climate prediction applications science workshop national weather service 1 climate prediction...

Climate Prediction Applications Science Workshop National Weather Service

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Climate Prediction Climate Prediction

Applications Science WorkshopApplications Science Workshop

Jim NoelJim NoelSenior HydrologistSenior Hydrologist

NOAA/ National Weather ServiceNOAA/ National Weather ServiceOhio River Forecast CenterOhio River Forecast Center

March 4, 2008March 4, 2008


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OutlineOutline

• History of Flood Outlooks

• Why change now?

• Ensemble Streamflow Prediction (ESP)

• Climate Forecasts within ESP

• Experimental Water Resources Outlooks

• Expansion of Climate Products – Examples

• Summary


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HistoryHistory

• Based on series of text products

• Subjective in nature

• Only produced in flood season

• Not a continuous water watch for high and low flows

From Hydrologic Information Center – April 14, 2006


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Why Change Now?Why Change Now?

• Need for continuous water watch

• Need to collaborate with our partners more

• Technology advances allow us to provide more useful information

• Innovate or dissipate


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Ensemble Streamflow PredictionEnsemble Streamflow Prediction

• River Forecast Centers capture soil moisture using SAC-SMA (Sacramento) hydrologic soil moisture accounting model and capture snow using SNOW-17 model

• Good estimations of soil moisture and snow pack water contents are critical to accurate hydrology (RFCs) and meteorology and climate (NCEP) forecasts.

• To get good soil moisture estimations requires good precipitation inputs


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MCP

OFS ESP

Manual Calibration Program (MCP) Manual Calibration Program (MCP)

Operational Forecast System (OFS)Operational Forecast System (OFS)

Ensemble Streamflow Prediction (ESP)Ensemble Streamflow Prediction (ESP)



7 Advanced Hydrologic Prediction Service

Ensemble Streamflow Prediction Ensemble Streamflow Prediction

RFC NWSRFS/ESP/Probabilistic

• Ensemble Streamflow Prediction (ESP) necessary component used to take short range deterministic SAC-SMA model into short term climate predictions of rivers

• Similar in concept to the ensembling approach used for atmospheric modeling


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Results used in statistical analysis to produce forecasts with probabilistic values

Multiple streamflow scenarios with historic meteorological or forecast weather/climatic data

Time

Flo

w

Scenario 1

Saved model states reflect current

conditions

Possible scenarios

Scenario 2

Scenario 3

©The COMET Program



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Flo

w

Time

Future

Now

Past

Low chance of this level flow or higher

High chance of this level flow or higher

Medium chance of this level flow or higher

©The COMET Program



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Pre Adjustment Technique Weight/Modify on Input Side

7172737475

Post Adjustment TechniqueWeight On Output Side

Climate Forecasts Within ESPClimate Forecasts Within ESP


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Climate ForecastsWeather Forecasts

HistoricalMAT and MAP

AdjustmentSystem

Adjusted HistoricalMAP and MAT

Climate Forecasts Within ESP Climate Forecasts Within ESP


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Long range seasonal water supplyLong range seasonal water supply

Spring snowmelt volume forecastsSpring snowmelt volume forecasts

Spring snowmelt peaksSpring snowmelt peaks

Minimum flows for navigation, irrigation, Minimum flows for navigation, irrigation, environmental, recreation, etcenvironmental, recreation, etc

Water Resources OutlooksWater Resources Outlooks

Climate Forecasts Within ESP Climate Forecasts Within ESP


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Climate Forecasts within ESPClimate Forecasts within ESP

• 90-day probability of exceedance

• Blue line is an historical simulation based on climatology

• Black line is the conditional simulation with CPC inputs

• Conditional simulation based on CPC inputs yield lower potential for flooding and high flows.


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• Water Resources Outlook

• Uses NWSRFS SAC-SMA and ESP

• Uses HPC/CPC Outlooks

• Can generate a whole host of products

• An experimental product of NOAA/NWS

• Being develop for the 30 to 90 day period


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• Partner with USGS/USACE

• Utilize USGS streamflow percentiles

• Verify product based onUSGS 28-day mean flows

• Experimental has ended, waiting for operational approval

• GOAL: Slowly expand nationwide


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• Based on basins and point forecasts

• 159 of 266 OHRFC points have 30, 60 and 90 day expected streamflows

• 20 more USGS points could be used but incomplete data


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30-day Verification

August 2006 through January 2008

• POD above normal flows = 0.78

• FAR above normal flows = 0.30

• POD below normal flows = 0.65

• FAR below normal flows = 0.09

• Percent of forecast basins in correct category = 78%


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Water Resources OutlookWater Resources Outlook

Other ApproachesOther Approaches

• Use analog years (year weighting technique in ESP (Post-Adjustment) based on atmospheric and oceanic response (ENSO/NAO etc)

• Run ESP with CPC outlooks and analog years approach

• Research on this is being done by OHRFC and hopefully Michigan Tech


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Expansion of Climate Products - ExamplesExpansion of Climate Products - Examples

• Probability of reaching flood stage

• Uses NWSRFS SAC-SMA and ESP

• Generated at NCRFC for minor, moderate and major flooding

• An experimental product of NOAA/NWS

• Being expanded at other RFCs


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Expansion of Climate Products - ExamplesExpansion of Climate Products - Examples

• Link WRO for each of our points to probability function images

• Allow customers to drill down into the WRO further

• Allow customers to modify risks based on ENSO as a starting point

• This work is being driven by NWS Western Region


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SummarySummary

• Technology (ESP) has advanced to allow subjective text based flood outlooks to be replaced by a more objective based water resources outlook

• Climate forecasts are integrated into hydrologic forecasts mostly through adjustments to the inputs in the Ensemble Streamflow Prediction

• Water Resources Outlooks would provide a continuous water watch for streamflows in the 1-90 day period for expected flows

• Water Resources Outlooks would not only be for high flows but ALL flows


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SummarySummary

• Streamflow categories are based on USGS percentile categories

• Verification is based on USGS data

• Designed to promote NWS/USGS/COE and help us and other partners and customers in their missions!

•The climate products can be used in providing necessary information on flood and drought potential during the coming months.

climate prediction applications science workshop national weather service 1 climate prediction...

Documents

esp slide

mat climate forecasts

climate ncep forecasts

nationwide slide

day period slide

incomplete data slide

atmospheric modeling

continuous water watch