Weather Observer Org

13/10 :  New ASOS Sensor Improves Wind Measurements

   New ASOS Sensor Improves Wind Measurements

The Automated Surface Observing System (ASOS) Product Improvement Program will deploy a replacement wind sensor beginning this month. The new sensor, known as the Ice-Free Wind (IFW)sensor, will report wind information using the three-second World Meteorological Organization gust standard.
ASOS Ice Free Sensor
The new ASOS wind sensor, the Vaisala 425NWS, is a sonic anemometer with no moving parts.

The current ASOS wind sensor, the Belfort 2000, uses rotating cups to measure wind speed and a vane to measure wind direction. Over a two-minute period ASOS uses 24 five-second averages to determine the two-minute average wind speed and direction. Every minute ASOS stores the highest five-second average speed for the past minute, along with its direction, in the 12-hour archive for additional processing. This highest speed value is used to determine if a gust and/or a peak wind remark will be reported.

The new ASOS wind sensor, the Vaisala 425NWS, is a sonic anemometer. It has no moving parts and is designed to operate better in winter weather conditions. As with the Belfort sensor, over a two-minute period, ASOS uses 24 five-second averages to determine the two-minute average wind speed and direction. But the highest three-second running average speed is stored for gust and peak wind processing.

While there will be little difference in two-minute average wind speed and direction reporting, the changes in gust and peak wind reporting may be significant. "The mass of the moving parts in existing sensors limits responsiveness. The new sensor will be more responsive to short-term gusts," according to Rick Ahlberg, ASOS Product Improvement Manager, NWS Office of Science and Technology. "We can expect to see more gusts and peak winds reported with the new sensor."

The IFW sensor will be deployed at all ASOS locations over a 9-month period beginning this month. More specific information will be issued by the responsible weather forecast office for each individual site when the IFW is implemented.

More information on IFW implementation plans and status can be found on the surface observation program web page at http://www.nws.noaa.gov/ops2/Surface/index.htm.

07/10 :  New Downloads?

   added 2 new new downloads, nothing really interesting, the SWO(7900) and the ASOS user guide

if you all can find anything else in electronic format we can use please end me a link/s