Thursday, 13 January 2005: 1:30 PM
Tracking NWS Area Forecast Discussions to Study the Subjective use of Wind and Temperature Profiler Data
The National Weather Service (NWS) forecasters use many different products when preparing their forecasts, including surface and aircraft observations, balloon soundings, satellite images, profilers, and numerical model guidance. We have been studying how the NWS forecasters utilize wind profiler data in their decision-making process. For this study, we focused on two general types of wind profilers: the NPN and the non-NOAA Cooperative Agency Profilers (CAPs). The NPN profilers measure clear-air signals within the troposphere and the lower stratosphere, and the CAP profilers typically measure signals only in the lower troposphere. Many of the profilers also measure temperature profiles. The Forecast Systems Laboratory (FSL) operates the NPN sites in cooperation with the NWS, and provides access to real-time data from all NPN sites and many CAP sites to the NWS and other worldwide users.
To complete this study, we used an automatic search program to monitor the NWS Area Forecast Discussions (AFDs) to help us gain a better understanding of the geographical distribution of the data being used, and how often and in what ways the NPN and CAP profiler data have been subjectively used at the NWS forecast offices. Each individual NWS forecast office typically writes two AFDs each day to describe current forecasting issues, both for the short-term and longer-term forecast periods. These AFDs are generally technical in detail and represent a “thought process” to be shared among forecasters within a single forecast office between shifts, and with adjacent NWS forecast offices.
At the conference, we will present the results of this year-long study, from 6 January 2003 to 5 January 2004. We will provide statistics on the number of times NPN and CAP data were used (or mentioned in AFDs), and will discuss the many ways in which the data were used in weather forecasting.