In early May 2014, MW&A published a prototype forecast of a ten-year-trailing-average (tyta) flow range applied specifically to the end of the calendar year for the Otowi gage of the Rio Grande in Northern New Mexico. Given typical winter patterns for this gage, it is not too early to propose that the forecast was a success.
A final evaluation of the forecast will be published in early 2015, when the USGS updates its monthly statistics for that gage. However, their preliminary daily values can be used, along with the historical seasonal patterns that are well known, to give confidence to a successful score for this first published forecast.
The first figure is an update of the original MW&A forecast graphic that was published on May 4. The final Otowi gage tyta flow value for calendar year 2014 will fall within the central region of the MW&A forecast range. Moreover, the relative difference between the MW&A forecast mean value and the anticipated flow value will likely be less than 3% by the final accounting. Arguably, we hit the bull’s eye, although in this graphical example, the edge was grazed.
Additional complementary forecast products were made on two occasions this year by MW&A. One product utilized our stochastic landscape calculations in June 2014 to estimate net flow past the Otowi gage for the calendar year. That estimate of ~700,000 af (acre feet) is expected to be within 10% of the final value.
The last product was published in September for subscribers only, and covered additional streams, including sections along the Navajo, Pecos, and Gila rivers and other Rio Grande tributaries.
We will follow up soon with a new forecast for the tyta value at Otowi gage for the end of 2015. One signature difference between our method and that of conventional approaches is that our process does not typically require spatial estimation of snowpack components for the year in which the forecast applies. Therefore, typically there is no need to wait until the Spring for our basic forecast to be published.
MW&A is pleased to present these positive results for our very first published forecast. With the support of an informed clientele, along with our new collaboration with LANL atmospheric scientist Dr. Petr Chylek, our ongoing continual process improvement is anticipated to enhance and accelerate our forecasting performance record for 2015 and beyond.