Wednesday, February 6, 2013

US NRCS February Snow & Water Report

The US Natural Resources Conservation Service released the February "Basin Outlook Report" for Idaho today.

Here's is what the NRCS experts have to say about The Salmon River watershed's snowpack:

Water supplies in the Salmon Basin remain promising despite January being drier than normal. Basinwide January precipitation was 73% of average, making it the first month this water year with less than average amounts. Monthly precipitation totals ranged widely across the basin. 

For example Mountain Meadows SNOTEL near the northern divide with the Clearwater basin, recorded 126% of normal precipitation for the month (5.9 inches), while Banner Summit SNOTEL near the southern divide with the Payette basin measured 49% of normal in January (2.7 inches). Water year to date precipitation since the beginning of October is above average, but dropped about 13 percentage points in the last month. 

The split in snowpack percentages between high and low elevations is still present, but less than last month. As of February 1, SNOTEL sites above 6,500 feet measured 107% of normal snow, while those below 6,500 feet had 90% of normal snow; last month the split was 123% to 80%. Overall the Salmon basin snowpack is near normal based on the 1981-2010 medians. 

Streamflow forecasts call for 114% of average flow this summer for the MF Salmon, while the SF Salmon and mainstem Salmon are closer to average. The lowest forecast is for the Lemhi River at 88% of average. January’s drier than normal weather dropped forecasts about 10-15% in one month. Let’s hope the slide does not continue through February.

Below is the full statewide report.  You can read this document online or download the report to view on your computer.

The report is also available from the US NRCS server at:
ftp://ftp-fc.sc.egov.usda.gov/ID/snow/watersupply/bor/2013/borid213.pdf


Here are some additional excellent links from the US NRCS
Snow graphs: http://www.id.nrcs.usda.gov/snow/data/basin_graphs.html
Flow http://www.id.nrcs.usda.gov/snow/watersupply/peakflow.html#salmon 
Data: http://www.wcc.nrcs.usda.gov/snow/
Flow Forecasts: http://www.id.nrcs.usda.gov/snow/watersupply/daily_guidance.html#Salmon

Many Thanks to US NRCS Snow Survey Water Supply Specialist Ron Abramovich for providing this information today.

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