A Simple and Inexpensive Method to Measure Snow Water Equivalent:

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A Simple and Inexpensive Method to Measure Snow
Water Equivalent

• Updates, Developments, and How the Data is Being
  Used

Andrea Holz Hydrologist North Central River
Forecast Center
James LaRosa Hydrology Program Manager National
Weather Service Marquette, MI
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Changes To The Snow Tube Design
gt The new design (left) does not have teeth cut
into the flared end of the pipe. Not sure why,
but I have found this allows more snow to get
into the pipe.
Does the snow escape out the side in between the
teeth?
Does the snow get stuck where the pipe constricts?
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How The Data Stacks Up
gt For the most part, the data collected by the
Adirondack and muffler pipe were similar. A high
bias could be argued for the muffler pipe as snow
often fell out of the Adirondack tube, especially
at low snow depths.
The difference in the data in the middle of the
chart is likely due to ice formation in the
snowpack. Snow can get caught up in the
bottle-neck area, and to combat this, observers
have been instructed to use the other end of the
pipe and apply a correction factor.
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Expansion Of The Empire
gt The network of weekly SWE observers has grown
to 24, most of which are water treatment plant
operators. Although a handful of spotters,
cooperative observers, and others with an
interest in snowmelt runoff were recently added
after outreach activities.
Additional SWE data is obtained from more than 50
NOHRSC Gamma Flight lines, and 26 supplemental
locations within the Menominee River Basin.
However, this data is not collected on a weekly
basis.
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Weekly Maps Of The Data
gt A typical weekly map of SWE data shows the
areas of concern, and point data taken by the
volunteer observers. A larger scale and more
colors are needed, plus the National Weather
Service logo.
Feedback from users, including County Emergency
Managers, Michigan Department of Environmental
Quality, engineering firms, and the users
themselves has been very positive.
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Other Local Uses For The Data
gt After the flooding of the Dead River due to a
levee failure in May 2003, there was a lot of
concern as to how much water would be flowing
into the Dead River Storage Basin.
Local users placed a map of the watershed
boundary on the SWE map, giving them a general
idea of how much water could potentially flow
into the system.
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SWE Observations Used in NWSRFS

• NCRFC has capability to look at point data and
  compare observed data with model simulated Mean
  Areal SWE.
• NCRFC can list observed SWE data in the SNOW-17
  Output for closer comparison.
• If more than one SWE observation is available in
  the basin, a WEIGH-TS operation can be used to
  create a Mean Areal SWE.
• Important for river forecasters to remember the
  observation is at one point in the basin.
• Observed SWE is useful when looking at
  accumulation and ablation trends.
• NCRFC uses NOHRSC model output as a Mean Areal
  SWE comparison tool.

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Compare SWE graphically
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SNOW-17 Output Listing
Watton SD SWE Observations
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NOHRSC Web Graphic
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NCRFC Use of Observations

• Weekly SWE observations aid in setting up SWE
  values for melt
• Weekly SWE observations aid in monitoring
  accumulation and ablation trends
• SWE observations aid NOHRSC in assimilating their
  model, which is used daily at NCRFC
• More observation points more confidence in snow
  model more consistent snow melt river forecasts