Annual Precipitation Relationship to Elevation

The following seven weather stations align along a SW-NE profile. Their elevations and average annual precipitations were plotted and the results (except Galena) fitted with an exponential curve. The locations, elevations, and precipitation data for these stations were obtained from the extensive compilations at the Western Regional Climate Center. Exceptions to WRCC's data are noted in the discussion below.

ID Station Type Elev. Precip.   Record Lat. Long. Inc. Precip.
A Mt. Rose Ski Snotel 8801 54.24   1981 - 2016 N 39 18' 56" W 119 53' 41"  
B Mt. Rose Bowl Coop 7507 30.60   1973 - 1987 N 39 20' 21" W 119 52' 24"  
C Mt Rose / Xmas Coop 7120 23.85   1968 - 2016 N 39 20' 32" W 119 51' 49"  
D Galena RAWS 5830 Inc.   2002 - 2016 N 39 22' 46" W 119 49' 54" 11.20
E TCE Priv 4984 9.60   2000 - 2016 N 39 24' 56" W 119 47' 41"  
F Wolf Run DRI 4880 8.81   2000 - 2016 N 39 24' 17" W 119 46' 41"  
G Reno Airport NWS 4403 7.22   1937 - 2016 N 39 30' 27" W 119 46' 05"  

Map of SW-NE Precipitation Profile

Average Annual Precipitation Relationship to Elevation

Except for the Wolf Run and Galena stations, all the others are/were either Snotel, Coop, or heated stations. Non-heated stations can not accurately measure the water equivalents of heavy snows due to overloading of the catchment volume of their rain gauge and the subsequent sloughing loss of the overstacked snow off the gauge. So the Wolf Run station under reports its precipitation results to some degree after a heavy snow storm. The Galena RAWS station could be another station on this profile with a corrected elevation of 5830 feet; however, it is also unheated and therefore can under report snow storm precipitation totals. It also tends to have data loss during and after significant snow storms. It's precipitation data is considered incomplete and is shown as a blue square on the plot.

The location for the Mt. Rose Bowl Coop station was approximated to be consistant with the published elevation and to be near Sky Tavern which has the exact same published location and elevation. The rain gauge and instruments for Coop stations require easy access for the observers to make daily readings. The published location for Mt. Rose Bowl is in a difficult to access, remote valley at a much lower elevation (6700') and therefore cannot be correct.

The published elevation for Mt. Rose Christmas Tree is wrong. The location was established by comparison to site photos and the correct elevation was then determined from the topographic map. The average annual precipitation was obtained from NWS data tables.

To correct the locations and elevations of these stations, the powerful mapping web site, ACME Mapper 2.1 has been used extensively.

It is unclear if the elevation is the sole controlling factor for the amount of precipitation on this profile, or if the perpendicular distance east from the mountain crest is involved, or if it is a mix of both factors.

A detailed monthly cross comparison of the Wolf Run precipitation results with those of the TCE station was conducted for the last eight years of data (2008 - 2016). The results indicate that the total Wolf Run station precipitation for that period was about 12% lower than at the TCE station. As much as 5% of that difference can be attributed to its lower elevation. The 7% remaining difference is due primarily to the frequent failure of the Wolf Run station to record data during winter rain storms. 10% of the 100 months checked had data losses occurring on rain days that significantly reduced (more than 0.33 inch) the monthly precipitation results.

Exceptional Winter Storms of October, 2016 through March, 2017

The usually high precipitations for the winter of 2016 - 2017 were plotted and curve fitted for Mt. Rose Ski Snotel, Mt. Rose Christmas Tree Coop, and the Reno Airport as shown on the graph below The exponential equation is listed on the graph. The precipitation amounts for TCE and Wolf Run are also plotted on the graph, but were not used in the curve fit because they appear to be anomalously high compared to the exponential equation.

Average annual precipitation compared to that through the water year months of Oct,'16 - Mar,'17

This deviation is thought to be proof of the Mt. Rose Summit Precipitation Plume. This anomalous precipitation plume is believed to be caused by reduced rain shadowing as moisture-laden air passes through the lower elevation gap between Mt. Rose and Slide Mountain during atmospheric river storms with northeasterly prevailing winds.