Cold Regions Hydrology Workshop

Breakout Session Description and Status

Use of SNODAS in NWSRFS

This was more of a general discussion on how the various RFCs are currently utilizing SNODAS. There is currently a broad spectrum of users at the RFCs. At least one RFC has been fairly aggressive in their use of SNODAS information and periodically does wholesale updates of the SWE states based on the current SNODAS states. At the other end of the spectrum is an office that has really not done very much at all with SNODAS. In the past, it has been viewed as experimental and they had sufficient local procedures that they did not investigate the use of SNODAS. However, they want to look into it more. More common is the middle ground where offices are comparing SNODAS output with SNOW-17 output and updating SNOW-17 as they feel appropriate.

There was some discussion on the ability to get NOHRSC products into AWIPS. Due to security restrictions, we are unable to view the NOHRSC web page directly from the AWIPS platform. This makes it somewhat more difficult to access the products. There was some discussion as to whether it would be possible to have either graphics or data made available for use on the AWIPS platform. Of particular interest were some of the basin-average time series plots. Another option that was discussed outside of the breakout session was to request that the security restrictions be relaxed so that some limited (i.e. specific sites) web browsing be permitted from AWIPS workstations.

More validation exercises are also needed on the use of SNODAS. The tests that were performed last winter in ER were somewhat flawed, but provided an initial start. Consideration should be given to designing a more comprehensive evaluation of SNODAS' impacts on hydrologic forecasts. One simple (but incomplete) test would be a simple comparison of the rain plus melt (RAIM) output of the SNOW-17 model compared to comparable output from SNODAS. This would require some minor changes in SNODAS code but could be accomplished fairly easily for this season.

There were no specific action items from this session.