Weather forecasting for the eastern slope of the Sierra Nevada and Truckee Meadows is often a difficult task. With the deployment of WSR-88D technology and improvements in mesoscale modeling, the forecaster's skill will improve. A cornerstone for the use and evaluation of these new tools is a surface network of hydrometeorological observing sites. Such a network must be of high quality and sufficient density to match the resolution of the 88D and the grid spacing of numerical models.
There are a number of meteorological data networks in the Truckee Meadows and surrounding area that are operated by various federal, state, and local agencies. The purpose of this project was to integrate the data from these networks into a single database. This integrated database will improve local forecasting and warning by its use in three broad areas: 1) a real-time, high quality, high density data source for improved knowledge of hydrometeorological variables at ground level which forecasters can use to check model predictions; 2) inputs to mesoscale models and verification of model results; and 3) ground truth for 88D quantitative precipitation forecasts.
Each of the hydromet networks was identified and their characteristics cataloged in 1994. Data are currently being acquired from 128 sites with a total of 399 sensors. A searchable database of the sensors was created for use of the data via a remote access system. The hydromet data from these networks are automatically collected at the NWS office and transmitted every 30 minutes to the Western Region Climate Center where they are permanently archived.
In addition to developing this mesonet, a second objective was to develop a
graphics product that would enable forecasters to see up-to-date meteorological
information mapped over well-known features, such as political boundaries and
rivers. The graphics package chosen for this is the GRADS package which not
only had the capability to overlay weather data and information on map layers,
but also had the native ability to produce standard meteorological diagrams.
The GRADS image is converted to a GIF image which is accessed by NWS forecasters
by clicking on an icon using a standard web browser. Maps are produced for 30
minute intervals, updated every 60 minutes. A sequence of the 12 most recent
maps is stored for retrospective viewing and can be viewed in a looping manner.
This graphic display of the mesonet in real-time has proven to be extremely
useful to the forecasters in picking out mesoscale features, which translates
into producing better short-term
forecasts.