1 National HIC/RH/HQ Meeting ● January 27, 2006 version: 20011128 FOCUSFOCUS FOCUSFOCUS FOCUS FOCUSFOCUS FOCUSFOCUS FOCUSFOCUS FOCUSFOCUS FOCUSFOCUS FOCUSFOCUS

1National HIC/RH/HQ Meeting ● January 27, 2006version: 20011128

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New Snow Products from the National Operational Hydrologic

Remote Sensing Center

3National HIC/RH/HQ Meeting ● January 27, 2006

National Snow Analyses (NSA)

Ground

Airborne

Satellite

Multi-sensor Snow Observations

Data Products

Interactive Maps

Time Series Plots

Text Discussions

Snow Information Products

Snow Modeling and Data Assimilation

Numerical Weather Prediction Model

Forcings

Gridded Snow Characteristics

U.S.

1-km2

Hourly



Ground

Airborne

Satellite


• National Weather Service– First-order Stations– Cooperatives

• Federal and State Agencies– NRCS SNOTEL and Snow Courses– USACE New England District Snow Surveys– Federal Aviation Administration– California Dept. of Water Resources

• Regional Mesonets– Maine Cooperative Snow Survey– PA, OK, IA, ND, NC State Mesonets– MESOWEST (150 smaller mesonets)

• International Agencies– St. John River Basin– Environment Canada– BC Hydro

• National Weather Service– First-order Stations– Cooperatives

• Federal and State Agencies– NRCS SNOTEL and Snow Courses– USACE New England District Snow Surveys– Federal Aviation Administration– California Dept. of Water Resources

• Regional Mesonets– Maine Cooperative Snow Survey– PA, OK, IA, ND, NC State Mesonets– MESOWEST (150 smaller mesonets)

• International Agencies– St. John River Basin– Environment Canada– BC Hydro

50,000+ stations in database

25,000+ actively reporting stations

10,000+ unique stations reporting snow observations

50,000+ stations in database

25,000+ actively reporting stations

10,000+ unique stations reporting snow observations



Ground

Airborne

Satellite


• Snow Water Equivalent Measurement– Attenuation of natural terrestrial gamma

radiation by water in snow

• Snow Water Equivalent Measurement– Attenuation of natural terrestrial gamma

radiation by water in snow

NWS Airborne Snow Survey Program



Ground

Airborne

Satellite


2,187 Flight Lines

31 States, 8 Provinces

2,187 Flight Lines

31 States, 8 Provinces

Airborne Snow Survey Program Flight Line Network



Ground

Airborne

Satellite


Alaska Flight Line Network

191 Flight Lines



Ground

Airborne

Satellite


• Areal extent of snow cover is mapped using optical remote sensing data from geostationary and polar-orbiting satellites.

• Cloud cover obscures surface – significant problem.• Sub-pixel percentage of snow cover (FSCA)

developed by ERDC/CRREL is in second year of testing in NWS/NOHRSC operations.

• Areal extent of snow cover is mapped using optical remote sensing data from geostationary and polar-orbiting satellites.

• Cloud cover obscures surface – significant problem.• Sub-pixel percentage of snow cover (FSCA)

developed by ERDC/CRREL is in second year of testing in NWS/NOHRSC operations.

Feb 9 2004 - NOHRSC

Satellite Areal Extent of Snow Cover



Ground

Airborne

Satellite


Feb 9 2004 - NOHRSC

80%

80%

0%20%

20%

50%

50%

50%

Percent Snow Cover

100%

Advanced Very High Resolution Radiometer (AVHRR)

Fractional Snow Cover

1 km

1 km

1 km

1 km 1 km 1 km


AVHRR Fractional Snow Cover 2005 December 15



Ground

Airborne

Satellite


Data Products

Interactive Maps

Time Series Plots

Text Discussions




Forcings


U.S.

1-km2

Hourly


National Snow Analyses (NSA)• Land Surface Model for Snow and Soil

– Domain: Continental U.S.– Resolution: 1km2, Hourly – Physics: 5-Layer Energy and Mass Balance

• Spatial implementation of modified 1-D SNTHERM model developed by ERDC/CRREL (Anderson/Jordan)

• Spatial implementation of Prairie Blowing Snow Model (Pomeroy et al.)

– Forcing: Mesoscale Weather Analyses• RUC2, Eta physically downscaled to 1 km2

– Snow State Variables: • Water Equivalent (SWE)• Total Depth• Surface Temperature• Average Temperature• Liquid Water Content (Snow Wetness)• Snow Melt

• Snow Data Assimilation System– Multi-sensor data fusion to update snow

states in model (SWE, snow depth)

• Land Surface Model for Snow and Soil – Domain: Continental U.S.– Resolution: 1km2, Hourly – Physics: 5-Layer Energy and Mass Balance

• Spatial implementation of modified 1-D SNTHERM model developed by ERDC/CRREL (Anderson/Jordan)

• Spatial implementation of Prairie Blowing Snow Model (Pomeroy et al.)

– Forcing: Mesoscale Weather Analyses• RUC2, Eta physically downscaled to 1 km2

– Snow State Variables: • Water Equivalent (SWE)• Total Depth• Surface Temperature• Average Temperature• Liquid Water Content (Snow Wetness)• Snow Melt

• Snow Data Assimilation System– Multi-sensor data fusion to update snow

states in model (SWE, snow depth)



Forcings


U.S.

1-km2

Hourly


NOHRSC Model Physics


NSA ProductGeneration

Interactive MapsDigital DataDiscussions

NSA ProductGeneration

Interactive MapsDigital DataDiscussions

TemperatureRelative Humidity

Wind SpeedSolar Radiation

Atmos. RadiationPrecipitation

Precipitation Type

Hourly InputGridded Data (1 km)

Hourly InputGridded Data (1 km)

Soils PropertiesLand Use/Cover

Forest Properties

Static GriddedData (1 km)

Static GriddedData (1 km)

Snow Energy and Mass Balance Model

Snow Energy and Mass Balance Model

Blowing Snow ModelBlowing Snow Model

Radiative Transfer ModelRadiative Transfer Model

State Variables forMultiple Vertical

Snow & Soil LayersSnow Water Equivalent

Snow DepthSnow Temperature

Liquid Water ContentSnow Sublimation

Snow Melt

State Variables forMultiple Vertical

Snow & Soil LayersSnow Water Equivalent

Snow DepthSnow Temperature

Liquid Water ContentSnow Sublimation

Snow Melt

Snow Modeling Framework

1

1

Data Assimilation2

3

Snow Observations

Snow Water Equivalent

Snow Depth

Snow Cover

Snow Observations

Snow Water Equivalent

Snow Depth

Snow Cover


Over 25,000 Reporting Stations


Interactive Snow Information Systemwww.nohrsc.noaa.gov


Interactive Snow Information System

ModeledObserved

SWE

Density

Depth



Ground

Airborne

Satellite


Data Products

Interactive Maps

Time Series Plots

Text Discussions




Forcings


U.S.

1-km2

Hourly



High-resolution Daily and Hourly Gridded Snow Data Sets of Fused Model and Observations

• Snow Water Equivalent

• Snow Density

• Snow Sfc. Temperature

• Snow Avg. Temperature

• Snow Melt

• Sublimation

• Snow Wetness

Local Information (1 km2)

Continental U.S. Information

• Snow Depth

• Archived at NCDC, NSIDC, and NDFD (soon)

Data Products

Interactive Maps

Time Series Plots

Text Discussions



National Snow Analyses (NSA)Integrated Modeled / Observed Snowpack State Variables

Daily Basin-by-Basin SHEF Products Shipped to AWIPS

1. Snow Water Equivalent *

2. Snow Depth *

3. Areal Extent of Snow Cover *

4. Blowing Snow Sublimation

5. Surface Sublimation

6. Snowmelt

7. Average Snowpack Temperature

8. Rain plus Melt

* Includes assimilated snow observations


www.nohrsc.noaa.gov

Over 12 million hits per month




Physical Element Map Options


Examples of Observed Snow Products• NWS Cold Region Workshop: November 2004• No modeled snow information is contained in the

observed snow product maps.• Observed snow product maps include:

– Snow depth– Snow water equivalent– Total snowfall– Interpolated total snowfall

• Each product is generated for previous 24, 48, and 72 hour periods (i.e.,12 total).

• Each product is updated every 2 hours to include most recent snow observations.

• Associated alphanumeric data are posted to NOHRSC web site.


Interactive Snow Information System1-2-3 Day Snow Depth

Observations


Interactive Snow Information System1-2-3 Day Snow Water

Equivalent Observations


1-2-3 Day Snowfall Observations





• Interactive climatological information in SNOW-Info

– New capability added last year

• Two types of information

– Maps: Monthly Normal Snow Depth

• NCDC 1961-1990 Climate Atlas for U.S.

– October through April

– 4 km resolution

– Based on 5525 stations used in the NCDC U.S. Snow Climatology (TD-9641M)

– Stations: Daily Snow Depth Climatologies • NCDC TD3200 Cooperative Summary of the Day

– 4000 first-order and cooperative observer stations

– SNOW-Info database currently extends to 1970, eventually to 1948

New Climate Diagnostic Tools


Monthly Normal Snow Depth 1961-1990

New Climate Diagnostic Tools

OCT NOV DEC

JAN FEB MAR

APR

• SNOW-Info includes

– Monthly-normal maps

– Daily NSA departure-from-normal maps


New Climate Diagnostic Toolswww.nohrsc.noaa.gov

Snow Depth



Normal Snow Depth November (1961-

1990)



Daily Deviation from Monthly Normal Snow Depth November

(1961-1990)



Modeled and Observed SWE and Depth





Snow Water Equivalent Snow Depth

Snowpack Temperature Surface Sublimation


Snowpack Temperature

Snowmelt


10,000 Snow Reporting Stations

NOHRSC NSA Time

Series


Snow Reporting Station Metadata


Snow Reporting Station Metadata

Land Use / Land Cover

Forest Density


In Summary


Thank You !Thank You !www.nohrsc.noaa.gov

Documents

1 National HIC/RH/HQ Meeting ● January 27, 2006 version: 20011128 FOCUSFOCUS FOCUSFOCUS FOCUS FOCUSFOCUS FOCUSFOCUS FOCUSFOCUS FOCUSFOCUS FOCUSFOCUS FOCUSFOCUS