The NWS National Operational Hydrologic Remote Sensing Center (NOHRSC) in Minneapolis is now producing several new products for WY2005 that we post to our web site (www.nohrsc.noaa.gov) and send to AWIPS. The following is a summary of the new daily NOHRSC products that are now available.

1. Deviation from Normal Snow Depth Maps

We have implemented a daily deviation from normal (1961-1990) snow depth map for the CONUS using monthly normal gridded snow depth products from NCDC. Both the NCDC monthly normal snow depth map and the daily NOHRSC deviation from normal snow depth maps are available from the physical element pull-down menu on the NOHRSC interactive snow information page (see section 5.3.1 in the NOHRSC Overview (pdf) or in the NOHRSC Overview on the NOHRSC homepage side-bar menu).

2. Historic Time Series of Daily Snow Depth Observations

Historic time series (1960 to present) of daily snow depth observations for over 5,000 reporting stations are plotted along with current observed and modeled NOHRSC snow water equivalent and snow depth information (see section 5.4.1.5 in the NOHRSC Overview (pdf) or in the NOHRSC Overview on the NOHRSC homepage side-bar menu).

3. Observed Snow Water Equivalent and Snow Depth Value Maps

We are now plotting the numeric value of snow water equivalent and snow depth observations on our interactive maps. The observed value maps are available from the physical element pull-down menu on the interactive snow information page (see section 5.3.2 in the NOHRSC Overview (pdf) or in the NOHRSC Overview on the NOHRSC homepage side-bar menu).

4. New Modeled Snowpack State-Variable Products in SHEF

In the past, the NOHRSC has distributed over AWIPS, in SHEF, modeled snow water equivalent (SWIPZ) and areal extent of snow cover (SAIPZ) products on a basin-by-basin basis. Beginning in mid-December, the NOHRSC will send to AWIPS the following modeled snowpack state-variable products in SHEF, for the CONUS, on a basin-by-basin basis:

• 1. Snowpack Thickness
• 2. Blowing Snow Sublimation Rate
• 3. Snowmelt Rate
• 4. Snowpack Average Temperature
• 5. Snowpack Sublimation Rate, and
• 6. Rain plus Melt

5. Recommendations for Making Snow Observations

The NOHRSC ingests snow information from over 10,000 snow reporting station across the CONUS and southern Canada. Additionally, we ingest hydrometeorological data from more than 25,000 reporting stations across the country. These observations are used in the NOHRSC snow modeling and data assimilation processes used to produce the National Snow Analyses (NSA) that we post daily to our web site (www.nohrsc.noaa.gov). We were recently asked for recommendations to be used by NWS field offices and other cooperative observers when taking snow observations to maximize their quality and benefit for a wide variety of NWS and non-NWS users including the NOHRSC.

Two critical recommendations are:

• 1. Snow water equivalent should NEVER be estimated from tables or by dividing snow depth by 10 (see NWS Manual 10-1311), and
• 2. Snow depth measurements should always be made and reported at the same time snow water equivalent measurements are made (see NWS Manual 10-1311 and Federal Meteorology Handbook No. 1).

6. NOHRSC Two-Page Summary Fact Sheet

NOHRSC prepared a two-page summary fact sheet (pdf) of the various NOHRSC operations and products. The fact sheet provides graphics of a few NOHRSC products and discusses the various formats used to distribute the National Snow Analyses (NSA) information. The fact sheet can be printed out on a color printer to generate a two-page NOHRSC handout. The fact sheet is also posted to the NOHRSC Technology page under the Public Presentations section.

If you have any questions, comments, suggestions for improvement, or simply require additional information, contact Tom.Carroll@noaa.gov