David J. Gochis, Scientist, National Center for Atmospheric Research - September 2016 UCAR Congressional Briefing WRF-Hydro, a powerful NCAR-based computer model developed by a collaborative community drawing from academia, federal labs, and private industry, is the first nationwide operational system to provide continuous predictions of water levels and potential flooding in rivers and streams from coast to coast. NOAA's new Office of Water Prediction selected it last year as the core of the agency's new National Water Model. WRF-Hydro is designed to provide adaptable modeling for assimilation and prediction of precipitation, soil moisture, snowpack, groundwater, streamflow, and inundation.

1. September 13, 2016
David J. Gochis
Scientist
National Center for Atmospheric Research
Boulder, Colorado
!
Large!integrated!NOAA/OWP,!NCAR!team!and!CUAHSI!team!
OWP
Office(of
Water
Prediction
The Community WRF-Hydro and
its Implementation as the NOAA
National Water Model

2. The Community WRF-Hydro Modeling System
NOAA National Water Model using WRF-Hydro
WRF$Hydro*$*A*community$based,*supported*water*modeling*system*designed*to*
provide:*
1. Adaptable!modeling!system!for!assimila&on)&)predic&on!of!precipitaCon,!soil!
moisture,!snowpack,!groundwater,!streamflow,!inundaCon!
2. ‘Accurate’!and!‘reliable’!streamflow!predicCon!across!scales!from!hillslopes!to!
larger!river!basins!
Water&Informa,on&Across&Scales&

3. National Water Model Technical Details:
NOAA National Water Model using WRF-Hydro
Data*Throughput:*
• Input!data!per!day:!!4.45!Terabytes!
• Output!data!per!day:!3!Terabytes!
• #!of!river!channels:!2.7!million!
• #!of!reservoirs:!1,260!
• Total!#!of!computaConal!elements:!
~360,000,000!
Model*Details:*
• Number!of!lines!of!code:!74,740!
• Computer!usage:!>!100,000!cpuX
hours!per!day!
AssimilaAon*of*real$Ame*streamflow:*
• ~8,000!USGS!stream!gauges!!
NaAonal*Streamflow*Anomaly*Map*
Available*online*at:)h1p://water.noaa.gov/tools/nwm9image9viewer)

4. Configuration of the National Water Model
GOAL:**NaAonal*coverage*at*‘hyper$resoluAon’…..i.e.*‘neighborhood$level’*detail*
National Water Model
Version 1.0: Model Chain
USGS&gauge&
assimila,on&

5. National Water Model Output Data:
NOAA National Water Model using WRF-Hydro
NaAonal*Soil*Moisture*Forecasts:*

6. National Water Model Output Data:
NOAA National Water Model using WRF-Hydro
NaAonal*Plant*Water*Use*and*EvaporaAon*Forecasts:*

7. National Water Model Output Data:
NOAA National Water Model using WRF-Hydro
NaAonal*Snowpack*Forecasts:*

8. National Water Model Output Data:
NOAA National Water Model using WRF-Hydro
NaAonal*Surface*Water*InundaAon*Forecasts:*

9. National Water Model Output Data:
NOAA National Water Model using WRF-Hydro
NaAonal*Soil*SaturaAon/Shallow*Groundwater*Forecasts:*

10. Seamless!SimulaCon!of!NaCon’s!Hydrologic!System!

11. National Water Model Output Data:
NOAA National Water Model using WRF-Hydro
• Forecasts!from!Short,!Medium!and!
Long!Range!configuraCon!
• Uncertainty!informaCon!from!
mulCple!model!cycles!
Local*streamflow*forecasts*at*2.7M*river*channels:*

12. Case!Study:!!
Hurricane!Joaquin!
Landfall,!
CarolinasX2015*

13. Case Study: Houston Flooding - 2015
NOAA National Water Model using WRF-Hydro
• Next!chapter!of!NWS!‘ModernizaCon!of!Hydrologic!Monitoring!and!PredicCon!
Services’!
Move*from*~4,000*forecast*points!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!to!over*2.7*million*river*reaches*
Image*Courtesy**
Fernando*Salas*(NWC)*

14. The journey is just beginning….Major Challenges Ahead
NOAA National Water Model using WRF-Hydro
Water!in!the!‘Anthropocene’:*
!
• Water!control!
• Landscape!change!
• Climate!change!
!

15. Parting Thoughts:
NOAA National Water Model using WRF-Hydro
Community*Engagement:*
– Move!from!Building!Models…to!Building!CommuniCes!
• ProducCve!communiCes!are!build!through!sharing!of!
perspecCves!and!resources!
• Engaging!scienCsts,!pracCConers!and!decision!makers!to!solve!
realXworld!problems!
– Build!a!beeer!observaConal!network!
– Revolu&onize)public)access)to)water)intelligence)