWS SCN 25-80
• Resolution: 3 km CONUS Lambert grid
• Forecast cadence and length: hourly steps from 1 to 18 hours
• Vertical coverage: 60 levels every 500 ft from FL010 to FL300
• Core fields: icing probability, icing severity, and supercooled large droplet potential
• Companion datasets: DAFS GTG, DAFS IFI Alaska

Parameters