U f W th d Cli t F tU f W th d Cli t F tUse of Weather and Climate Forecast Use of Weather and Climate Forecast Information in the CaliforniaInformation in the California--Nevada Nevada

River Forecast CenterRiver Forecast Center

Rob HartmanRob HartmanHydrologist in ChargeHydrologist in ChargeHydrologist in ChargeHydrologist in Charge

NWS / CaliforniaNWS / California--Nevada River Forecast CenterNevada River Forecast Center

Mission of NWS Mission of NWS Hydrologic Services ProgramHydrologic Services Program

•• Provide river and flood forecasts and warnings Provide river and flood forecasts and warnings for the protection of lives and propertyfor the protection of lives and propertyfor the protection of lives and property.for the protection of lives and property.

Provide basic hydrologic forecast information forProvide basic hydrologic forecast information for•• Provide basic hydrologic forecast information for Provide basic hydrologic forecast information for the nation’s environmental and economic the nation’s environmental and economic well being.well being.gg

NWS River Forecast CentersNWS River Forecast CentersNWS River Forecast CentersNWS River Forecast Centers

CNRFCCNRFC•• 245,000 sq. miles245,000 sq. miles•• 182+ modeled basins182+ modeled basins•• 80+ flood forecast points80+ flood forecast points•• 42+ reservoir inflows42+ reservoir inflows•• 50 water supply points50 water supply pointspp y ppp y p•• Lots of people!Lots of people!

CNRFC HydrologicCNRFC HydrologicProducts and ServicesProducts and Services

Local Flood Warning Systems Support

Short Range … … … … … … Long Range

Local Flood Warning Systems Support

Flash Flood Guidance

Headwater Guidance

Flood Forecast Guidance

Reservoir Inflow Forecasts

Spring Snow Melt Forecasts

Water Supply Volume

CNRFC HydrologicCNRFC Hydrologic ModelingModelingCNRFC Hydrologic CNRFC Hydrologic ModelingModeling

NWSRFS OFS

Short Range … … … … … … Long Range

NWSRFS – OFS6 hour time step, 5 day duration

modular, deterministic

NWSRFS - ESP………………...

Statistical

6 hour time step, ~ 1 year duration, ensemble-based, probablistic

simple, efficient, inflexibleseasonal duration

Operational Flood ForecastingOperational Flood ForecastingOperational Flood ForecastingOperational Flood Forecasting

Hydrologist

model

Hydrologist

hydrologicexpertise &

f tH River

guidanceexpertise &judgment

b ll tiFlood Forecast

forecastprecip / temp

AS

ForecastSystem

bulletinsgraphics Guidance

parameters

Observing

data

CalibrationgSystems

Calibration

Operational HAS FunctionOperational HAS FunctionOperational HAS FunctionOperational HAS Function

NWS Weather NCEP HydrometeorologicalNWS Weather Forecast Offices (11)

NCEP HydrometeorologicalPrediction Center

3-Day ForecastsU d t d 6 h

Local collaborationi d

AtmosphericModels

Updated every 6 hoursas required

LocalModels

5-Day Forecasts(6 hour interval )

- Precipitation

HAS - Temperature

- Snow LevelSurfaceObservations

S

RemotelySensed Data

Day 1 QPF Error (Feb05)Day 1 QPF Error (Feb05)Day 1 QPF Error (Feb05)Day 1 QPF Error (Feb05)

Day 2 QPF Error (Feb05)Day 2 QPF Error (Feb05)Day 2 QPF Error (Feb05)Day 2 QPF Error (Feb05)

Day 3 QPF Error (Feb05)Day 3 QPF Error (Feb05)Day 3 QPF Error (Feb05)Day 3 QPF Error (Feb05)

Rhea Orographic Aid (Days 4Rhea Orographic Aid (Days 4--6)6)Rhea Orographic Aid (Days 4Rhea Orographic Aid (Days 4 6)6)

•• Objective toolObjective tooljj

•• Outputs 6Outputs 6--hour orographic QPFhour orographic QPF

•• Input Input -- NCEP gridded datasets NCEP gridded datasets from AWIPSfrom AWIPS

Eta and GFSEta and GFSS l t t •• Eta and GFSEta and GFS•• Performed well during largePerformed well during large--

scale rain events in California scale rain events in California (1986 1997)(1986 1997)

Sample output...

==< SHASTA ABOVE SHASTA DAM - SHDC1

>==================================== STRDA BEG-END QPF SLVL FRZGLVL 700DIR

6 19 16-22 .00 35 5.1 253-299 WIND&RH WK SSE-NNW PRDIF12 19 22- 4 .04 28 4.3 299-257 WIND&RH WK SSE-NNW PRDIF (1986, 1997)(1986, 1997)

•• Mesoscale resolutionMesoscale resolution

18 20 4-10 .13 26 4.1 257-228 RH ONLY NORMAL PGRAD 24 20 10-16 .17 27 4.3 228-210 RH ONLY NORMAL PGRAD 30 20 16-22 .09 28 4.4 210-109 WIND&RH WK SSE-NNW PRDIF36 20 22- 4 .00* 30 4.6 109- 49 WIND&RH WK SSE-NNW PRDIFMODIFIED TOTS 04-04 .38 MOD-FAC = .85 * = 700mbWD >344 or <155 DEG42 21 4-10 .00* 38 5.4 49- 15 WIND&RH WK SSE-NNW PRDIF48 21 10-16 .00* 51 6.6 15- 14 WIND&RH WK SSE-NNW PRDIF54 21 16-22 .00* 57 7.3 14- 7 WIND&RH WK SSE-NNW PRDIF60 21 22- 4 .00 56 7.1 7-303 WIND&RH WK SSE-NNW PRDIFMODIFIED TOTS 04-04 .00 MOD-FAC = .85 * = 700mbWD >344 or <155 DEG

Rhea Orographic Aid PerformanceRhea Orographic Aid PerformanceNew Year’s Flood 1997 New Year’s Flood 1997 –– Feather River BasinFeather River Basin

The melting level strongly influences runoff I t i t h d

CNRFC River Forecasting SystemThe sensitivity of watershed

runoff to changes in melting levelfor a given 24-h QPF

In mountainous watersheds

70

80

9691

98100

for a given 24-h QPF

24-h QPF:0-6 h = 0.5 in6-12 h = 1.5 in12-18 h = 1.5 in

50

60

cfs

x 10

-3)

Klamath RiverSmith RiverTrinity RiverTruckee River

89

71

18-24 h = 0.5 in

30

40

Peak

flow

rate

(c

71 98 100

43 Percentage of river basinRiver/BasinRiver/Basin Area (miArea (mi22)) Precip. (in)Precip. (in)

10

20

P

735

74

16

43

1659

8796 100

Percentage of river basinbelow this altitude

(( )) p ( )p ( )

KlamathKlamath 772772 7070

SmithSmith 614614 103103

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000Melting level (ft)

0 21

16

White et al., JTech, 2002

TrinityTrinity 650650 6363

TruckeeTruckee 204204 4141

RainRain--Snow Elevation ForecastsSnow Elevation ForecastsRainRain Snow Elevation ForecastsSnow Elevation Forecasts

Flood Forecast GuidanceFlood Forecast GuidanceFlood Forecast GuidanceFlood Forecast Guidance

Ensemble ChallengesEnsemble ChallengesEnsemble ChallengesEnsemble Challenges

•• Maintain coherence between deterministic andMaintain coherence between deterministic andMaintain coherence between deterministic and Maintain coherence between deterministic and ensemble forecastsensemble forecasts

55--Day Ensemble PrototypeDay Ensemble Prototype55 Day Ensemble PrototypeDay Ensemble Prototype

St tSt t•• Status:Status:•• Several RFCs collaborating with OHD on shortSeveral RFCs collaborating with OHD on short--term prototypeterm prototype

Forecast TemperatureEnsembles

Probablistic Reservoir Inflow

Forecast PrecipitationE blEnsembles

ESP Use ofESP Use ofESP Use of ESP Use of Weather and Climate ForecastsWeather and Climate Forecasts

HistoricalMAT d MAP

AdjustmentS t

Adjusted HistoricalMAP d MATMAT and MAP System MAP and MAT

Climate ForecastsWeather Forecasts

ESP PreESP Pre--Adjustment TechniqueAdjustment Techniquej qj q

6 10 Day1-5 Day

6-10 Day

Long-range

Ensemble Streamflow PredictionEnsemble Streamflow PredictionEnsemble Streamflow PredictionEnsemble Streamflow Prediction

Daily RFC C CClimateForecast

Adjustments

Daily RFCForecasting•Data Ingest•Data QC•Model Updating

Current Conditions•Soil•Reservoir Levels•Streamflow

April-July

HistoricalTime Series

April-July

Time Series

All Years ofRecord

Mean ArealTime Series NWSRFS ow

Forecast

Time Series

PrecipitationTemperature

NWSRFSHydrologic

Models

Stre

amflo

TimeSeries

Time

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