Narrative:

Charlotte meter position utilizes several weather tools to assist in determination of airport operation direction and arrival rate/capacity. Specifically wind direction directly relates to a north or south operation and the associated aar (airport acceptance rate). Additionally the need for accurate and precise wind information is directly related to ATCT tower operations and anticipated airport volume/ demand. One tool is itws (integrated terminal weather system) weather monitor that is installed in the clt ATCT and ZTL tmu. The clt itws was showing wind of 120/10 KTS - the clt metar/ASOS was showing 07009g20 KTS. The itws wind was 50 degrees out of sync with the actual winds on the airfield. Several times the clt tmc was preparing to change direction of operation based on the itws winds. This would have placed aircraft landing with a significant tail wind for a south operation at clt. The itws consistently shows a large difference in direction of the winds and speed when compared to the actual metar on the clt airport. This is a recurring situation for the charlotte operation. The problem was brought up to the cwsu and the itws sensor was checked; however the problem remains of incorrect data on the itws. The clt itws sensor and/or programming need to be check for consistency to match the reported airfield winds.

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Original NASA ASRS Text

Title: ZTL Controller voiced concern regarding weather tools available to ATC and the wind reading inaccuracies that sometimes occur.

Narrative: Charlotte Meter Position utilizes several weather tools to assist in determination of airport operation direction and arrival rate/capacity. Specifically wind direction directly relates to a North or South operation and the associated AAR (Airport Acceptance Rate). Additionally the need for accurate and precise wind information is directly related to ATCT Tower operations and anticipated airport volume/ demand. One tool is ITWS (Integrated Terminal Weather System) weather monitor that is installed in the CLT ATCT and ZTL TMU. The CLT ITWS was showing wind of 120/10 KTS - The CLT METAR/ASOS was showing 07009G20 KTS. The ITWS wind was 50 degrees out of sync with the actual winds on the airfield. Several times the CLT TMC was preparing to change direction of operation based on the ITWS winds. This would have placed aircraft landing with a significant tail wind for a south operation at CLT. The ITWS consistently shows a large difference in direction of the winds and speed when compared to the actual METAR on the CLT airport. This is a recurring situation for the Charlotte operation. The problem was brought up to the CWSU and the ITWS sensor was checked; however the problem remains of incorrect data on the ITWS. The CLT ITWS sensor and/or programming need to be check for consistency to match the reported airfield winds.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.