The ITWS Runway Wind Nowcast Product
The Runway Wind Nowcast Product will support the ITWS objective by providing short term (up to 30 minutes) forecasts of the tailwind and crosswind components of the horizontal wind over each runway at an ITWS airport. These forecasts will enable FAA users to better anticipate wind shifts impacting runway usage and trajectories of approaching and departing air traffic. They may also support future ITWS products such ceiling and visibility nowcasts. Our initial development efforts, which are reported here, have been directed toward Orlando International Airport (MCO) as the product request originated there. However, in the near future we plan to expand the scope to include other ITWS airports including Memphis. The Runway Wind Nowcast Product is being developed to help Air Traffic Control (ATC) personnel answer the following question: Do we need to change runways? That would become necessary if tailwinds or crosswinds exceed usage thresholds. At most US airports, with dry runways, tailwinds much be less than five knots and crosswinds must be less than 15 knots. Other, lower thresholds apply if the runways are wet. However, these thresholds are subject to local modifications. For example, the MCO tailwind threshold for dry runways is 7 knots. The decision faced by ATC personnel seems, at first, to be clear cut: if the tailwind or crosswind exceeds nominal thresholds, use of that runway must be discontinued. The problem (at least at MCO) is that most threshold crossings are very brief. So, it may be better to temporarily hold traffic than to switch runways. Reliable (i.e., accurate and precise) short term forecasts will help ATC personnel make better hold-or-switch decisions.