Corridor Integrated Weather System (CIWS)

CIWS Precipitation forecastCIWS domain real-time precipitation forecast.    Full size

The U.S. air transportation system faces a continuously growing gap between the demand for air transportation and the capacity to meet that demand. The air carrier transition from turboprops to regional jets, use of reliever/secondary airports, and post 9/11 business jet traffic growth have significantly increased high altitude en route traffic congestion. As a consequence of this high altitude congestion, severe en route convective weather is now a major factor in thunderstorm season air traffic delays. 

Efficient and safe management of en route air traffic when thunderstorms arise requires very accurate, low-latency, high-resolution three-dimensional (3D) weather information and forecasts.  A Corridor Integrated Weather System (CIWS) demonstration was initiated by the FAA in 2001 to determine experimentally the operational utility of improved current 3D weather information and 0-2 hour forecasts in the highly congested Great Lakes and Northeast Corridors regions. From this successful beginning, the system evolved rapidly and current plans call for the expansion of CIWS to cover the continental U.S. and southern Canada in June 2008. Figure 1 shows the envisioned sensor inputs and operational users of CIWS by 2011.

Air traffic on clear weather day Figure 2: Air traffic on clear weather day. The 2007 CIWS domain is shown in white. The ongoing CIWS Reengineering effort permits a larger domain size by June, 2008.

Weather-related air traffic delays are most significant in areas where there is already significant congestion in fair weather. The CIWS 2007 coverage area (outlined in white in Figure 2) includes all of the seven major “bottle necks” identified in the FAA Airport Capacity Enhancement (ACE) Plan (2001).  (The U.S. air traffic density depicted in Figure 2 occurred during the 24-hour period from 0900 UTC on 14 May, 2007 to 0900 UTC on 15 May, 2007.)

CIWS Weather Products

The CIWS 3D weather depiction is composed of two main product types: Precipitation [vertically integrated liquid (VIL)] and Echo Tops. Slideshow 1 illustrates examples of these six products.

CIWS Benefits

The delay reduction benefits of CIWS in 2005 exceeded 90,000 hours of direct delay with an airline direct operations cost savings in excess of $90 M per year.  Work is underway to provide national coverage by the Lincoln-operated CIWS demonstration system in 2008.  The CIWS technology developed by the Laboratory is being transitioned to an operational CIWS system to be operated by the FAA’s William J. Hughes Technical Center (in Atlantic City, NJ) starting in 2011.

Additional uses of CIWS

In addition to further improvements in both tactical and automated strategic convective weather forecasts [especially the Consolidated Storm Prediction Algorithm (CoSPA)], CIWS is being used for integrated weather-air traffic management (ATM) decision support tools development and the National Airspace System operations benefits analyses.  CIWS data is being used to develop models of pilot avoidance of storms as well as models for route and sector capacity in convective weather.  The Route Availability Planning Tool (RAPT) accesses the CIWS forecasts to improve the ability to provide route availability guidance in en route airspace surrounding the NY terminal area. CIWS also supports other programs, such as the System Wide Information Management (SWIM) program and the NextGen Network Enabled Weather (NNEW) program. CIWS data is used broadly as an information source for NextGen Architecture prototype testing.

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