# Presentation: 140759

## Precipitation Analysis and QPF  Evaluation for Hydrologic Applications

**Jay P. Breidenbach**** **
**Sr. Service Hydrologist**
- National Weather Service
- Boise Idaho

## WFO Precipitation Analysis and QPF  Evaluation for Hydrologic Applications

- Vision for Precipitation Estimation
- The Multisensor Precipitation Estimator (MPE)
- Challenges and Opportunities
- Future

## Vision for Gridded Precipitation

- HIGH RESOLUTION
-  1 km spatial, 5 min temporal
- ACCURATE
- free of bias
- low rms error
- Similar to having gage in each grid box
- DESIRED INPUT TO HYDROLOGIC APPLICATIONS AT ALL TIME  AND SPATIAL SCALES
- Flash flood monitoring
- Site Specific headwater models
- NWSRFS
- climate and drought monitoring

## Characteristics of Precipitation

- Low Spatial Correlation
- Stratiform vs Convective
- Different phases (Rain, Snow, mix)
- Orographic modification / climatology

## DATA SOURCES

**DOPPLER RADARS**
- 	-good spatial and temporal coverage
- 	-problems in mountains
- 	-non uniform bias in space and time
**GEOSTATIONARY  SATELLITES**
- -provide 15 minute  1 km imagery
- -cloud top temp based precip estimation algorithms
**NWS ASOS STATIONS WITH HEATED TIPPING BUCKETS**
**	****-**good point value estimates
**OTHER SOURCES OF AUTOMATED GAGE OBS**
- 	-timeliness and data quality problems.

## Original Vision for Precipitation InformationCirca (1994)

- Mosaic of precipitation estimates from multiple radars (Stage III) – 1 hour / 4 km
- QPF from multiple forecast offices
- Use of Satellite Data
- Use of gridded forecast data
- HAS forecast unit at RFC integrates data

## Original vision for Precipitation EstimationCirca (1994)

##  Precipitation Analysis

-  Precipitation Analysis
-  and QPF for Hydrologic Applications
- (Current Vision for operations)

- WFO and RFC Forecasters
-  Run MPE and GFE

- Compare/Evaluate

- These Data used for Hydro Products and Services

## Multisensor Precipitation Estimator

- Radar

- Gauge

- Satellite

- Forecast Hydrograph

- Regional precipitation estimate using data from multiple radars
- Mean field and local bias correction using radar estimates
- Gage and radar merging
- Incorporation of satellite precipitation estimates
- Use of PRISM data
- Manual QC

## Challenges and Opportunities

- Western Region Radar Coverage
- Display within Graphical Forecast Editor
- Verification of Quantitative Precipitation Forecasts
- Quality Control of Gage Data in MPE
- -Training
- Providing new products and services to our customers and partners
- -USGS examples
- -Climate and Drought Monitoring
- -Fire Weather
- -Information for Disaster Services
- Development of a calibration dataset for distributed hydrologic models

## Western Radar Coverage

## Western Radar Coverage -Winter

## Western Region Radar Coverage

- New SRG fields automates use of Satellite data in areas of poor radar and gage coverage.

## Western Region Radar Coverage

- New SRG fields automates use of Satellite data in areas of poor radar and gage coverage.

## QPF and QPE comparisons can now be made directly within the Graphical Forecast Editor

- 6 hr QPF forecast

- Corresponding QPE

## Verification of Precipitation Forecasts

**Boise Verify Program  **
**Calculates Error Statistics between Forecast and Observed and  different spatial scales and thresholds**

**Observed**

**Official** 0.96

**NAM** 0.69

- Spatial Averaging – 2.5 km   Threshold = 0.01 inches

## Verification of Precipitation Forecasts

**Observed**

**Official** 0.98

**NAM** 0.74

- Spatial Averaging – 50 km   Threshold = 0.01 inches

**Boise Verify Program  **
**Calculates Error Statistics between Forecast and Observed and  different spatial scales and thresholds**

## Boise Verify Program  

**Boise Verify Program  **
**Calculates error statistics between forecast and observed precipitation at  different spatial scales and thresholds**

## Training 

- Manual Quality control of gage data still an issue
- Create Case Study for local  training

## Providing new products and services to our customers and partners

- Providing new products and services to our customers and partners

- Providing new products and services to our customers and partners

## Supporting Analysis for Disaster Declarations

- User Selects Location and Date

## Multisensor Precipitation Estimator Uses

- Multisensor Precipitation Estimator

- WFO – Site specific

- WFO – QPF verification

- RFC – NWSRFS

- National Mosaics – Drought, Climate, Modeling Efforts, Other

## Summary and Future

- MPE optimizes usefulness of several different types of sensors while minimizing the impact of range degradation and beam blockage in radar data producing best possible gridded precipitation analysis available today.
- MPE can be run at both the RFC and the WFO and should serve as a core product for observed precipitation data
- Verification of QPF important both at the WFO and RFC
- Future improvements to MPE will  bring higher resolution data in space and time
- Model assisted analysis