Big Hole River Drought Management Plan

From Mike Roberts, DRNC Hydrologist and Jacqueline Knutson, MFWP Hydrology Technician. As of 8/16/2017:

Streamflows:    We nearly made it all the way through July without hitting DMP or CCAA flow targets in Section I (Upper Big Hole). However, lack of precipitation and warm weather have led to river restriction above the North Fork confluence and we are flirting with or below flow targets at multiple sites now. Cooler nighttime temperatures have contributed to the lifting of Hoot Owl restrictions in the Upper Big Hole this week. Upper basin streamflow contributions from CCAA landowners began in the last few weeks and enrolled landowners are complying with site plans. Sections II, III, and IV are maintaining flows and remain above DMP action levels. Streamflows in Section V reached 150 cfs today which is at the conservation level (phone tree etc.).

Precipitation:    Precipitation in Montana was below average for July due to a high pressure ridge that centered over the state early in the month. The first half of the month saw some thunderstorm activity but very little sustained precipitation. During the second half of July thunderstorms became more infrequent and conditions became drier creating severe fire activity that has continued to bring smokey conditions to the Big Hole Valley. Valley rainfall amounts in both the upper and lower Big Hole totaled a half inch or less for July (less than half the average).  The high pressure ridge that dominated Montana in July began to break down in early August and thunderstorms and cooler weather have begun to return.

Temperatures:   July temperatures were above normal across the state. Montana recorded its 4^th warmest July of record (138 years) and the warmest since 2007. This was due, in part, to the same high pressure ridge that settled over Montana and chased away the rain.   

Forecast:   Forecasters are increasingly coming to the conclusion that this winter will be ENSO-neutral meaning that there will neither be a La Nina nor El Nino event. While forecasters are confident in neutral ENSO conditions through February of 2018 this makes it very difficult for forecasters to be confident of anything else. There are plenty of other patterns influencing weather conditions but without a clear El Nino or La Nina event it is very difficult for forecasters to make predictions months in advance.

For the next three months, though, we can expect a continuation of above average temperatures in Southwest Montana. Precipitation is proving more difficult to forecast but we will likely see average fall precipitation through October.

These forecasts are always subject to change.  (http://www.cpc.ncep.noaa.gov/products/predictions/30day/).