|Posted: Feb 25, 2009Post Subject: Huge data spikes
|Thanks to Paul Martzen for bringing to my attention that Kaweah - Inflow Terminus Res was reporting huge spikes (e.g. 128,000 cfs, or 262,000 cfs, or 2.5 million cfs).|
Dreamflows was downloading the relevant data from CDEC's TRM site, and as you can see if you click on the link and go back in time, every now and then it reports said ludicrous flow values.
Happily, an alternative data source exists, so Dreamflows is now accessing Army Corps of Engineers data instead. Yay! go ACOE! Hopefully, the problem will now go away and stay away. However, if you see similar problems with other flow sites reported by Dreamflows, please let me know. Thanks!
|The Army Corps data feed for Terminus Reservoir has spikes of its own, however. The reported flow on 2/27 for 5pm was 480 cfs, at 7pm was 5780 cfs, and at 8pm was 480 cfs.|
It's impossible for the actual flow to jump around like that - be certain the 5780 cfs entry is an artifact. In this case it's caused by a misreading of half an inch in the reservoir height, at 6pm. For more information on problems with computing reservoir inflow, see http://www.dreamflows.com/faqs.php#Q6
But if you see a very high flow you don't have to wonder if it's real for long. Just click through to the graph! If you see a sudden huge upward spike, be suspicious. If it comes down again an hour later, you'll know the high reading was bogus. If it stays up at a very high value, turn on the radio or teevee and listen for reports of massive flooding around the state. If such reports are missing, still be suspicious.