1
2	Aircraft begin collecting weather observations in 1919
3	Weather Balloons Replace Aircraft in the Early 1940s
4	Aircraft Weather Data Regains Popularity in the 1960s The use of modern navigation and communication systems in the 1960s and 1970s sparked renewed interest in the use of aircraft to measure and report meteorological data. ACARS (Aircraft Communications, Addressing, and Reporting System) was first used to relay wind and temperature data in support of the Global Weather Experiment in August 1979.
5	ACARS – What is it? A communications system used by many airlines to send data to and from their aircraft Uses VHF radio over land areas and satellites over the oceans Transmits aircraft performance, passenger information and gate assignments, in addition to weather data While aircraft weather data is often commonly referred to as “ACARS”, it is also known as “MDCRS” (Meteorological Data Collection and Reporting System) and “AMDAR” (Aircraft Meteorological Data Report)
6	Sources of Aircraft Weather Data
7	Real-time Data Becomes Available to Meteorologists Airlines agreed to allow NWS, airline and university meteorologists to use ACARS (MDCRS) data in 1997. Access is via a web page hosted by the Forecast Systems Laboratory http://acweb.fsl.noaa.gov
8	Aircraft Data Available on AWIPS NWS meteorologists also receive ACARS (MDCRS) on their AWIPS workstations. The data currently consist of temperature and wind speed and direction.
9	NWS and UPS Work Together to Collect Water Vapor Data From Aircraft The NWS and United Parcel Service (UPS) tested a sensor to measure water vapor from 1999-2001. Details are available at http://ams.confex.com/ams/pdfview.cgi?username=30088 The NWS and United Parcel Service are evaluating a new water vapor sensor at the present time.
10	Meteorological Applications Many airline and NWS meteorologists have found ACARS/MDCRS data very useful in producing more accurate forecasts and warnings. Read about some recent applications at http://acweb.fsl.noaa.gov/docs/fcst-disc/?O=D