Aviation Products

The Experimental ADDS project was successfully completed on June 30th, 2015. All research has now been transferred to Operational ADDS.  Please consult that site for all of your future aviation... more

ADDS display of clear-air turbulence
Left: Regional view of current ceiling conditions as shown by RAL's newly-operational Ceiling and Visibility Analysis product. Right: Magnified sub-regional view indicating possible terrain... more
National Ceiling and Visibility Analysis (NCVA)

The Helicopter Emergency Medical Services (HEMS) Tool has been specially designed to meet the needs of low-altitude VFR emergency first responders. It runs as a desktop application on your... more

HEMS browser product display

Recognizing that probabilistic weather forecasts are critical to meeting the air traffic efficiency goals of NextGen, RAL is working under FAA sponsorship to develop a probabilistic 1–10 hr C&... more

Ceiling and Visibility Forecast Product (CVF)
The above photo shows the Juneau International Airport and Gastineau Channel. The patches of churning water seen in multiple areas of the channel give an indication of the strength of the northerly... more
Juneau Airport Wind System (JAWS)
ADDS Website

Our work in aviation weather dissemination continues through participation in the FAA ADDS (Aviation Digital Data Service) and NNEW (NextGen Network Enabled Weather) Programs. The ADDS... more

Operational Aviation Digital Data Service (ADDS)

The primary role of the nowcast environment is to collect weather data, execute algorithms for producing a combined thunderstorm forecast, and provide a graphical display tool for viewing the... more

Cidd is a X-based, real-time data display application which supports PPI, CAPPI, and cross sectional views. Cidd is the main display tool within the Auto-Nowcast Environment. It is highly configurable and is used to display the majority of the MDV and SPDB formated data produced within the Environment.

TITAN is a real-time algorithm for automated identification, tracking, and extrapolation based short-term forecasting of thunderstorms utilizing volume-scan weather radar data.  For each time step... more

Thunderstorm Identification, Tracking, Analysis, and Nowcasting (TITAN)
FINECAST® Nowcasting System: High Resolution AnalysisImproving Nowcasting via Data Assimilation

Fine-Scale Analysis and Nowcast System (FINECAST®) is used by the research community to study... more


VLAS represents the Doppler lidar variant of VDRAS.  VLAS provides very high-resolution wind information at the neighborhood scale and has been used to study atmospheric transport and diffusion in... more

Variational Lidar Assimilation System (VLAS)

The National Convective Weather Forecast (NCWF) product was developed by NCAR/RAL and eventually operationalized by the NWS Aviation Weather Center (AWC).  It was the first extrapolation-based... more

National Convective Weather Forecast Product (NCWF)

Named after the Native American Chief Niwot, this new short-term forecasting system is being developed based on a blending of observation extrapolation technology and numerical weather prediction... more

Map of Taiwan

Advancements in science and technology, particularly computer and networking capacity, have allowed many civil aeronautics authorities to expand and modernize their aeronautical... more

AOAWS Display
USDA Avian Radar EvaluationSince 1988, >219 people have been killed after aircraft bird strikes, worldwide Bird/wildlife encounters cost U.S. civil aviation >$600 million/year USDA responsible... more
Avian Radar Target Simulator

The Current Icing Product (CIP) combines sensor and Numerical Weather Prediction model output to provide an hourly, three-dimensional diagnosis of the icing environment. The Forecast Icing Product... more


The Current Icing Product (CIP) combines sensor and Numerical Weather Prediction model output to provide an hourly, three-dimensional diagnosis of the icing environment. The Forecast Icing Product... more


DCIT EDR output at FL370 for 00 UTC 5/14/09; (Bottom) blowup image of the upper Midwest showing overlaid 1–hr in situ EDR tracks validating the DCIT diagnosis. (Note that there are temporal... more

Diagnose Convectively–Induced Turbulence (DCIT)
Example of GTG 2–hour turbulence forecast as it appears on the Operational ADDS web site.

Over the last several years the FAA has funded NCAR and others to develop a turbulence nowcast and forecast... more

Graphical Turbulence Product (GTG-3)
Coverage provided in a 24 hour period of in situ EDR measurements (colored code in units of m 2/3 s -1) from UAL mostly 757–200 aircraft (top panel), with one–minute routine reporting and DAL 737–800... more
In Situ Turbulence Diagnosis

The LLWAS system was originally developed by the FAA in the 1970s to detect large scale wind shifts (sea breeze fronts, gust fronts and cold and warm fronts). It was developed by the FAA in... more

Low-Level Wind Shear Alert System (LLWAS)
NASA Icing Remote Sensing System (NIRSS) 

The NASA Icing Remote Sensing System (NIRSS) deploys a vertically–pointing K–band radar, a lidar ceiliometer, and a profiling microwave radiometer to... more

NASA Icing Remote Sensing System (NIRSS)
NCAR's demonstration system merges NTDA output from multiple radars to form a 3–D turbulence map, revealing regions of moderate and severe turbulence within clouds and thunderstorms.166 FAA, NWS and... more
NCAR Turbulence Detection Algorithm (NTDA)

The Research Applications Laboratory is addressing oceanic weather needs for aviation through the development of an intelligent system that generates 0-2 hour nowcasts.

Remote, oceanic... more

Oceanic Convection and Nowcasting Hazards
Radar-based Wind Shear Alert System

Wind shear experts in RAL provide consultancy services to public and private organizations and governments around the world to help them understand wind shear... more

Radar-based Wind Shear Alert System
Windshear and Turbulence Warning System - Hong Kong

An operational Windshear and Turbulence Warning System (WTWS) was developed for Hong Kong's NewAirport at Chek Lap Kok. The WTWS provides alerts... more

Windshear and Turbulence Warning System (WTWS)

Thunderstorms and especially lightning pose a safety risk to people outdoors whether they are working or enjoying themselves with recreational activities.  It is imperative to bring people inside... more

BoltAlert® lightning potential (high risk in magenta) and actual strikes.
The FAA and NCAR are working to solve the Aircraft Ground Icing Problem.

The accumulation of ice on aircraft prior to take off has long been recognized as one of the most significant safety hazards... more

Weather Support to Deicing Decision Making (WSDDM®)

The Next Generation Air Transportation System (NextGen) is a national priority designed to meet the air transportation needs of the US in the 21st century—in particular, a significant growth in... more

Consolidated Storm Prediction for Aviation (CoSPA)

Controlling snow and ice buildup on roadways during winter weather events presents several challenges for winter maintenance personnel. Among these challenges is the need to make effective winter... more

WRF Model Output

The Weather Research and Forecasting (WRF) Model is a next-generation mesoscale numerical weather prediction system designed to serve both atmospheric research and operational... more

WRF model output showing simulated radar reflectivity (dBZ) for Typhoon Mawar at 3.3-km (2.1-mi) grid spacing. Time period is from 0000 UTC 22 August 2005 to 0000 UTC 24 August 2005.

The Dynamic Integrated foreCast (DICast®) system is tasked with ingesting meteorological data (observations, models, statistical data, climate data, etc.) and producing meteorological forecasts at... more

DICast® System
Gridded ForecastingSample image of the surface air temperature generated by GRAFS at 21 UTC on April 8, 2009.

GRAFS (GRidded Atmospheric Forecast System) is a software system that is designed to... more

LOGICast™ software system

The Radar Icing Algorithm, or 'RadIA', utilizes the polarized moments from the National Weather Service's network of WSR-88D operational radars and the most recent Numerical Weather Prediction... more

Radar Icing Algorithm

An icing hazard receiving increased attention lately is that of the ingest of large amounts of ice crystals into jet engines, causing them to fail during flight. As of this time, no accidents have... more

In-Flight Icing Product Development Team

The FAA's Aviation Weather Research Program (AWRP) directs research and development activities for 11 Research Teams. The roles of the InFlight Icing... more

Experimental Icing Product Alaska - IPA

Aviation-based winter weather research at RAL, sponsored by the Federal Aviation Administration, has focused on developing two new systems in support of Ground Deicing operations. The Liquid Water... more

When an aircraft experiences winter precipitation conditions on the ground, it is required to undergo a de/anti-icing procedure involving glycol-based fluids before takeoff. In order to determine... more

NCAR Checktime Display

CubeView is a data viewer reference implementation utilizing data and standards from the 4-D Weather Data Cube. CubeView displays data provided to the 4-D Cube by the NOAA National Weather Service... more

The Flight Path Tool (FPT) is a comprehensive, interactive, geographical display that brings together all of the weather products available on ADDS. It runs as a desktop application on your... more

Flight Path Tool

RTFDDA-LES extends real-world numerical weather prediction to large-eddy-simulation (LES) scales, with grid sizes down to ~30m. The NCAR WRF-based RTFDDA system is formulated for simultaneously... more


The National Convective Weather Forecast (NCWF) product, designed and implemented by the National Centerfor Atmospheric Research (NCAR), provides a diagnose of the current locations of convective... more

National Convective Weather Forecast 2 (NCWF2)

The Remote Oceanic Meteorology Information Operational (ROMIO) Demonstration is a project sponsored by the FAA’s Weather Technology in the Cockpit (WTIC) program.  It is focused on... more

Remote Oceanic Meteorology Information Operational (ROMIO)

FastEddy limited area domain simulation with the cell perturbation method for resolved turbulence instigation (top) versus a periodic domain reference simulation (bottom). This feature allows... more


Because of their light weight, slower air speed and limited endurance, most small Uncrewed Aircraft Systems (UAS) are much more susceptible to variations in wind speed/direction and turbulence... more

Since it is a forecast product, the GTG is most useful for route planning, i.e., strategic avoidance of turbulence. However, given the rapidly evolving character of turbulence, for tactical... more

Example of a GTG turbulence forecast as it appears on the Operational Aviation Weather Center web site.
Real-Time, Cutting-Edge Weather Hazard Information

The Global Weather Notification system is a novel way to provide pilots with real-time, cutting-edge weather hazard information and to keep them... more

Global Weather Notification system